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Bashir, Mustafa Shadi Rifaat

Overview:

Hepatobiliary and pancreatic imaging
Liver cancer (hepatocellular carcinoma)
Fatty liver, NAFLD, and NASH
Chronic liver disease and cirrhosis
Pancreatic cancer
Technical development in MRI
Quantitative imaging

Positions:

Associate Professor of Radiology

Radiology, Abdominal Imaging
School of Medicine

Member of the Duke Cancer Institute

Duke Cancer Institute
School of Medicine

Education:

M.D. 2004

M.D. — University of Iowa

Grants:

NASH Clinical Research Network

Administered By
Medicine, Gastroenterology
AwardedBy
National Institutes of Health
Role
Investigator
Start Date
April 01, 2004
End Date
June 30, 2019

TAIWANJ JKB 121-001

Administered By
Medicine, Gastroenterology
AwardedBy
TaiwanJ Pharmaceuticals Co. Ltd
Role
Co-Principal Investigator
Start Date
April 01, 2015
End Date
March 31, 2018

Role of Whole Body MRI as a Non-Invasive Technique for Characterizing Disease and Treatment Efficacy in Infantile Onset Pompe disease

Administered By
Pediatrics, Medical Genetics
AwardedBy
Genzyme Corporation
Role
Investigator
Start Date
January 01, 2016
End Date
December 31, 2017

Randomized, Blinded, Placebo-Controlled Crossover Study Assessing Association Between Gadolinum-Based Contrast Agent Adm

Administered By
Radiology, Abdominal Imaging
AwardedBy
Guerbet
Role
Principal Investigator
Start Date
January 01, 2015
End Date
December 31, 2017

NGM 15-0105

Administered By
Medicine, Gastroenterology
AwardedBy
NGM Biopharmaceuticals
Role
Co-Principal Investigator
Start Date
May 01, 2015
End Date
October 31, 2017

Duke Bashir Body Elastography MR

Administered By
Radiology, Abdominal Imaging
AwardedBy
Siemens Medical Solutions USA, Inc.
Role
Principal Investigator
Start Date
September 01, 2014
End Date
August 31, 2017

Development of an Optimized Single Breath Hold, Body MRI Protocol using 4D Dynamic Imaging for Fast, Motion-Free Dyanmic

Administered By
Radiology, Abdominal Imaging
AwardedBy
GE Healthcare
Role
Principal Investigator
Start Date
February 01, 2015
End Date
August 21, 2017

Motion-immune neuro and body MRI for challenging patient populations

Administered By
Duke-UNC Center for Brain Imaging and Analysis
AwardedBy
National Institutes of Health
Role
Co Investigator
Start Date
September 24, 2014
End Date
June 30, 2017

Body MR Imaging 2016

Administered By
Radiology, Abdominal Imaging
AwardedBy
Siemens Medical Solutions USA, Inc.
Role
Principal Investigator
Start Date
May 01, 2016
End Date
April 30, 2017

Motion Management Using 4D-MRI for Liver Cancer in Radiation Therapy

Administered By
Radiation Oncology
AwardedBy
National Institutes of Health
Role
Collaborator
Start Date
January 11, 2013
End Date
December 31, 2016

Body MR Imaging 2015

Administered By
Radiology, Abdominal Imaging
AwardedBy
Siemens Medical Solutions USA, Inc.
Role
Principal Investigator
Start Date
May 01, 2015
End Date
October 20, 2016

Impact of Fructose on Metabolism, Energy Homeostasis and MR biomarkers in NAFLD

Administered By
Radiology
AwardedBy
National Institutes of Health
Role
Co Investigator
Start Date
January 01, 2012
End Date
September 30, 2016

Body MR Imaging 2014

Administered By
Radiology, Abdominal Imaging
AwardedBy
Siemens Medical Solutions USA, Inc.
Role
Principal Investigator
Start Date
May 01, 2014
End Date
September 09, 2016

Participation in Observership Program at Duke University

Administered By
Radiology, Abdominal Imaging
AwardedBy
China International Medical Exchange Foundation
Role
Principal Investigator
Start Date
March 01, 2015
End Date
December 31, 2015

Realizing Consistent Combined Hepatic MR Arteriography and Late Arterial Phase Imaging with Eovist

Administered By
Radiology, Abdominal Imaging
AwardedBy
Bayer Healthcare Pharmaceuticals Inc
Role
Principal Investigator
Start Date
July 01, 2013
End Date
August 22, 2015

MIP1404-1301

Administered By
Duke Clinical Research Institute
AwardedBy
Molecular Insight Pharmaceuticals, Inc.
Role
Principal Investigator
Start Date
August 15, 2013
End Date
September 30, 2014
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Publications:

Multisite, multivendor validation of the accuracy and reproducibility of proton-density fat-fraction quantification at 1.5T and 3T using a fat-water phantom.

To evaluate the accuracy and reproducibility of quantitative chemical shift-encoded (CSE) MRI to quantify proton-density fat-fraction (PDFF) in a fat-water phantom across sites, vendors, field strengths, and protocols.Six sites (Philips, Siemens, and GE Healthcare) participated in this study. A phantom containing multiple vials with various oil/water suspensions (PDFF:0%-100%) was built, shipped to each site, and scanned at 1.5T and 3T using two CSE protocols per field strength. Confounder-corrected PDFF maps were reconstructed using a common algorithm. To assess accuracy, PDFF bias and linear regression with the known PDFF were calculated. To assess reproducibility, measurements were compared across sites, vendors, field strengths, and protocols using analysis of covariance (ANCOVA), Bland-Altman analysis, and the intraclass correlation coefficient (ICC).PDFF measurements revealed an overall absolute bias (across sites, field strengths, and protocols) of 0.22% (95% confidence interval, 0.07%-0.38%) and R2  > 0.995 relative to the known PDFF at each site, field strength, and protocol, with a slope between 0.96 and 1.02 and an intercept between -0.56% and 1.13%. ANCOVA did not reveal effects of field strength (P = 0.36) or protocol (P = 0.19). There was a significant effect of vendor (F = 25.13, P = 1.07 × 10-10 ) with a bias of -0.37% (Philips) and -1.22% (Siemens) relative to GE Healthcare. The overall ICC was 0.999.CSE-based fat quantification is accurate and reproducible across sites, vendors, field strengths, and protocols. Magn Reson Med 77:1516-1524, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Authors
Hernando, D; Sharma, SD; Aliyari Ghasabeh, M; Alvis, BD; Arora, SS; Hamilton, G; Pan, L; Shaffer, JM; Sofue, K; Szeverenyi, NM; Welch, EB; Yuan, Q; Bashir, MR; Kamel, IR; Rice, MJ; Sirlin, CB; Yokoo, T; Reeder, SB
MLA Citation
Hernando, D, Sharma, SD, Aliyari Ghasabeh, M, Alvis, BD, Arora, SS, Hamilton, G, Pan, L, Shaffer, JM, Sofue, K, Szeverenyi, NM, Welch, EB, Yuan, Q, Bashir, MR, Kamel, IR, Rice, MJ, Sirlin, CB, Yokoo, T, and Reeder, SB. "Multisite, multivendor validation of the accuracy and reproducibility of proton-density fat-fraction quantification at 1.5T and 3T using a fat-water phantom." Magnetic resonance in medicine 77.4 (April 2017): 1516-1524.
PMID
27080068
Source
epmc
Published In
Magnetic Resonance in Medicine
Volume
77
Issue
4
Publish Date
2017
Start Page
1516
End Page
1524
DOI
10.1002/mrm.26228

Hepatic gadoxetic acid uptake as a measure of diffuse liver disease: Where are we?

MRI has emerged as the most comprehensive noninvasive diagnostic tool for focal liver lesions and diffuse hepatobiliary disorders. The introduction of hepatobiliary contrast agents, most notably gadoxetic acid (GA), has expanded the role of MRI, particularly in the functional imaging of chronic liver diseases, such as nonalcoholic fatty liver disease (NAFLD). GA-enhanced MRI (GA-MRI) may help to distinguish between the two subgroups of NAFLD, simple steatosis and nonalcoholic steatohepatitis. Furthermore, GA-MRI can be used to stage fibrosis and cirrhosis, predict liver transplant graft survival, and preoperatively estimate the risk of liver failure should major resection be undertaken. The amount of GA uptake can be estimated, using static images, by the relative liver enhancement, hepatic uptake index, and relaxometry of T1-mapping during the hepatobiliary phase. On the contrary, the hepatic extraction fraction and liver perfusion can be measured on dynamic imaging. Importantly, there is currently no clear consensus as to which of these MR-derived parameters is the most suitable for assessing liver dysfunction. This review article aims to describe the current role of GA-enhanced MRI in quantifying liver function, primarily in diffuse hepatobiliary disorders.3 J. Magn. Reson. Imaging 2017;45:646-659.

Authors
Ba-Ssalamah, A; Bastati, N; Wibmer, A; Fragner, R; Hodge, JC; Trauner, M; Herold, CJ; Bashir, MR; Van Beers, BE
MLA Citation
Ba-Ssalamah, A, Bastati, N, Wibmer, A, Fragner, R, Hodge, JC, Trauner, M, Herold, CJ, Bashir, MR, and Van Beers, BE. "Hepatic gadoxetic acid uptake as a measure of diffuse liver disease: Where are we?." Journal of magnetic resonance imaging : JMRI 45.3 (March 2017): 646-659.
PMID
27862590
Source
epmc
Published In
Journal of Magnetic Resonance Imaging
Volume
45
Issue
3
Publish Date
2017
Start Page
646
End Page
659
DOI
10.1002/jmri.25518

Comparison of ferumoxytol-enhanced MRA with conventional angiography for assessment of severity of transplant renal artery stenosis.

To determine the accuracy of ferumoxytol-enhanced magnetic resonance angiography (MRA) in assessing the severity of transplant renal artery stenosis (TRAS), using digital subtraction angiography (DSA) as the reference standard.Our Institutional Review Board approved this retrospective, Health Insurance Portability and Accountability Act-compliant study. Thirty-three patients with documented clinical suspicion for TRAS (elevated serum creatinine, refractory hypertension, edema, and/or audible bruit) and/or concerning sonographic findings (elevated renal artery velocity and/or intraparenchymal parvus tardus waveforms) underwent a 1.5T MRA with ferumoxytol prior to DSA. All DSAs were independently reviewed by an interventional radiologist and served as the reference standard. The MRAs were reviewed by three readers who were blinded to the ultrasound and DSA findings for the presence and severity of TRAS. Sensitivity, specificity, and accuracy for identifying substantial stenoses (>50%) were determined. Intraclass correlation coefficients (ICCs) were calculated among readers. Mean differences between the percent stenosis from each MRA reader and DSA were calculated.On DSA, a total of 42 stenoses were identified in the 33 patients. The sensitivity, specificity, and accuracy of MRA in detecting substantial stenoses were 100%, 75-87.5%, and 95.2-97.6%, respectively, among the readers. There was excellent agreement among readers as to the percent stenosis (ICC = 0.82). MRA overestimated the degree of stenosis by 3.9-9.6% compared to DSA.Ferumoxytol-enhanced MRA provides high sensitivity, specificity, and accuracy for determining the severity of TRAS. Our results suggest that it can potentially be used as a noninvasive examination following ultrasound to reduce the number of unnecessary conventional angiograms.3 J. Magn. Reson. Imaging 2017;45:779-785.

Authors
Fananapazir, G; Bashir, MR; Corwin, MT; Lamba, R; Vu, CT; Troppmann, C
MLA Citation
Fananapazir, G, Bashir, MR, Corwin, MT, Lamba, R, Vu, CT, and Troppmann, C. "Comparison of ferumoxytol-enhanced MRA with conventional angiography for assessment of severity of transplant renal artery stenosis." Journal of magnetic resonance imaging : JMRI 45.3 (March 2017): 779-785.
PMID
27504713
Source
epmc
Published In
Journal of Magnetic Resonance Imaging
Volume
45
Issue
3
Publish Date
2017
Start Page
779
End Page
785
DOI
10.1002/jmri.25421

Respiratory motion artifacts during arterial phase imaging with gadoxetic acid: Can the injection protocol minimize this drawback?

To determine which of three gadoxetic acid injection techniques best reduced the contrast-related arterial-phase motion artifacts.This Institutional Review Board (IRB)-approved, retrospective study included a cohort of 78 consecutive patients who each had serial gadoxetic acid-enhanced 3.0T magnetic resonance imaging (MRI) of the liver (0.025 mmol/kg body weight) performed with at least two of three injection techniques: M1 test bolus, undiluted, power-injected 1 mL/s; M2 test bolus, diluted 50% with saline, power-injected 1 mL/s; M3 fixed delay, undiluted, manually injected. Blinded to the injection method, three readers independently rated the randomized images for arterial-phase motion artifacts, arterial-phase timing, and arterial-phase lesion visibility using a four-point Likert scale.Regarding respiratory artifacts, gadoxetic acid arterial-phase images were judged better with M3 (2.7 ± 0.7) and were significantly less than those with M1 (2.1 ± 1.1) (P = 0.0001). Arterial-phase M2 (2.50 ± 0.89) images were rated significantly better than arterial-phase M1 images (P = 0.012), but the difference between arterial-phase images with M3 and M2 scores was not statistically significant (P = 0.49). Arterial-phase timing was significantly better for M1 compared to M3, and for M2 compared to M3 (P < 0.0001 for both). The area under the curve was 0.59-0.68. However, there was no significant difference between M1 and M2 (P = 0.35). With regard to arterial-phase lesion visibility, there was no significant difference in the ratings between any of the three injection techniques (P = 0.29-0.72). Interreader agreement was moderate to substantial (κ = 0.41-0.62).A diluted, power-injected protocol (M2) seems to provide good timing and minimize artifacts compared with two other injection methods. No significant difference was found in lesion visibility between these three methods.3. J. Magn. Reson. Imaging 2017.

Authors
Polanec, SH; Bickel, H; Baltzer, PAT; Thurner, P; Gittler, F; Hodge, JC; Bashir, MR; Ba-Ssalamah, A
MLA Citation
Polanec, SH, Bickel, H, Baltzer, PAT, Thurner, P, Gittler, F, Hodge, JC, Bashir, MR, and Ba-Ssalamah, A. "Respiratory motion artifacts during arterial phase imaging with gadoxetic acid: Can the injection protocol minimize this drawback?." Journal of magnetic resonance imaging : JMRI (February 9, 2017).
PMID
28181333
Source
epmc
Published In
Journal of Magnetic Resonance Imaging
Publish Date
2017
DOI
10.1002/jmri.25657

Intravenous Gadoxetate Disodium Administration Reduces Breath-holding Capacity in the Hepatic Arterial Phase: A Multi-Center Randomized Placebo-controlled Trial.

Purpose To determine, in a multicenter double-blinded placebo-controlled trial, whether maximal hepatic arterial phase breath-holding duration is affected by gadoxetate disodium administration. Materials and Methods Institutional review board approval was obtained for this prospective multi-institutional HIPAA-compliant study; written informed consent was obtained from all subjects. At three sites, a total of 44 volunteers underwent a magnetic resonance (MR) imaging examination in which images were acquired before and dynamically after bolus injection of gadoxetate disodium, normal saline, and gadoterate meglumine, administered in random order in a single session. The technologist and volunteer were blinded to the agent. Arterial phase breath-holding duration was timed after each injection, and volunteers reported subjective symptoms. Heart rate (HR) and oxygen saturation were monitored. Images were independently analyzed for motion artifacts by three radiologists. Arterial phase breath-holding duration and motion artifacts after each agent were compared by using the Mann-Whitney U test and the McNemar test. Factors affecting the above outcomes were assessed by using a univariate, multivariable model. Results Arterial phase breath holds were shorter after gadoxetate disodium (mean, 32 seconds ± 19) than after saline (mean, 40 seconds ± 17; P < .001) or gadoterate meglumine (43 seconds ± 21, P < .001) administration. In 80% (35 of 44) of subjects, arterial phase breath holds were shorter after gadoxetate disodium than after both saline and gadoterate meglumine. Three (7%) of 44 volunteers had severe arterial phase motion artifacts after gadoxetate disodium administration, one (2%; P = .62) had them after gadoterate meglumine administration, and none (P = .25) had them after saline administration. HR and oxygen saturation changes were not significantly associated with contrast agent. Conclusion Maximal hepatic arterial phase breath-holding duration is reduced after gadoxetate disodium administration in healthy volunteers, and reduced breath-holding duration is associated with motion artifacts. © RSNA, 2016.

Authors
McClellan, TR; Motosugi, U; Middleton, MS; Allen, BC; Jaffe, TA; Miller, CM; Reeder, SB; Sirlin, CB; Bashir, MR
MLA Citation
McClellan, TR, Motosugi, U, Middleton, MS, Allen, BC, Jaffe, TA, Miller, CM, Reeder, SB, Sirlin, CB, and Bashir, MR. "Intravenous Gadoxetate Disodium Administration Reduces Breath-holding Capacity in the Hepatic Arterial Phase: A Multi-Center Randomized Placebo-controlled Trial." Radiology 282.2 (February 2017): 361-368.
PMID
27509544
Source
epmc
Published In
Radiology
Volume
282
Issue
2
Publish Date
2017
Start Page
361
End Page
368
DOI
10.1148/radiol.2016160482

Four-dimensional diffusion-weighted MR imaging (4D-DWI): a feasibility study.

Diffusion-weighted Magnetic Resonance Imaging (DWI) has been shown to be a powerful tool for cancer detection with high tumor-to-tissue contrast. This study aims to investigate the feasibility of developing a four-dimensional DWI technique (4D-DWI) for imaging respiratory motion for radiation therapy applications.Image acquisition was performed by repeatedly imaging a volume of interest (VOI) using an interleaved multislice single-shot echo-planar imaging (EPI) 2D-DWI sequence in the axial plane. Each 2D-DWI image was acquired with an intermediately low b-value (b = 500 s/mm2 ) and with diffusion-encoding gradients in x, y, and z diffusion directions. Respiratory motion was simultaneously recorded using a respiratory bellow, and the synchronized respiratory signal was used to retrospectively sort the 2D images to generate 4D-DWI. Cine MRI using steady-state free precession was also acquired as a motion reference. As a preliminary feasibility study, this technique was implemented on a 4D digital human phantom (XCAT) with a simulated pancreas tumor. The respiratory motion of the phantom was controlled by regular sinusoidal motion profile. 4D-DWI tumor motion trajectories were extracted and compared with the input breathing curve. The mean absolute amplitude differences (D) were calculated in superior-inferior (SI) direction and anterior-posterior (AP) direction. The technique was then evaluated on two healthy volunteers. Finally, the effects of 4D-DWI on apparent diffusion coefficient (ADC) measurements were investigated for hypothetical heterogeneous tumors via simulations.Tumor trajectories extracted from XCAT 4D-DWI were consistent with the input signal: the average D value was 1.9 mm (SI) and 0.4 mm (AP). The average D value was 2.6 mm (SI) and 1.7 mm (AP) for the two healthy volunteers.A 4D-DWI technique has been developed and evaluated on digital phantom and human subjects. 4D-DWI can lead to more accurate respiratory motion measurement. This has a great potential to improve the visualization and delineation of cancer tumors for radiotherapy.

Authors
Liu, Y; Zhong, X; Czito, BG; Palta, M; Bashir, MR; Dale, BM; Yin, F-F; Cai, J
MLA Citation
Liu, Y, Zhong, X, Czito, BG, Palta, M, Bashir, MR, Dale, BM, Yin, F-F, and Cai, J. "Four-dimensional diffusion-weighted MR imaging (4D-DWI): a feasibility study." Medical physics 44.2 (February 2017): 397-406.
PMID
28121369
Source
epmc
Published In
Medical physics
Volume
44
Issue
2
Publish Date
2017
Start Page
397
End Page
406
DOI
10.1002/mp.12037

Gadolinium-based contrast agents: A comprehensive risk assessment.

Gadolinium-based contrast agents (GBCAs) have been used in magnetic resonance imaging (MRI) since the 1980s and are now administered in up to 35% of all MRI examinations. While GBCAs were initially felt to carry minimal risk, the subsequent identification of GBCAs as the key etiologic factor in the development of nephrogenic systemic fibrosis (NSF) has raised concerns about the broader health impacts of gadolinium exposure. Clinicians, radiologists, and patients should be aware of the most up-to-date data pertaining to the risks of GBCA administration. Specific issues covered in this review article include immediate adverse reactions; pregnancy and lactation; and gadolinium deposition and toxicity, with a special focus on NSF. Practice recommendations based on the presented data, as well as current professional society guidelines, are provided for each section.1 J. Magn. Reson. Imaging 2017.

Authors
Fraum, TJ; Ludwig, DR; Bashir, MR; Fowler, KJ
MLA Citation
Fraum, TJ, Ludwig, DR, Bashir, MR, and Fowler, KJ. "Gadolinium-based contrast agents: A comprehensive risk assessment." Journal of magnetic resonance imaging : JMRI (January 13, 2017).
PMID
28083913
Source
epmc
Published In
Journal of Magnetic Resonance Imaging
Publish Date
2017
DOI
10.1002/jmri.25625

Liver imaging reporting and data system category 4 observations in MRI: Risk factors predicting upgrade to category 5.

To identify demographic and imaging features in magnetic resonance imaging (MRI) that are associated with upgrade of Liver Imaging Reporting and Data System (LI-RADS) category 4 (LR-4) observations to category 5 (LR-5), and to assess their effects on risk of upgrade and time to upgrade.Institutional Review Board approval was obtained for this retrospective, dual-institution Health Insurance Portability and Accountability Act (HIPAA)-compliant study. Radiologists reviewed 1.5T and 3T MRI examinations for 181 LR-4 observations in 139 patients, as well as follow-up computed tomography (CT) and MRI examinations and treatment. A stepwise multivariate Cox proportional hazards model analysis was performed to identify predictive risk factors for upgrade to LR-5, including patient demographics and LI-RADS imaging features. Overall cumulative risk of upgrade was calculated by using the Kaplan-Meier method. The cumulative risks were compared in the presence/absence of significant predictive risk factors using the log-rank test.The independent significant predictive risk factors in the 56 LR-4 observations that upgraded to LR-5 were mild-moderate T2 hyperintensity (P < 0.001; hazard ratio = 1.84), growth (P < 0.001; hazard ratio = 3.71), and hepatitis C infection (P = 0.02; hazard ratio = 1.69). The overall 6-month cumulative risk of upgrade was 32.7%. The 6-month cumulative risk rate was significantly higher in the presence of T2 hyperintensity (P = 0.03; 48.1% vs. 25.4%).For LR-4 observations, mild-moderate T2 hyperintensity, threshold growth, and hepatitis C infection are associated with significantly higher risk of upgrade to LR-5. Although mild-moderate T2 hyperintensity was the most useful risk factor for predicting upgrade, actual risk level was only mildly elevated, and the risk of upgrade associated with LR-4 observations is similar across subtypes.3 J. Magn. Reson. Imaging 2017.

Authors
Sofue, K; Burke, LMB; Nilmini, V; Alagiyawanna, M; Muir, AJ; Choudhury, KR; Jaffe, TA; Semelka, RC; Bashir, MR
MLA Citation
Sofue, K, Burke, LMB, Nilmini, V, Alagiyawanna, M, Muir, AJ, Choudhury, KR, Jaffe, TA, Semelka, RC, and Bashir, MR. "Liver imaging reporting and data system category 4 observations in MRI: Risk factors predicting upgrade to category 5." Journal of magnetic resonance imaging : JMRI (January 13, 2017).
PMID
28083902
Source
epmc
Published In
Journal of Magnetic Resonance Imaging
Publish Date
2017
DOI
10.1002/jmri.25627

Liver Imaging Reporting and Data System: an expert consensus statement.

The increasing incidence and high morbidity and mortality of hepatocellular carcinoma (HCC) have inspired the creation of the Liver Imaging Reporting and Data System (LI-RADS). LI-RADS aims to reduce variability in exam interpretation, improve communication, facilitate clinical therapeutic decisions, reduce omission of pertinent information, and facilitate the monitoring of outcomes. LI-RADS is a dynamic process, which is updated frequently. In this article, we describe the LI-RADS 2014 version (v2014), which marks the second update since the initial version in 2011.

Authors
Elsayes, KM; Kielar, AZ; Agrons, MM; Szklaruk, J; Tang, A; Bashir, MR; Mitchell, DG; Do, RK; Fowler, KJ; Chernyak, V; Sirlin, CB
MLA Citation
Elsayes, KM, Kielar, AZ, Agrons, MM, Szklaruk, J, Tang, A, Bashir, MR, Mitchell, DG, Do, RK, Fowler, KJ, Chernyak, V, and Sirlin, CB. "Liver Imaging Reporting and Data System: an expert consensus statement." Journal of hepatocellular carcinoma 4 (January 2017): 29-39.
PMID
28255543
Source
epmc
Published In
Journal of Hepatocellular Carcinoma
Volume
4
Publish Date
2017
Start Page
29
End Page
39
DOI
10.2147/jhc.s125396

Repeatability of Computerized Tomography-Based Anthropomorphic Measurements of Frailty in Patients With Pulmonary Fibrosis Undergoing Lung Transplantation.

To determine interreader and intrareader repeatability and correlations among measurements of computerized tomography-based anthropomorphic measurements in patients with pulmonary fibrosis undergoing lung transplantation.This was an institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study of 23 randomly selected subjects (19 male and 4 female; median age = 69 years; range: 66-77 years) with idiopathic pulmonary fibrosis undergoing pulmonary transplantation, who had also undergone preoperative thoracoabdominal computerized tomography. Five readers of varying imaging experience independently performed the following cross-sectional area measurements at the inferior endplate of the L3 vertebral body: right and left psoas muscles, right and left paraspinal muscles, total abdominal musculature, and visceral and subcutaneous fat. The following measurements were obtained at the inferior endplate of T6: right and left paraspinal muscles with and without including the trapezius muscles and subcutaneous fat. Three readers repeated all measurements to assess intrareader repeatability.Intrareader repeatability was nearly perfect (interclass correlation coefficients = 0.99, P < 0.001). Interreader agreement was excellent across all 5 readers (interclass correlation coefficients: 0.71-0.99, P < 0.001). Coefficients of variance between measures ranged from 3.2%-6.8% for abdominal measurements, but were higher for thoracic measurements, up to 23.9%. Correlation between total paraspinal and total psoas muscle area was strong (r2 = 0.67, P < 0.001). Thoracic and abdominal musculature had a weaker correlation (r2 = 0.35-0.38, P < 0.001).Measures of thoracic and abdominal muscle and fat area are highly repeatable in patients with pulmonary fibrosis undergoing lung transplantation. Measures of muscle area are strongly correlated among abdominal locations, but inversely correlated between abdominal and thoracic locations.

Authors
McClellan, T; Allen, BC; Kappus, M; Bhatti, L; Dafalla, RA; Snyder, LD; Bashir, MR
MLA Citation
McClellan, T, Allen, BC, Kappus, M, Bhatti, L, Dafalla, RA, Snyder, LD, and Bashir, MR. "Repeatability of Computerized Tomography-Based Anthropomorphic Measurements of Frailty in Patients With Pulmonary Fibrosis Undergoing Lung Transplantation." Current problems in diagnostic radiology (December 29, 2016).
PMID
28215519
Source
epmc
Published In
Current Problems in Diagnostic Radiology
Publish Date
2016
DOI
10.1067/j.cpradiol.2016.12.009

Increased parenchymal damage and steatohepatitis in Caucasian non-alcoholic fatty liver disease patients with common IL1B and IL6 polymorphisms

Authors
Nelson, JE; Handa, P; Aouizerat, B; Wilson, L; Vemulakonda, LA; Yeh, MM; Kowdley, KV
MLA Citation
Nelson, JE, Handa, P, Aouizerat, B, Wilson, L, Vemulakonda, LA, Yeh, MM, and Kowdley, KV. "Increased parenchymal damage and steatohepatitis in Caucasian non-alcoholic fatty liver disease patients with common IL1B and IL6 polymorphisms." Alimentary Pharmacology & Therapeutics 44.11-12 (December 2016): 1253-1264.
Source
crossref
Published In
Alimentary Pharmacology & Therapeutics
Volume
44
Issue
11-12
Publish Date
2016
Start Page
1253
End Page
1264
DOI
10.1111/apt.13824

Natural history of liver imaging reporting and data system category 4 nodules in MRI.

The purpose of this study was to characterize the MR imaging features and outcomes of liver imaging reporting and data system (LI-RADS) category 4 (LR4) nodules, with an emphasis on upgrade to category 5 (LR5) and development of contraindications to curative therapy.Institutional review board approval was obtained for this retrospective, dual-institutional Health Insurance Portability and Accountability Act-compliant study. The requirement for informed consent was waived. Contrast-enhanced MRI studies performed on patients with cirrhosis were retrospectively assessed using LI-RADS 2014 by at least two readers. All nodules were individually evaluated to determine their major imaging features at diagnosis, and follow-up data were used to determine the associated imaging outcomes.One hundred eighty-one untreated LR4 nodules in 139 patients had adequate imaging and follow-up for inclusion in the study. Most (61% [111/181]) of these demonstrated arterial phase hyperenhancement, washout, and diameter less than 20 mm. During the follow-up period (median 163 days), 31% (56/181) of the nodules upgraded to LR5, 40% (73/181) remained stable, and 29% (52/181) downgraded. Of the nodules that upgraded, 61% (34/56) increased their size category and 54% (30/56) developed newly visualized capsules. No LR4 nodules developed venous invasion, satellites nodules, or new intrahepatic or extrahepatic metastatic disease. 75% (42/56) of the nodules that upgraded to LR5 did so within 6 months.Approximately one-third of LR4 nodules upgrade to LR5, and the short-term risk of developing venous invasion or metastasis is very low.

Authors
Burke, LMB; Sofue, K; Alagiyawanna, M; Nilmini, V; Muir, AJ; Choudhury, KR; Semelka, RC; Bashir, MR
MLA Citation
Burke, LMB, Sofue, K, Alagiyawanna, M, Nilmini, V, Muir, AJ, Choudhury, KR, Semelka, RC, and Bashir, MR. "Natural history of liver imaging reporting and data system category 4 nodules in MRI." Abdominal radiology (New York) 41.9 (September 2016): 1758-1766.
PMID
27145771
Source
epmc
Published In
Abdominal radiology (New York)
Volume
41
Issue
9
Publish Date
2016
Start Page
1758
End Page
1766
DOI
10.1007/s00261-016-0762-3

Stability of liver proton density fat fraction and changes in R 2* measurements induced by administering gadoxetic acid at 3T MRI.

To assess changes in liver proton density fat fraction (PDFF) and R 2* measurements in the presence of changes in tissue relaxation rates induced by administrating gadoxetic acid, using two different image reconstruction methods at 3T MRI.Forty-five patients were imaged at 3T with chemical-shift-based MRI sequences before and 20 min after administration of gadoxetic acid. Image reconstructions were performed using hybrid and complex methods to obtain PDFF and R 2* images. A single radiologist measured PDFF and R 2* values on precontrast and postcontrast images. Precontrast and postcontrast PDFF values were compared using intraclass correlation coefficient (ICC), linear regression, and Bland-Altman analysis. Changes in R 2* values from precontrast to postcontrast were correlated with relative liver enhancement (RLE) based on signal intensities on T 1-weighted images using Spearman's rank correlation.PDFF values were similar between precontrast and postcontrast images (ICC = 0.99, linear regression slopes = 0.98, mean difference = -0.21 to -0.31%). PDFF measurements were stable between precontrast and postcontrast images. Changes in R 2* values were correlated with RLE (p < 0.001, r = 0.49-0.71).PDFF measurements from both image reconstruction methods are stable in the presence of changes in tissue relaxation rates after administering gadoxetic acid at 3T MRI. Changes in R 2* values correlate with established measures of gadoxetic acid uptake based on T 1-weighted images.

Authors
Sofue, K; Zhong, X; Nickel, MD; Dale, BM; Bashir, MR
MLA Citation
Sofue, K, Zhong, X, Nickel, MD, Dale, BM, and Bashir, MR. "Stability of liver proton density fat fraction and changes in R 2* measurements induced by administering gadoxetic acid at 3T MRI." Abdominal radiology (New York) 41.8 (August 2016): 1555-1564.
PMID
27052456
Source
epmc
Published In
Abdominal radiology (New York)
Volume
41
Issue
8
Publish Date
2016
Start Page
1555
End Page
1564
DOI
10.1007/s00261-016-0728-5

Diagnostic performance of MDCT in identifying closed loop small bowel obstruction.

To assess the diagnostic performance of MDCT in the diagnosis of closed loop small bowel obstruction.One hundred fifty patients with CT reports including "small bowel obstruction (SBO)" between 1/30/2011 and 12/4/2012 were included (65 men, 85 women, mean age 63 years). CT examinations were independently and blindly reviewed by five radiologists to determine the presence of closed loop obstruction (CL-SBO) and to assess findings of bowel ischemia. Clinical records were reviewed to determine management and operative findings. Using operative findings as a gold standard, reader agreement for the diagnosis of and the CT findings associated with CLO was analyzed using Pearson's correlation (r). Positive predictive value (PPV) and negative predictive value for the diagnosis of CL-SBO and CT signs of bowel ischemia were analyzed.Eighty-eight of 150 patients underwent operative intervention for SBO and 24/88 were considered CL-SBO operatively. Average reader sensitivity and specificity for CL-SBO was 53 % (95 % CI 44-63 %) and 83 % (95 % CI 79-87 %). Reader agreement on CL-SBO was poor to moderate (K = 0.39-0.63). Reader agreement for CT signs of bowel ischemia resulting in a diagnosis of CL-SBO was weak (r = 0.19-0.32).The CT diagnosis of CL-SBO is complex and associated imaging findings have variable sensitivity for predicting a closed loop operative diagnosis. CT can be helpful in excluding a closed loop component in patients with SBO.

Authors
Makar, RA; Bashir, MR; Haystead, CM; Iseman, C; Mayes, N; Hebert, S; Allen, BC; Bhattacharya, SD; Choudhury, KR; Jaffe, TA
MLA Citation
Makar, RA, Bashir, MR, Haystead, CM, Iseman, C, Mayes, N, Hebert, S, Allen, BC, Bhattacharya, SD, Choudhury, KR, and Jaffe, TA. "Diagnostic performance of MDCT in identifying closed loop small bowel obstruction." Abdominal radiology (New York) 41.7 (July 2016): 1253-1260.
PMID
26830421
Source
epmc
Published In
Abdominal radiology (New York)
Volume
41
Issue
7
Publish Date
2016
Start Page
1253
End Page
1260
DOI
10.1007/s00261-016-0656-4

How reader perception of capsule affects interpretation of washout in hypervascular liver nodules in patients at risk for hepatocellular carcinoma.

To determine whether reader perception of a capsule affects reader interpretation of washout in hypervascular liver nodules at dynamic magnetic resonance imaging (MRI) in patients at risk for hepatocellular carcinoma (HCC).This retrospective study was Institutional Review Board (IRB)-approved and Health Insurance Portability and Accountability Act (HIPAA)-compliant, with waiver of informed consent. MRI reports for 111 hypervascular liver nodules (median 2.0 cm, range 1.0-17.8 cm) in 62 patients were reviewed, and the presence/absence of capsule and washout were recorded for one reading. A second independent study reading was also performed. The signal intensity ratio (SIR) for each nodule and liver parenchyma was measured. An objective SIR threshold was identified for nodules without capsules that correctly classified the presence/absence of washout, then applied to nodules with capsules to classify them as having / not having objective washout. Nodules were categorized as definite / not definite HCC using subjective and objective washout, based on LI-RADS, OPTN, AASLD, and EASL criteria, and proportions compared using McNemar's test.Agreement on nodule features was high for Readings 1 and 2 (κ = 0.70-0.82). For Reading 1, 71 nodules lacked capsules (43 with and 28 without subjective washout); an SIR threshold of 0.88 classified the presence/absence of washout correctly in 94% (67/71, P < 0.001). Forty nodules had capsules; although all had subjective washout (100%, 40/40), 75% (30/40) had objective washout (P < 0.05). Using objective washout caused 4.5% (3/66; LI-RADS, OPTN) and 12% (10/83; AASLD, EASL) of nodules to be recategorized from definite HCC to not definite HCC.Reader perception of capsule affects interpretation of washout. This effect can influence nodule categorization using imaging-based diagnostic systems. J. Magn. Reson. Imaging 2016;43:1337-1345.

Authors
Sofue, K; Sirlin, CB; Allen, BC; Nelson, RC; Berg, CL; Bashir, MR
MLA Citation
Sofue, K, Sirlin, CB, Allen, BC, Nelson, RC, Berg, CL, and Bashir, MR. "How reader perception of capsule affects interpretation of washout in hypervascular liver nodules in patients at risk for hepatocellular carcinoma." Journal of magnetic resonance imaging : JMRI 43.6 (June 2016): 1337-1345.
PMID
26559157
Source
epmc
Published In
Journal of Magnetic Resonance Imaging
Volume
43
Issue
6
Publish Date
2016
Start Page
1337
End Page
1345
DOI
10.1002/jmri.25094

Can combining triple-arterial phase acquisition with fluoroscopic triggering provide both optimal early and late hepatic arterial phase images during gadoxetic acid-enhanced MRI?

To determine whether triple-arterial phase acquisition with fluoroscopic triggering can provide both well-timed early and late hepatic arterial phase (HAP) images more frequently than when using a fixed-time delay during gadoxetic acid-enhanced magnetic resonance imaging (MRI).Written informed consent was obtained for this Institutional Review Board (IRB)-approved prospective, Health Insurance Portability and Accountability Act (HIPAA)-compliant study. Ninety patients underwent gadoxetic acid-enhanced MRI at 3T with a single-breath-hold triple-arterial phase acquisition using either a fixed-time delay (n = 45) or fluoroscopic triggering injection protocol (n = 45). Three radiologists, blinded to method of timing and other data, independently determined whether well-timed early or late HAP were obtained for each arterial phase image set and assessed for transient severe motion (TSM). Rates of successful HAP acquisitions and of TSM were compared between the two protocols using χ(2) or Fisher's exact test.The rate of successful acquisition of late HAP images was similar in the two groups (93% [42/45] for fixed-time delay vs. 98% [44/45] for fluoroscopic triggering, P = 0.62). There was a trend toward higher rates of successful acquisition of both early and late HAP images in the fluoroscopic triggering group (69% [31/45] vs. 49% [22/45], P = 0.05). TSM occurred in five patients (6% [5/90]) and at similar frequencies in the two groups (2% [1/45] vs. 9% [4/45], P = 0.36).Triple-arterial phase acquisition with fluoroscopic triggering tended to provide both well-timed early and late HAP images more frequently than when using a fixed-time delay during gadoxetic acid-enhanced MRI.

Authors
Sofue, K; Marin, D; Jaffe, TA; Nelson, RC; Bashir, MR
MLA Citation
Sofue, K, Marin, D, Jaffe, TA, Nelson, RC, and Bashir, MR. "Can combining triple-arterial phase acquisition with fluoroscopic triggering provide both optimal early and late hepatic arterial phase images during gadoxetic acid-enhanced MRI?." Journal of magnetic resonance imaging : JMRI 43.5 (May 2016): 1073-1081.
PMID
26469796
Source
epmc
Published In
Journal of Magnetic Resonance Imaging
Volume
43
Issue
5
Publish Date
2016
Start Page
1073
End Page
1081
DOI
10.1002/jmri.25079

Safety and technique of ferumoxytol administration for MRI.

Ferumoxytol is an ultrasmall superparamagnetic iron oxide agent marketed for the treatment of anemia. There has been increasing interest in its properties as an MRI contrast agent as well as greater awareness of its adverse event profile. This mini-review summarizes the current state of knowledge of the risks of ferumoxytol and methods of administration.

Authors
Vasanawala, SS; Nguyen, K-L; Hope, MD; Bridges, MD; Hope, TA; Reeder, SB; Bashir, MR
MLA Citation
Vasanawala, SS, Nguyen, K-L, Hope, MD, Bridges, MD, Hope, TA, Reeder, SB, and Bashir, MR. "Safety and technique of ferumoxytol administration for MRI." Magnetic resonance in medicine 75.5 (May 2016): 2107-2111. (Review)
PMID
26890830
Source
epmc
Published In
Magnetic Resonance in Medicine
Volume
75
Issue
5
Publish Date
2016
Start Page
2107
End Page
2111
DOI
10.1002/mrm.26151

Computed Tomography-Based Limb Volume Measurements for Isolated Limb Infusion in Melanoma.

Despite advances in cross-sectional imaging, chemotherapeutic dosing for isolated limb infusion (ILI) in melanoma is currently calculated through cumbersome and potentially imprecise manual measurements. The primary objective of this study was to examine the feasibility of using computed tomography (CT) to calculate limb volume, its concordance with manual measurement, and its ability to predict clinical response and toxicity in patients undergoing ILI.A retrospective analysis of all patients undergoing lower extremity ILI at Duke University Medical Center between 2003 and 2014 was performed. Data pertaining to manually measured limb volume, chemotherapeutic dosing, and patient outcome was obtained. CT-based measurements of limb volume were performed in all patients for whom imaging was available and subsequently compared with manually measured values.CT data were sufficient for measurement in 73 patients. The mean measurement time was 4.61 ± 2.13 min. Although average CT-based measurements were 1.20 L higher in the case of lower limbs, they correlated well with those obtained manually (r (2) = 0.90). Unlike manual measurement, patients with complete responses to chemotherapy had smaller limb volumes than those with disease progression as measured by CT (9.3 vs. 10.7 L; p = .038). Patients suffering grade 3 and 4 toxicities also had statistically lower limb volumes as measured by CT than those who did not (p < .05).CT-based limb volume measurement is feasible for chemotherapy dosing in patients undergoing ILI for melanoma and has predictive value with respect to clinical response and toxicity.

Authors
Brys, AK; Bhatti, L; Bashir, MR; Jaffe, TA; Beasley, GM; Nath, NS; Salama, AKS; Tyler, DS; Mosca, PJ
MLA Citation
Brys, AK, Bhatti, L, Bashir, MR, Jaffe, TA, Beasley, GM, Nath, NS, Salama, AKS, Tyler, DS, and Mosca, PJ. "Computed Tomography-Based Limb Volume Measurements for Isolated Limb Infusion in Melanoma." Annals of surgical oncology 23.4 (April 2016): 1090-1095.
PMID
26572755
Source
epmc
Published In
Annals of Surgical Oncology
Volume
23
Issue
4
Publish Date
2016
Start Page
1090
End Page
1095
DOI
10.1245/s10434-015-4972-7

Consensus report from the 7th International Forum for Liver Magnetic Resonance Imaging.

Liver-specific MRI is a fast-growing field, with technological and protocol advancements providing more robust imaging and allowing a greater depth of information per examination. This article reports the evidence for, and expert thinking on, current challenges in liver-specific MRI, as discussed at the 7th International Forum for Liver MRI, which was held in Shanghai, China, in October 2013.Topics discussed included the role of gadoxetic acid-enhanced MRI in the differentiation of focal nodular hyperplasia from hepatocellular adenoma and small hepatocellular carcinoma (HCC) from small intrahepatic cholangiocarcinoma (in patients with chronic liver disease), the differentiation of low-grade dysplastic nodule (DN) from pre-malignant high-grade DN and early HCC, and treatment planning and assessment of treatment response for patients with HCC and colorectal liver metastasis. Optimization of the gadoxetic acid-enhanced MRI protocol to gain robust arterial and hepatobiliary phase images was also discussed.Gadoxetic acid-enhanced MRI demonstrates added value for the detection and characterization of focal liver lesions and shows promise in a number of new indications, including regional liver functional assessment and patient monitoring after therapy; however, more data are needed in some areas, and further developments are needed to translate cutting-edge techniques into clinical practice.Liver-specific MRI is a fast-growing field, with many technological and protocol advancements. Gadoxetic acid-enhanced MRI demonstrates value for detecting and characterizing focal liver lesions. Gadoxetic acid-enhanced MRI shows promise in regional functional assessment and patient monitoring. Further developments are needed to translate cutting-edge techniques into clinical practice.

Authors
Merkle, EM; Zech, CJ; Bartolozzi, C; Bashir, MR; Ba-Ssalamah, A; Huppertz, A; Lee, JM; Ricke, J; Sakamoto, M; Sirlin, CB; Ye, S-L; Zeng, M
MLA Citation
Merkle, EM, Zech, CJ, Bartolozzi, C, Bashir, MR, Ba-Ssalamah, A, Huppertz, A, Lee, JM, Ricke, J, Sakamoto, M, Sirlin, CB, Ye, S-L, and Zeng, M. "Consensus report from the 7th International Forum for Liver Magnetic Resonance Imaging." European radiology 26.3 (March 2016): 674-682.
PMID
26070500
Source
epmc
Published In
European Radiology
Volume
26
Issue
3
Publish Date
2016
Start Page
674
End Page
682
DOI
10.1007/s00330-015-3873-2

Isolated recto-sigmoid colitis: a new imaging pattern of ipilimumab-associated colitis.

The purpose of this study is to describe typical CT findings and distinct imaging patterns of ipilimumab-associated colitis in immunotherapeutic treatment of melanoma.This HIPAA-compliant retrospective study included 86 patients with melanoma imaged with CT or PET/CT of the abdomen and pelvis during or shortly after administration of ipilimumab. Twelve of 86 patients (14%) developed symptoms of colitis and underwent CT imaging of the abdomen and pelvis while symptomatic. Two radiologists reviewed CT images to evaluate for the presence of CT findings of colitis including mesenteric vessel engorgement, pericolonic inflammatory change, hyperenhancement of colonic mucosa, colonic wall thickening, fluid-filled colonic distension, pneumoperitoneum, pneumatosis, and diverticulosis in the inflamed segment of colon. One nuclear medicine radiologist reviewed PET images for abnormally increased FDG uptake in the colon. The diagnosis of ipilimumab-associated colitis was made based on clinical presentation, imaging findings, and laboratory data.Common CT findings of ipilimumab-associated colitis included colonic mucosal hyperenhancement (10/12 [83%]), mesenteric vessel engorgement (9/12 [75.0%]), colonic wall thickening (9/12 [75%]), and pericolonic fat stranding (2/12 [16%]). No patient developed pneumatosis or pneumoperitoneum. Diffuse colitis was present in 4/12 (33%) patients. Segmental colitis with associated diverticulosis (was present in 2/12 (17%) patients). A third pattern, isolated recto-sigmoid colitis without diverticulosis, was observed in 6/12 (50%) patients. All patients with colitis demonstrated recto-sigmoid involvement.A third radiologic pattern of ipilimumab-associated colitis was observed in this study: isolated recto-sigmoid colitis without diverticulosis. All patterns of ipilimumab-associated colitis include recto-sigmoid involvement.

Authors
Barina, AR; Bashir, MR; Howard, BA; Hanks, BA; Salama, AK; Jaffe, TA
MLA Citation
Barina, AR, Bashir, MR, Howard, BA, Hanks, BA, Salama, AK, and Jaffe, TA. "Isolated recto-sigmoid colitis: a new imaging pattern of ipilimumab-associated colitis." Abdominal radiology (New York) 41.2 (February 2016): 207-214.
PMID
26867901
Source
epmc
Published In
Abdominal radiology (New York)
Volume
41
Issue
2
Publish Date
2016
Start Page
207
End Page
214
DOI
10.1007/s00261-015-0560-3

Differences in Liver Imaging and Reporting Data System Categorization Between MRI and CT.

The purpose of this study is to determine whether focal liver observations are categorized differently by CT and MRI using the Liver Imaging and Reporting Data System (LI-RADS).We performed a retrospective review of 58 patients at risk for hepatocellular carcinoma who underwent liver protocol CT and MRI within 1 month of each other. Two readers assigned a LI-RADS category for all focal liver observations in consensus. A significant category upgrade was defined as a change from LI-RADS categories 1 and 2 or nonvisualization to LI-RADS categories 3-5, from LI-RADS category 3 to category 4 or 5, from LI-RADS category 4 to category 5, or from any category to LI-RADS category 5V. A significant downgrade was defined as a change from LI-RADS category 5 to categories 1-4, from LI-RADS category 4 to categories 1-3, or from LI-RADS category 3 to categories 1 or 2.The LI-RADS category was different between CT and MRI for 77.2% (176/228) of observations. A significant upgrade occurred on MRI for 42.5% (97/228) of observations because of nonvisualization by CT (n = 78), capsule (n = 8), arterial hyperenhancement (n = 4), intratumoral fat (n = 2), larger size (n = 2), tumor in portal vein (n = 2), and wash-out (n = 1). Of these 97 upgraded observations, two were upgraded to LI-RADS category 5V, 15 were upgraded to category 5, and 13 were upgraded to category 4. A significant downgrade occurred on MRI for 8.8% (20/228) of observations because of marked T2 hyperintensity (n = 14), smaller size (n = 2), wedge shape (n = 2), and marked T2 hypointensity (n = 2).LI-RADS categorization of focal liver observations is dependent on imaging modality. MRI results in both upgraded and downgraded categorization compared with CT in an important proportion of observations.

Authors
Corwin, MT; Fananapazir, G; Jin, M; Lamba, R; Bashir, MR
MLA Citation
Corwin, MT, Fananapazir, G, Jin, M, Lamba, R, and Bashir, MR. "Differences in Liver Imaging and Reporting Data System Categorization Between MRI and CT." AJR. American journal of roentgenology 206.2 (February 2016): 307-312.
PMID
26797357
Source
epmc
Published In
AJR. American journal of roentgenology
Volume
206
Issue
2
Publish Date
2016
Start Page
307
End Page
312
DOI
10.2214/ajr.15.14788

Initial Evaluation of Four Dimensional Diffusion-Weighted MR Imaging (4D-DWI) in Phantom and Human Subject

Authors
Liu, Y; Yin, FF; Czito, B; Bashir, MR; Cai, J
MLA Citation
Liu, Y, Yin, FF, Czito, B, Bashir, MR, and Cai, J. "Initial Evaluation of Four Dimensional Diffusion-Weighted MR Imaging (4D-DWI) in Phantom and Human Subject." November 1, 2015.
Source
wos-lite
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
93
Issue
3
Publish Date
2015
Start Page
E604
End Page
E604

POCS-based reconstruction of multiplexed sensitivity encoded MRI (POCSMUSE): A general algorithm for reducing motion-related artifacts.

A projection onto convex sets reconstruction of multiplexed sensitivity encoded MRI (POCSMUSE) is developed to reduce motion-related artifacts, including respiration artifacts in abdominal imaging and aliasing artifacts in interleaved diffusion-weighted imaging.Images with reduced artifacts are reconstructed with an iterative projection onto convex sets (POCS) procedure that uses the coil sensitivity profile as a constraint. This method can be applied to data obtained with different pulse sequences and k-space trajectories. In addition, various constraints can be incorporated to stabilize the reconstruction of ill-conditioned matrices.The POCSMUSE technique was applied to abdominal fast spin-echo imaging data, and its effectiveness in respiratory-triggered scans was evaluated. The POCSMUSE method was also applied to reduce aliasing artifacts due to shot-to-shot phase variations in interleaved diffusion-weighted imaging data corresponding to different k-space trajectories and matrix condition numbers.Experimental results show that the POCSMUSE technique can effectively reduce motion-related artifacts in data obtained with different pulse sequences, k-space trajectories and contrasts.POCSMUSE is a general post-processing algorithm for reduction of motion-related artifacts. It is compatible with different pulse sequences, and can also be used to further reduce residual artifacts in data produced by existing motion artifact reduction methods.

Authors
Chu, M-L; Chang, H-C; Chung, H-W; Truong, T-K; Bashir, MR; Chen, N-K
MLA Citation
Chu, M-L, Chang, H-C, Chung, H-W, Truong, T-K, Bashir, MR, and Chen, N-K. "POCS-based reconstruction of multiplexed sensitivity encoded MRI (POCSMUSE): A general algorithm for reducing motion-related artifacts." Magnetic resonance in medicine 74.5 (November 2015): 1336-1348.
Website
http://hdl.handle.net/10161/9460
PMID
25394325
Source
epmc
Published In
Magnetic Resonance in Medicine
Volume
74
Issue
5
Publish Date
2015
Start Page
1336
End Page
1348
DOI
10.1002/mrm.25527

Interexamination repeatability and spatial heterogeneity of liver iron and fat quantification using MRI-based multistep adaptive fitting algorithm.

To assess the interexamination repeatability and spatial heterogeneity of liver iron and fat measurements using a magnetic resonance imaging (MRI)-based multistep adaptive fitting algorithm.This prospective observational study was Institutional Review Board-approved and Health Insurance Portability and Accountability Act-compliant. Written informed consent was waived. In all, 150 subjects were imaged on 3T MRI systems. A whole-liver volume acquisition was performed twice using a six-echo 3D spoiled gradient echo sequence during two immediately adjacent examinations. Colocalized regions of interest (ROIs) in three different hepatic segments were placed for R2 * and proton density fat fraction (PDFF) measurements by two readers independently. Mean R2 * and PDFF values between readers and acquisitions were compared using the Wilcoxon signed-rank test, intraclass correlation coefficients (ICCs), linear regression, Bland-Altman analysis, and analysis of variance (ANOVA).The mean R2 * and PDFF values across all ROIs and measurements were 51.2 ± 25.2 s(-1) and 6.9 ± 6.4%, respectively. Mean R2 * and PDFF values showed no significant differences between the two acquisitions (P = 0.05-0.87). Between the two acquisitions, R2 * and PDFF values demonstrated almost perfect agreement (ICCs = 0.979-0.994) and excellent correlation (R(2)  = 0.958-0.989). Bland-Altman analysis also demonstrated excellent agreement. In the ANOVA, the individual patient and ROI location were significant effects for both R2 * and PDFF values (P < 0.05).MRI-based R2 * and PDFF measurements are repeatable between examinations. Between-measurement changes in R2 * of more than 10.1 s(-1) and in PDFF of more than 1.7% are likely due to actual tissue changes. Liver iron and fat content are variable between hepatic segments.

Authors
Sofue, K; Mileto, A; Dale, BM; Zhong, X; Bashir, MR
MLA Citation
Sofue, K, Mileto, A, Dale, BM, Zhong, X, and Bashir, MR. "Interexamination repeatability and spatial heterogeneity of liver iron and fat quantification using MRI-based multistep adaptive fitting algorithm." Journal of magnetic resonance imaging : JMRI 42.5 (November 2015): 1281-1290.
PMID
25920074
Source
epmc
Published In
Journal of Magnetic Resonance Imaging
Volume
42
Issue
5
Publish Date
2015
Start Page
1281
End Page
1290
DOI
10.1002/jmri.24922

Magnetic resonance imaging of acute appendicitis in pregnancy: a 5-year multiinstitutional study.

The purpose of this study was to determine the diagnostic performance of magnetic resonance imaging (MRI) in the diagnosis of acute appendicitis during pregnancy in a multiinstitutional study.In this multicenter retrospective study, the cases of pregnant women who underwent MRI evaluation of abdominal or pelvic pain and who had clinical suspicion of acute appendicitis between June 1, 2009, and July 31, 2014, were reviewed. All MRI examinations with positive findings for acute appendicitis were confirmed with surgical pathologic information. Sensitivity, specificity, negative predictive values, and positive predictive values were calculated. Receiver operating characteristic curves were generated, and area under the curve analysis was performed for each participating institution.Of the cases that were evaluated, 9.3% (66/709) had MRI findings of acute appendicitis. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive values were 96.8%, 99.2%, 99.0%, 92.4%, and 99.7%, respectively. There was no statistically significant difference between centers that were included in the study (pair-wise probability values ranged from 0.12-0.99).MRI is useful and reproducible in the diagnosis of suspected acute appendicitis during pregnancy.

Authors
Burke, LMB; Bashir, MR; Miller, FH; Siegelman, ES; Brown, M; Alobaidy, M; Jaffe, TA; Hussain, SM; Palmer, SL; Garon, BL; Oto, A; Reinhold, C; Ascher, SM; Demulder, DK; Thomas, S; Best, S; Borer, J; Zhao, K; Pinel-Giroux, F; De Oliveira, I; Resende, D; Semelka, RC
MLA Citation
Burke, LMB, Bashir, MR, Miller, FH, Siegelman, ES, Brown, M, Alobaidy, M, Jaffe, TA, Hussain, SM, Palmer, SL, Garon, BL, Oto, A, Reinhold, C, Ascher, SM, Demulder, DK, Thomas, S, Best, S, Borer, J, Zhao, K, Pinel-Giroux, F, De Oliveira, I, Resende, D, and Semelka, RC. "Magnetic resonance imaging of acute appendicitis in pregnancy: a 5-year multiinstitutional study." American journal of obstetrics and gynecology 213.5 (November 2015): 693.e1-693.e6.
PMID
26215327
Source
epmc
Published In
American Journal of Obstetrics & Gynecology
Volume
213
Issue
5
Publish Date
2015
Start Page
693.e1
End Page
693.e6
DOI
10.1016/j.ajog.2015.07.026

Diagnostic performance of imaging criteria for distinguishing autoimmune cholangiopathy from primary sclerosing cholangitis and bile duct malignancy.

To determine the diagnostic performance of imaging criteria for distinguishing Ig-G4-associated autoimmune cholangiopathy (IAC) from primary sclerosing cholangitis (PSC) and bile duct malignancy.A medical records search between January 2008 and October 2013 identified 10 patients (8 M, 2 F, mean age 61 years, range 34-82) with a clinical diagnosis of IAC. Fifteen cases of PSC (6 M, 9 F, mean age 50, range 22-65) and 15 cases of biliary malignancy (7 M, 8 F, mean age 65, range 48-84) were randomly selected for comparative analysis. Three abdominal radiologists independently reviewed MRI with MRCP (n = 32) or CT (n = 8) and ERCP (n = 8) for the following IAC imaging predictors: single-wall bile duct thickness >2.5 mm, continuous biliary involvement, gallbladder involvement, liver disease, peribiliary mass, or pancreatic and renal abnormalities. Each radiologist provided an imaging-based diagnosis (IAC, PSC, or cancer). Imaging predictor sensitivity, specificity, accuracy, and association with IAC using Fisher's exact test. Inter-reader agreement determined using Fleiss' kappa statistics.For diagnosis of IAC, sensitivities and specificities were high (70-93%). Pancreatic abnormality was strongest predictor for distinguishing IAC from PSC and cancer, with high diagnostic performance (70-80% sensitivity, 87-97% specificity), significant association (p < 0.01), and moderate inter-reader agreement (κ = 0.59). Continuous biliary involvement was moderately predictive (50-100% sensitivity, 53-83% specificity) and trended toward significant association in distinguishing from PSC (p = 0.01-0.19), but less from cancer (p = 0.06-0.62).It remains difficult to distinguish IAC from PSC or bile duct malignancy based on imaging features alone. The presence of pancreatic abnormalities, including peripancreatic rind, atrophy, abnormal enhancement, or T2 signal intensity, strongly favors a diagnosis of IAC.

Authors
Gardner, CS; Bashir, MR; Marin, D; Nelson, RC; Choudhury, KR; Ho, LM
MLA Citation
Gardner, CS, Bashir, MR, Marin, D, Nelson, RC, Choudhury, KR, and Ho, LM. "Diagnostic performance of imaging criteria for distinguishing autoimmune cholangiopathy from primary sclerosing cholangitis and bile duct malignancy." Abdominal imaging 40.8 (October 2015): 3052-3061.
PMID
26350286
Source
epmc
Published In
Abdominal Imaging
Volume
40
Issue
8
Publish Date
2015
Start Page
3052
End Page
3061
DOI
10.1007/s00261-015-0543-4

Cross-sectional and longitudinal agreement of magnetic resonance imaging proton density fat fraction with pathologist grading of hepatic steatosis in adults with nonalcoholic steatohepatitis in a multi-center trial

Authors
Middleton, MS; Heba, E; Hooker, CA; Neuschwander-Tetri, BA; Bashir, MR; Fowler, K; Sandrasegaran, KE; Brunt, EM; Kleiner, DE; Doo, E; Van Natta, ML; Tonascia, J; Loomba, R; Sirlin, CB
MLA Citation
Middleton, MS, Heba, E, Hooker, CA, Neuschwander-Tetri, BA, Bashir, MR, Fowler, K, Sandrasegaran, KE, Brunt, EM, Kleiner, DE, Doo, E, Van Natta, ML, Tonascia, J, Loomba, R, and Sirlin, CB. "Cross-sectional and longitudinal agreement of magnetic resonance imaging proton density fat fraction with pathologist grading of hepatic steatosis in adults with nonalcoholic steatohepatitis in a multi-center trial." October 2015.
Source
wos-lite
Published In
Hepatology
Volume
62
Publish Date
2015
Start Page
1255A
End Page
1255A

Imaging in Patients with Cirrhosis: Current Evidence.

There have been major changes in the management and reporting of hepatocellular carcinoma (HCC) in the last decade. Cross-sectional imaging is now pivotal in the management of cirrhotic patients, in particular in the diagnosis and staging of HCC. Although diagnostic systems have become relatively well developed, approximately one-third of HCC nodules may have an atypical appearance, necessitating ancillary testing, close follow-up, or biopsy. The introduction of standardized diagnostic and reporting systems has improved communication between radiologists and clinicians, but there remains substantial disagreement between radiologists in feature assignment and nodule characterization.

Authors
Bashir, MR; Hussain, HK
MLA Citation
Bashir, MR, and Hussain, HK. "Imaging in Patients with Cirrhosis: Current Evidence." Radiologic clinics of North America 53.5 (September 2015): 919-931.
PMID
26321446
Source
epmc
Published In
Radiologic Clinics of North America
Volume
53
Issue
5
Publish Date
2015
Start Page
919
End Page
931
DOI
10.1016/j.rcl.2015.05.006

Concordance of hypervascular liver nodule characterization between the organ procurement and transplant network and liver imaging reporting and data system classifications.

To determine the rate of agreement between the Organ Procurement and Transplant Network (OPTN) and Liver Imaging Reporting and Data System (LI-RADS) classifications for hypervascular liver nodules at least 1 cm in diameter, and for patient eligibility for hepatocellular/MELD (Model for Endstage Liver Disease) exception points.This retrospective study was approved by our Institutional Review Board and was compliant with the Health Insurance Portability and Accountability Act. The requirement for informed consent was waived. This study included 200 hypervascular hepatocellular nodules at least 1 cm in diameter on computed tomography (CT) or magnetic resonance imaging (MRI) examinations in 105 patients with chronic liver disease. Three radiologists blinded to clinical data independently evaluated nodule characteristics, including washout, capsule, size, and size on prior examination. Based on those characteristics, nodules were automatically classified as definite hepatocellular carcinoma (HCC) or not definite HCC using both the OPTN and LI-RADS classifications. Using these classifications and the Milan criteria, each examination was determined to be "below transplant criteria," "within transplant criteria," or "beyond transplant criteria." Agreement was assessed between readers and classification systems, using Fleiss' kappa, intraclass correlation coefficients (ICCs), and simple proportions.Interreader agreement was moderate for nodule features (κ = 0.59-0.69) and nodule classification (0.66-0.69). The two systems were in nearly complete agreement on nodule category assignment (98.7% [592/600]) and patient eligibility for transplant exemption priority (99.4% [313/315]). A few discrepancies occurred for the nodule feature of growth (1.3% [8/600]) and for nodule category assignment (1.3% [8/600]).Agreement between the OPTN and LI-RADS classifications is very strong for categorization of hypervascular liver nodules at least 1 cm in diameter, and for patient eligibility for hepatocellular/MELD exception points. Interreader variability is much higher than intersystem variability.

Authors
Bashir, MR; Huang, R; Mayes, N; Marin, D; Berg, CL; Nelson, RC; Jaffe, TA
MLA Citation
Bashir, MR, Huang, R, Mayes, N, Marin, D, Berg, CL, Nelson, RC, and Jaffe, TA. "Concordance of hypervascular liver nodule characterization between the organ procurement and transplant network and liver imaging reporting and data system classifications." Journal of magnetic resonance imaging : JMRI 42.2 (August 2015): 305-314.
PMID
25371354
Source
epmc
Published In
Journal of Magnetic Resonance Imaging
Volume
42
Issue
2
Publish Date
2015
Start Page
305
End Page
314
DOI
10.1002/jmri.24793

T2-weighted four dimensional magnetic resonance imaging with result-driven phase sorting.

T2-weighted MRI provides excellent tumor-to-tissue contrast for target volume delineation in radiation therapy treatment planning. This study aims at developing a novel T2-weighted retrospective four dimensional magnetic resonance imaging (4D-MRI) phase sorting technique for imaging organ/tumor respiratory motion.A 2D fast T2-weighted half-Fourier acquisition single-shot turbo spin-echo MR sequence was used for image acquisition of 4D-MRI, with a frame rate of 2-3 frames/s. Respiratory motion was measured using an external breathing monitoring device. A phase sorting method was developed to sort the images by their corresponding respiratory phases. Besides, a result-driven strategy was applied to effectively utilize redundant images in the case when multiple images were allocated to a bin. This strategy, selecting the image with minimal amplitude error, will generate the most representative 4D-MRI. Since we are using a different image acquisition mode for 4D imaging (the sequential image acquisition scheme) with the conventionally used cine or helical image acquisition scheme, the 4D dataset sufficient condition was not obviously and directly predictable. An important challenge of the proposed technique was to determine the number of repeated scans (NR) required to obtain sufficient phase information at each slice position. To tackle this challenge, the authors first conducted computer simulations using real-time position management respiratory signals of the 29 cancer patients under an IRB-approved retrospective study to derive the relationships between NR and the following factors: number of slices (NS), number of 4D-MRI respiratory bins (NB), and starting phase at image acquisition (P0). To validate the authors' technique, 4D-MRI acquisition and reconstruction were simulated on a 4D digital extended cardiac-torso (XCAT) human phantom using simulation derived parameters. Twelve healthy volunteers were involved in an IRB-approved study to investigate the feasibility of this technique.4D data acquisition completeness (Cp) increases as NR increases in an inverse-exponential fashion (Cp = 100 - 99 × exp(-0.18 × NR), when NB = 6, fitted using 29 patients' data). The NR required for 4D-MRI reconstruction (defined as achieving 95% completeness, Cp = 95%, NR = NR,95) is proportional to NB (NR,95 ∼ 2.86 × NB, r = 1.0), but independent of NS and P0. Simulated XCAT 4D-MRI showed a clear pattern of respiratory motion. Tumor motion trajectories measured on 4D-MRI were comparable to the average input signal, with a mean relative amplitude error of 2.7% ± 2.9%. Reconstructed 4D-MRI for healthy volunteers illustrated clear respiratory motion on three orthogonal planes, with minimal image artifacts. The artifacts were presumably caused by breathing irregularity and incompleteness of data acquisition (95% acquired only). The mean relative amplitude error between critical structure trajectory and average breathing curve for 12 healthy volunteers is 2.5 ± 0.3 mm in superior-inferior direction.A novel T2-weighted retrospective phase sorting 4D-MRI technique has been developed and successfully applied on digital phantom and healthy volunteers.

Authors
Liu, Y; Yin, F-F; Czito, BG; Bashir, MR; Cai, J
MLA Citation
Liu, Y, Yin, F-F, Czito, BG, Bashir, MR, and Cai, J. "T2-weighted four dimensional magnetic resonance imaging with result-driven phase sorting." Medical physics 42.8 (August 2015): 4460-4471.
PMID
26233176
Source
epmc
Published In
Medical physics
Volume
42
Issue
8
Publish Date
2015
Start Page
4460
End Page
4471
DOI
10.1118/1.4923168

Graft Kidney Torsion After Simultaneous Kidney-Pancreas Transplant: Report of 2 Cases and Literature Review.

Torsion of an allograft kidney is an extremely rare and potentially reversible complication. Imaging diagnosis plays a crucial role because of the absence of specific clinical features. We report 2 cases in which kidney torsion after simultaneous kidney-pancreas transplant was diagnosed by ferumoxytol-enhanced magnetic resonance imaging/angiography and present a review of the relevant literature. Radiologists and clinicians should be aware of this entity because graft salvage depends on rapid diagnosis and surgical detorsion.

Authors
Sofue, K; Vikraman, DS; Jaffe, TA; Chaubal, GN; Bashir, MR
MLA Citation
Sofue, K, Vikraman, DS, Jaffe, TA, Chaubal, GN, and Bashir, MR. "Graft Kidney Torsion After Simultaneous Kidney-Pancreas Transplant: Report of 2 Cases and Literature Review." J Comput Assist Tomogr 39.4 (July 2015): 506-509. (Review)
PMID
25853775
Source
pubmed
Published In
Journal of Computer Assisted Tomography
Volume
39
Issue
4
Publish Date
2015
Start Page
506
End Page
509
DOI
10.1097/RCT.0000000000000250

Image-guided percutaneous drainage vs. surgical repair of gastrointestinal anastomotic leaks: is there a difference in hospital course or hospitalization cost?

To identify differences in hospital course and hospitalization cost when comparing image-guided percutaneous drainage with surgical repair for gastrointestinal anastomotic leaks.A retrospective IRB-approved search using key words "leak" and/or "anastomotic" was performed on all adult CT reports from 2002 to 2011. CT examinations were reviewed for evidence of a postoperative gastrointestinal leak and assigned a confidence score of 1-5 (1 = no leak, 5 = definite leak). Patients with an average confidence score <4 were excluded. Type of surgery, patient data, method of leak management, number of hospital admissions, length of hospital stay, discharge disposition, number of CT examinations, number of drains, and hospitalization costs were collected.One hundred thirty-nine patients had radiographic evidence of a gastrointestinal anastomotic leak (esophageal, gastric, small bowel or colonic). Nine patients were excluded due to low confidence scores. Twenty-seven patients underwent surgical repair (Group A) and 103 were managed entirely with percutaneous image-guided drainage (Group B). There was no significant difference in patient demographics or number of hospital admissions. Patients in Group A had longer median hospital stays compared to Group B (48 vs. 32 days, p = 0.007). The median total hospitalization cost for Group A was more than twice that for Group B ($99,995 vs. $47,838, p = 0.001). Differences in hospital disposition, number of CT examinations, number of drains, and time between original surgery and first CT examination were statistically significant.Gastrointestinal anastomotic leaks managed by percutaneous drainage are associated with lower hospital cost and shorter hospital stays compared with surgical management.

Authors
Burke, LMB; Bashir, MR; Gardner, CS; Parsee, AA; Marin, D; Vermess, D; Bhattacharya, SD; Thacker, JK; Jaffe, TA
MLA Citation
Burke, LMB, Bashir, MR, Gardner, CS, Parsee, AA, Marin, D, Vermess, D, Bhattacharya, SD, Thacker, JK, and Jaffe, TA. "Image-guided percutaneous drainage vs. surgical repair of gastrointestinal anastomotic leaks: is there a difference in hospital course or hospitalization cost?." Abdominal imaging 40.5 (June 2015): 1279-1284.
PMID
25294007
Source
epmc
Published In
Abdominal Imaging
Volume
40
Issue
5
Publish Date
2015
Start Page
1279
End Page
1284
DOI
10.1007/s00261-014-0265-z

Computer-aided liver volumetry: performance of a fully-automated, prototype post-processing solution for whole-organ and lobar segmentation based on MDCT imaging.

To evaluate the performance of a prototype, fully-automated post-processing solution for whole-liver and lobar segmentation based on MDCT datasets.A polymer liver phantom was used to assess accuracy of post-processing applications comparing phantom volumes determined via Archimedes' principle with MDCT segmented datasets. For the IRB-approved, HIPAA-compliant study, 25 patients were enrolled. Volumetry performance compared the manual approach with the automated prototype, assessing intraobserver variability, and interclass correlation for whole-organ and lobar segmentation using ANOVA comparison. Fidelity of segmentation was evaluated qualitatively.Phantom volume was 1581.0 ± 44.7 mL, manually segmented datasets estimated 1628.0 ± 47.8 mL, representing a mean overestimation of 3.0%, automatically segmented datasets estimated 1601.9 ± 0 mL, representing a mean overestimation of 1.3%. Whole-liver and segmental volumetry demonstrated no significant intraobserver variability for neither manual nor automated measurements. For whole-liver volumetry, automated measurement repetitions resulted in identical values; reproducible whole-organ volumetry was also achieved with manual segmentation, p(ANOVA) 0.98. For lobar volumetry, automated segmentation improved reproducibility over manual approach, without significant measurement differences for either methodology, p(ANOVA) 0.95-0.99. Whole-organ and lobar segmentation results from manual and automated segmentation showed no significant differences, p(ANOVA) 0.96-1.00. Assessment of segmentation fidelity found that segments I-IV/VI showed greater segmentation inaccuracies compared to the remaining right hepatic lobe segments.Automated whole-liver segmentation showed non-inferiority of fully-automated whole-liver segmentation compared to manual approaches with improved reproducibility and post-processing duration; automated dual-seed lobar segmentation showed slight tendencies for underestimating the right hepatic lobe volume and greater variability in edge detection for the left hepatic lobe compared to manual segmentation.

Authors
Fananapazir, G; Bashir, MR; Marin, D; Boll, DT
MLA Citation
Fananapazir, G, Bashir, MR, Marin, D, and Boll, DT. "Computer-aided liver volumetry: performance of a fully-automated, prototype post-processing solution for whole-organ and lobar segmentation based on MDCT imaging." Abdominal imaging 40.5 (June 2015): 1203-1212.
PMID
25326261
Source
epmc
Published In
Abdominal Imaging
Volume
40
Issue
5
Publish Date
2015
Start Page
1203
End Page
1212
DOI
10.1007/s00261-014-0276-9

TH-CD-207-09: Retrospective 4D-MRI with a Novel Image-Based Surrogate: A Sagittal-Coronal-Diaphragm Point of Intersection (SCD-PoI) Motion Tracking Method.

PURPOSE: The unreliable stability of internal respiratory surrogates and inconvenience of external respiratory surrogates for current retrospective 4D-MRI techniques largely affects the image quality of 4D-MRI. This study aims at developing image-based surrogate, a sagittal-coronal-diaphragm point of intersection (SCD-PoI) motion tracking method for retrospective 4D-MRI reconstruction. METHODS/MATERIALS: As a pre-estimate of respiratory motion pattern, single-slice sagittal cines (FIESTA) were acquired at a location near the dome of the diaphragm. Subsequently, multi-slice coronal cines (FIESTA) were acquired and used for 4D-MRI reconstruction with phase sorting. Diaphragm motion trajectories were measured from the point of intersection between sagittal MRI cine plane, coronal MRI cine plain and the diaphragm dome surface. This point is defined as sagittal-coronal-diaphragm point of intersection (SCD-PoI). We pre-estimate respiraotyr motion by tracking SCD-PoI on sagitall cine. Then coronal images were then re-binned to different phased bins according to SCD-PoI motion tracking on coronal cine. This 4D-MRI technique was evaluated on a 4D Digital Extended Cardiac-Torso (XCAT) human phantom with a hypothesized moving tumor, six healthy voluneteers and two cancer patients under an IRB-approved study. Region of interest (ROI: tumor for XCAT and patients, dome of left kidney for healthy volunteers) trajectories on 4D-MRI were measured and compared with the reference (input respiratory curve for XCAT and ROI trajectories extracted from reference single-slice MRI cine (FIESTA) for human subjects). Superior-inferior (SI) mean absolute amplitude difference (D) and cross-correlation coefficient (CC) were calculated. RESULTS: 4D-MRI on XCAT demonstrated highly accurate motion information with a low D (1.13mm) and a high CC (0.98) in the SI direction. Minimal artifacts were observed in human participants' 4D-MRI, and images were adequate to reveal the respiratory motion of organs and tumor (D=1.08±1.03mm; CC=0.96). CONCLUSION: A novel 4D-MRI technique with image-based respiratory surrogate has been developed and tested on a digital phantom and human subjects.

Authors
Liu, Y; Yin, F; Czito, B; Bashir, M; Palta, M; Cai, J
MLA Citation
Liu, Y, Yin, F, Czito, B, Bashir, M, Palta, M, and Cai, J. "TH-CD-207-09: Retrospective 4D-MRI with a Novel Image-Based Surrogate: A Sagittal-Coronal-Diaphragm Point of Intersection (SCD-PoI) Motion Tracking Method." Medical physics 42.6 (June 2015): 3736-.
PMID
26129566
Source
epmc
Published In
Medical physics
Volume
42
Issue
6
Publish Date
2015
Start Page
3736
DOI
10.1118/1.4926267

SU-F-303-13: Initial Evaluation of Four Dimensional Diffusion- Weighted MRI (4D-DWI) and Its Effect On Apparent Diffusion Coefficient (ADC) Measurement.

PURPOSE: Diffusion-weighted imaging(DWI) has been shown to have superior tumor-to-tissue contrast for cancer detection.This study aims at developing and evaluating a four dimensional DWI(4D-DWI) technique using retrospective sorting method for imaging respiratory motion for radiotherapy planning,and evaluate its effect on Apparent Diffusion Coefficient(ADC) measurement. MATERIALS/METHODS: Image acquisition was performed by repeatedly imaging a volume of interest using a multi-slice single-shot 2D-DWI sequence in the axial planes and cine MRI(served as reference) using FIESTA sequence.Each 2D-DWI image were acquired in xyz-diffusion-directions with a high b-value(b=500s/mm2).The respiratory motion was simultaneously recorded using bellows.Retrospective sorting was applied in each direction to reconstruct 4D-DWI.The technique was evaluated using a computer simulated 4D-digital human phantom(XCAT),a motion phantom and a healthy volunteer under an IRB-approved study.Motion trajectories of regions-of-interests(ROI) were extracted from 4D-DWI and compared with reference.The mean motion trajectory amplitude differences(D) between the two was calculated.To quantitatively analyze the motion artifacts,XCAT were controlled to simulate regular motion and the motions of 10 liver cancer patients.4D-DWI,free-breathing DWI(FB- DWI) were reconstructed.Tumor volume difference(VD) of each phase of 4D-DWI and FB-DWI from the input static tumor were calculated.Furthermore, ADC was measured for each phase of 4D-DWI and FB-DWI data,and mean tumor ADC values(M-ADC) were calculated.Mean M-ADC over all 4D-DWI phases was compared with M-ADC calculated from FB-DWI. RESULTS: 4D-DWI of XCAT,the motion phantom and the healthy volunteer demonstrated the respiratory motion clearly.ROI D values were 1.9mm,1.7mm and 2.0mm,respectively.For motion artifacts analysis,XCAT 4D-DWI images show much less motion artifacts compare to FB-DWI.Mean VD for 4D-WDI and FB-DWI were 8.5±1.4% and 108±15%,respectively.Mean M-ADC for ADC measured from 4D-DWI and M-ADC measured from FB-DWI were (2.29±0.04)*0.001*mm2/s and (3.80±0.01)*0.001*mm2/s,respectively.ADC value ground-truth is 2.24*0.001*mm2/s from the input of the simulation. CONCLUSION: A respiratory correlated 4D-DWI technique has been initially evaluated in phantoms and a human subject.Comparing to free breathing DWI,4D-DWI can lead to more accurate measurement of ADC.

Authors
Liu, Y; Yin, F; Czito, B; Bashir, M; Palta, M; Zhong, X; Dale, B; Cai, J
MLA Citation
Liu, Y, Yin, F, Czito, B, Bashir, M, Palta, M, Zhong, X, Dale, B, and Cai, J. "SU-F-303-13: Initial Evaluation of Four Dimensional Diffusion- Weighted MRI (4D-DWI) and Its Effect On Apparent Diffusion Coefficient (ADC) Measurement." Medical physics 42.6 (June 2015): 3540-.
PMID
26128539
Source
epmc
Published In
Medical physics
Volume
42
Issue
6
Publish Date
2015
Start Page
3540
DOI
10.1118/1.4925240

Initial Evaluation of Four Dimensional Diffusion-Weighted MRI (4D-DWI) and Its Effect On Apparent Diffusion Coefficient (ADC) Measurement

Authors
Liu, Y; Yin, F; Czito, B; Bashir, M; Palta, M; Zhong, X; Dale, B; Cai, J
MLA Citation
Liu, Y, Yin, F, Czito, B, Bashir, M, Palta, M, Zhong, X, Dale, B, and Cai, J. "Initial Evaluation of Four Dimensional Diffusion-Weighted MRI (4D-DWI) and Its Effect On Apparent Diffusion Coefficient (ADC) Measurement." June 2015.
Source
wos-lite
Published In
Medical physics
Volume
42
Issue
6
Publish Date
2015
Start Page
3540
End Page
3540

Retrospective 4D-MRI with a Novel Image-Based Surrogate: A Sagittal-Coronal-Diaphragm Point of Intersection (SCD-PoI) Motion Tracking Method

Authors
Liu, Y; Yin, F; Czito, B; Bashir, M; Palta, M; Cai, I
MLA Citation
Liu, Y, Yin, F, Czito, B, Bashir, M, Palta, M, and Cai, I. "Retrospective 4D-MRI with a Novel Image-Based Surrogate: A Sagittal-Coronal-Diaphragm Point of Intersection (SCD-PoI) Motion Tracking Method." June 2015.
Source
wos-lite
Published In
Medical physics
Volume
42
Issue
6
Publish Date
2015
Start Page
3736
End Page
3736

Endemic vitamin D deficiency, impact on incidence and prevalence of Parkinson's disease

Authors
Bajwa, JA; Nahrir, S; Muhammad, TM; Bashir, MS; Mujtaba, A; Siddiqui, R
MLA Citation
Bajwa, JA, Nahrir, S, Muhammad, TM, Bashir, MS, Mujtaba, A, and Siddiqui, R. "Endemic vitamin D deficiency, impact on incidence and prevalence of Parkinson's disease." June 2015.
Source
wos-lite
Published In
Movement Disorders
Volume
30
Publish Date
2015
Start Page
S30
End Page
S31

Gender differences in health care disease burden severity among caregivers of Parkinson's disease patients in an Arab cohort

Authors
Seddeq, YA; Al-Shammari, NH; Mohammad, TM; Bashir, MS; Bajwa, JA
MLA Citation
Seddeq, YA, Al-Shammari, NH, Mohammad, TM, Bashir, MS, and Bajwa, JA. "Gender differences in health care disease burden severity among caregivers of Parkinson's disease patients in an Arab cohort." June 2015.
Source
wos-lite
Published In
Movement Disorders
Volume
30
Publish Date
2015
Start Page
S546
End Page
S546

Characterize sleep related disorders in subtypes of Parkinson's disease

Authors
Hanif, S; Bashir, MS; Muhammad, TM; Bajwa, JA
MLA Citation
Hanif, S, Bashir, MS, Muhammad, TM, and Bajwa, JA. "Characterize sleep related disorders in subtypes of Parkinson's disease." June 2015.
Source
wos-lite
Published In
Movement Disorders
Volume
30
Publish Date
2015
Start Page
S159
End Page
S159

Effect of anisotropic dust pressure and superthermal electrons on propagation and stability of dust acoustic solitary waves

Authors
Bashir, MF; Behery, EE; El-Taibany, WF
MLA Citation
Bashir, MF, Behery, EE, and El-Taibany, WF. "Effect of anisotropic dust pressure and superthermal electrons on propagation and stability of dust acoustic solitary waves." Physics of Plasmas 22.6 (June 2015): 062112-062112.
Source
crossref
Published In
Physics of Plasmas
Volume
22
Issue
6
Publish Date
2015
Start Page
062112
End Page
062112
DOI
10.1063/1.4922750

Fe<inf>3</inf>O<inf>4</inf> stabilized zirconia: structural, mechanical and optical properties

© 2014, Springer Science+Business Media New York.Zirconia (ZrO2) is one of the most well studied transition-metal oxides in the optical and biological fields. The applications area of ZrO2 can be increased by addition of metal oxides. Aim of this study is to determine the effect of acidic and basic Fe3O4 nanoparticles’ (NPs) doping in sol–gel synthesized ZrO2. Different samples are prepared by varying Fe3O4 concentrations, acidic and basic, in the range of 2–10 wt%. Sols of Fe3O4 doped ZrO2 (FOZ) are spin coated onto glass substrates at 3000 rpm for 30 s. FOZ films are annealed at 300 °C for 1 h. It is worth mentioning that Fe3O4 nanoparticles (acidic and basic) are used for the first time, to the best of our knowledge, to stabilize zirconia using sol–gel technique. Moreover, completely homogenous FOZ sol is obtained using water as a solvent. X-ray diffraction results confirm the formation of phase pure tetragonal ZrO2 (t-ZrO2) along with less intense peak of Fe3O4 at 8–10 wt% of basic dopant. Optical spectra reveal that energy band gap lies in the range of 4.8 to 5.0 eV whereas, high value of transmission up to 80 % has been observed in case of basic dopant. Refractive indices vary with the variation in crystal structure and density of the films. Redshift is observed in Fe3O4 doped zirconia. Hardness of the samples is in the range of 310 to 962 HV.

Authors
Bashir, M; Riaz, S; Naseem, S
MLA Citation
Bashir, M, Riaz, S, and Naseem, S. "Fe<inf>3</inf>O<inf>4</inf> stabilized zirconia: structural, mechanical and optical properties." May 1, 2015.
Source
scopus
Published In
Journal of Sol-Gel Science and Technology
Volume
74
Issue
2
Publish Date
2015
Start Page
281
End Page
289
DOI
10.1007/s10971-014-3415-4

Correlation between quantitative whole-body muscle magnetic resonance imaging and clinical muscle weakness in Pompe disease.

INTRODUCTION: Previous examination of whole-body muscle involvement in Pompe disease has been limited to physical examination and/or qualitative magnetic resonance imaging (MRI). In this study we assess the feasibility of quantitative proton-density fat-fraction (PDFF) whole-body MRI in late-onset Pompe disease (LOPD) and compare the results with manual muscle testing. METHODS: Seven LOPD patients and 11 disease-free controls underwent whole-body PDFF MRI. Quantitative MR muscle group assessments were compared with physical testing of muscle groups. RESULTS: The 95% upper limits of confidence intervals for muscle groups were 4.9-12.6% in controls and 6.8-76.4% in LOPD patients. LOPD patients showed severe and consistent tongue and axial muscle group involvement, with less marked involvement of peripheral musculature. MRI was more sensitive than physical examination for detection of abnormality in multiple muscle groups. CONCLUSION: This integrated, quantitative approach to muscle assessment provides more detailed data than physical examination and may have clinical utility for monitoring disease progression and treatment response.

Authors
Horvath, JJ; Austin, SL; Case, LE; Greene, KB; Jones, HN; Soher, BJ; Kishnani, PS; Bashir, MR
MLA Citation
Horvath, JJ, Austin, SL, Case, LE, Greene, KB, Jones, HN, Soher, BJ, Kishnani, PS, and Bashir, MR. "Correlation between quantitative whole-body muscle magnetic resonance imaging and clinical muscle weakness in Pompe disease." Muscle & nerve 51.5 (May 2015): 722-730.
PMID
25155446
Source
epmc
Published In
Muscle and Nerve
Volume
51
Issue
5
Publish Date
2015
Start Page
722
End Page
730
DOI
10.1002/mus.24437

On confirmation bias in imaging research.

Authors
Bashir, MR; Sirlin, CB; Reeder, SB
MLA Citation
Bashir, MR, Sirlin, CB, and Reeder, SB. "On confirmation bias in imaging research." Journal of magnetic resonance imaging : JMRI 41.5 (May 2015): 1163-1164.
PMID
25124454
Source
epmc
Published In
Journal of Magnetic Resonance Imaging
Volume
41
Issue
5
Publish Date
2015
Start Page
1163
End Page
1164
DOI
10.1002/jmri.24720

Advanced magnetic resonance techniques: 3 T.

Magnetic resonance (MR) imaging at 3 T is clinically feasible and, in the right context, can provide improvements compared with 1.5-T MR imaging. Improvements in both signal/noise ratio and contrast/noise ratio can be used to improve image homogeneity and/or spatial and temporal resolution. Some techniques, such as brain functional MR imaging, are considered far superior at 3 T than at 1.5 T. Although several challenges still exist, 3 T has been become well established in clinical MR imaging.

Authors
Bhatti, L; Hoang, JK; Dale, BM; Bashir, MR
MLA Citation
Bhatti, L, Hoang, JK, Dale, BM, and Bashir, MR. "Advanced magnetic resonance techniques: 3 T." Radiologic clinics of North America 53.3 (May 2015): 441-455.
PMID
25953283
Source
epmc
Published In
Radiologic Clinics of North America
Volume
53
Issue
3
Publish Date
2015
Start Page
441
End Page
455
DOI
10.1016/j.rcl.2014.12.001

Trust in automation: integrating empirical evidence on factors that influence trust.

OBJECTIVE: We systematically review recent empirical research on factors that influence trust in automation to present a three-layered trust model that synthesizes existing knowledge. BACKGROUND: Much of the existing research on factors that guide human-automation interaction is centered around trust, a variable that often determines the willingness of human operators to rely on automation. Studies have utilized a variety of different automated systems in diverse experimental paradigms to identify factors that impact operators' trust. METHOD: We performed a systematic review of empirical research on trust in automation from January 2002 to June 2013. Papers were deemed eligible only if they reported the results of a human-subjects experiment in which humans interacted with an automated system in order to achieve a goal. Additionally, a relationship between trust (or a trust-related behavior) and another variable had to be measured. All together, 101 total papers, containing 127 eligible studies, were included in the review. RESULTS: Our analysis revealed three layers of variability in human-automation trust (dispositional trust, situational trust, and learned trust), which we organize into a model. We propose design recommendations for creating trustworthy automation and identify environmental conditions that can affect the strength of the relationship between trust and reliance. Future research directions are also discussed for each layer of trust. CONCLUSION: Our three-layered trust model provides a new lens for conceptualizing the variability of trust in automation. Its structure can be applied to help guide future research and develop training interventions and design procedures that encourage appropriate trust.

Authors
Hoff, KA; Bashir, M
MLA Citation
Hoff, KA, and Bashir, M. "Trust in automation: integrating empirical evidence on factors that influence trust." Human factors 57.3 (May 2015): 407-434.
PMID
25875432
Source
epmc
Published In
Human Factors
Volume
57
Issue
3
Publish Date
2015
Start Page
407
End Page
434
DOI
10.1177/0018720814547570

Effects of the organic additives on dental zirconia ceramics: structural and mechanical properties

Authors
Bashir, M; Riaz, S; Kayani, ZN; Naseem, S
MLA Citation
Bashir, M, Riaz, S, Kayani, ZN, and Naseem, S. "Effects of the organic additives on dental zirconia ceramics: structural and mechanical properties." May 2015.
Source
crossref
Published In
Journal of Sol-Gel Science and Technology
Volume
74
Issue
2
Publish Date
2015
Start Page
290
End Page
298
DOI
10.1007/s10971-014-3447-9

Synthesis of stabilized zirconia hollow nanoparticles: sugar as a template

Authors
Riaz, S; Bashir, M; Naseem, S
MLA Citation
Riaz, S, Bashir, M, and Naseem, S. "Synthesis of stabilized zirconia hollow nanoparticles: sugar as a template." May 2015.
Source
crossref
Published In
Journal of Sol-Gel Science and Technology
Volume
74
Issue
2
Publish Date
2015
Start Page
275
End Page
280
DOI
10.1007/s10971-015-3707-3

Emerging applications for ferumoxytol as a contrast agent in MRI.

Ferumoxytol is an ultrasmall superparamagnetic iron oxide (USPIO) agent initially approved by the Food and Drug Administration (FDA) as an iron replacement therapy for patients with anemia due to chronic renal failure. Recently, ferumoxytol has been investigated extensively as an intravenous contrast agent in magnetic resonance imaging (MRI). Since it causes regional T1 and T2 * shortening in vivo, conventional pulse sequences can be used following ferumoxytol administration to demonstrate signal enhancement or loss. Ferumoxytol can be administered as a rapid bolus and has a long intravascular half-life on the order of 14-15 hours, making it a potentially useful agent for vascular and perfusion-weighted MRI. In comparison to other USPIOs, ferumoxytol is less limited by allergic and idiosyncratic reactions. Furthermore, since ferumoxytol is an iron-based agent with no potential for causing nephrogenic systemic fibrosis, it may be useful as an alternative to gadolinium-based contrast agents in patients with compromised renal function. Ferumoxytol is ultimately taken up by macrophages/the reticuloendothelial system in the liver, spleen, and lymph nodes, and this uptake mechanism is being explored as a novel imaging technique for vascular lesions, tumors, and lymph nodes. This article reviews the properties of ferumoxytol relevant to MRI as well as many of the uses for the agent currently under investigation.

Authors
Bashir, MR; Bhatti, L; Marin, D; Nelson, RC
MLA Citation
Bashir, MR, Bhatti, L, Marin, D, and Nelson, RC. "Emerging applications for ferumoxytol as a contrast agent in MRI." Journal of magnetic resonance imaging : JMRI 41.4 (April 2015): 884-898.
PMID
24974785
Source
epmc
Published In
Journal of Magnetic Resonance Imaging
Volume
41
Issue
4
Publish Date
2015
Start Page
884
End Page
898
DOI
10.1002/jmri.24691

THE MECHANISM OF ACTION OF THE MALE TRANSOBTURATOR SLING IS VIA INCREASED FUNCTIONAL LENGTH OF THE MEMBRANOUS URETHRA: A PROSPECTIVE, CONTROLLED STUDY USING DYNAMIC MRI

Authors
Selph, JP; Bashir, M; Gupta, S; Belsante, MJ; Brand, T; Tausch, T; Lloyd, J; Goldsmith, Z; Peterson, A
MLA Citation
Selph, JP, Bashir, M, Gupta, S, Belsante, MJ, Brand, T, Tausch, T, Lloyd, J, Goldsmith, Z, and Peterson, A. "THE MECHANISM OF ACTION OF THE MALE TRANSOBTURATOR SLING IS VIA INCREASED FUNCTIONAL LENGTH OF THE MEMBRANOUS URETHRA: A PROSPECTIVE, CONTROLLED STUDY USING DYNAMIC MRI." April 2015.
Source
wos-lite
Published In
The Journal of Urology
Volume
193
Issue
4
Publish Date
2015
Start Page
E1094
End Page
E1094

Interdependencies of acquisition, detection, and reconstruction techniques on the accuracy of iodine quantification in varying patient sizes employing dual-energy CT.

PURPOSE: To assess the impact of patient habitus, acquisition parameters, detector efficiencies, and reconstruction techniques on the accuracy of iodine quantification using dual-source dual-energy CT (DECT). MATERIALS AND METHODS: Two phantoms simulating small and large patients contained 20 iodine solutions mimicking vascular and parenchymal enhancement from saline isodensity to 400 HU and 30 iodine solutions simulating enhancement of the urinary collecting system from 400 to 2,000 HU. DECT acquisition (80/140 kVp and 100/140 kVp) was performed using two DECT systems equipped with standard and integrated electronics detector technologies. DECT raw datasets were reconstructed using filtered backprojection (FBP), and iterative reconstruction (SAFIRE I/V). RESULTS: Accuracy for iodine quantification was significantly higher for the small compared to the large phantoms (9.2 % ± 7.5 vs. 24.3 % ± 26.1, P = 0.0001), the integrated compared to the conventional detectors (14.8 % ± 20.6 vs. 18.8 % ± 20.4, respectively; P = 0.006), and SAFIRE V compared to SAFIRE I and FBP reconstructions (15.2 % ± 18.1 vs. 16.1 % ± 17.6 and 18.9 % ± 20.4, respectively; P ≤ 0.003). A significant synergism was observed when the most effective detector and reconstruction techniques were combined with habitus-adapted dual-energy pairs. CONCLUSION: In a second-generation dual-source DECT system, the accuracy of iodine quantification can be substantially improved by an optimal choice and combination of acquisition parameters, detector, and reconstruction techniques.

Authors
Marin, D; Pratts-Emanuelli, JJ; Mileto, A; Husarik, DB; Bashir, MR; Nelson, RC; Boll, DT
MLA Citation
Marin, D, Pratts-Emanuelli, JJ, Mileto, A, Husarik, DB, Bashir, MR, Nelson, RC, and Boll, DT. "Interdependencies of acquisition, detection, and reconstruction techniques on the accuracy of iodine quantification in varying patient sizes employing dual-energy CT." European radiology 25.3 (March 2015): 679-686.
PMID
25278247
Source
epmc
Published In
European Radiology
Volume
25
Issue
3
Publish Date
2015
Start Page
679
End Page
686
DOI
10.1007/s00330-014-3447-8

Diagnostic per-patient accuracy of an abbreviated hepatobiliary phase gadoxetic acid-enhanced MRI for hepatocellular carcinoma surveillance.

OBJECTIVE. The purpose of this study is to evaluate the per-patient diagnostic performance of an abbreviated gadoxetic acid-enhanced MRI protocol for hepatocellular carcinoma (HCC) surveillance. MATERIALS AND METHODS. A retrospective review identified 298 consecutive patients at risk for HCC enrolled in a gadoxetic acid-enhanced MRI-based HCC surveillance program. For each patient, the first gadoxetic acid-enhanced MRI was analyzed. To simulate an abbreviated protocol, two readers independently read two image sets per patient: set 1 consisted of T1-weighted 20-minute hepatobiliary phase and T2-weighted single-shot fast spin-echo (SSFSE) images; set 2 included diffusion-weighted imaging (DWI) and images from set 1. Image sets were scored as positive or negative according to the presence of at least one nodule 10 mm or larger that met the predetermined criteria. Agreement was assessed using Cohen kappa statistics. A composite reference standard was used to determine the diagnostic performance of each image set for each reader. RESULTS. Interreader agreement was substantial for both image sets (κ = 0.72 for both) and intrareader agreement was excellent (κ = 0.97-0.99). Reader performance for image set 1 was sensitivity of 85.7% for reader A and 79.6% for reader B, specificity of 91.2% for reader A and 95.2% for reader B, and negative predictive value of 97.0% for reader A and 96.0% for reader B. Reader performance for image set 2 was nearly identical, with only one of 298 examinations scored differently on image set 2 compared with set 1. CONCLUSION. An abbreviated MRI protocol consisting of T2-weighted SSFSE and gadoxetic acid-enhanced hepatobiliary phase has high negative predictive value and may be an acceptable method for HCC surveillance. The inclusion of a DWI sequence did not significantly alter the diagnostic performance of the abbreviated protocol.

Authors
Marks, RM; Ryan, A; Heba, ER; Tang, A; Wolfson, TJ; Gamst, AC; Sirlin, CB; Bashir, MR
MLA Citation
Marks, RM, Ryan, A, Heba, ER, Tang, A, Wolfson, TJ, Gamst, AC, Sirlin, CB, and Bashir, MR. "Diagnostic per-patient accuracy of an abbreviated hepatobiliary phase gadoxetic acid-enhanced MRI for hepatocellular carcinoma surveillance." AJR. American journal of roentgenology 204.3 (March 2015): 527-535.
PMID
25714281
Source
epmc
Published In
AJR. American journal of roentgenology
Volume
204
Issue
3
Publish Date
2015
Start Page
527
End Page
535
DOI
10.2214/ajr.14.12986

Quantification of hepatic steatosis with a multistep adaptive fitting MRI approach: prospective validation against MR spectroscopy.

OBJECTIVE. The purpose of this study is to prospectively compare hybrid and complex chemical shift-based MRI fat quantification methods against MR spectroscopy (MRS) for the measurement of hepatic steatosis. SUBJECTS AND METHODS. Forty-two subjects (18 men and 24 women; mean ± SD age, 52.8 ± 14 years) were prospectively enrolled and imaged at 3 T with a chemical shift-based MRI sequence and a single-voxel MRS sequence, each in one breath-hold. Proton density fat fraction and rate constant (R2*) using both single- and dual-R2* hybrid fitting methods, as well as proton density fat fraction and R2* maps using a complex fitting method, were generated. A single radiologist colocalized volumes of interest on the proton density fat fraction and R2* maps according to the spectroscopy measurement voxel. Agreement among the three MRI methods and the MRS proton density fat fraction values was assessed using linear regression, intraclass correlation coefficient (ICC), and Bland-Altman analysis. RESULTS. Correlation between the MRI and MRS measures of proton density fat fraction was excellent. Linear regression coefficients ranged from 0.98 to 1.01, and intercepts ranged from -1.12% to 0.49%. Agreement measured by ICC was also excellent (0.99 for all three methods). Bland-Altman analysis showed excellent agreement, with mean differences of -1.0% to 0.6% (SD, 1.3-1.6%). CONCLUSION. The described MRI-based liver proton density fat fraction measures are clinically feasible and accurate. The validation of proton density fat fraction quantification methods is an important step toward wide availability and acceptance of the MRI-based measurement of proton density fat fraction as an accurate and generalizable biomarker.

Authors
Bashir, MR; Zhong, X; Nickel, MD; Fananapazir, G; Kannengiesser, SAR; Kiefer, B; Dale, BM
MLA Citation
Bashir, MR, Zhong, X, Nickel, MD, Fananapazir, G, Kannengiesser, SAR, Kiefer, B, and Dale, BM. "Quantification of hepatic steatosis with a multistep adaptive fitting MRI approach: prospective validation against MR spectroscopy." AJR. American journal of roentgenology 204.2 (February 2015): 297-306.
PMID
25615751
Source
epmc
Published In
AJR. American journal of roentgenology
Volume
204
Issue
2
Publish Date
2015
Start Page
297
End Page
306
DOI
10.2214/ajr.14.12457

Respiratory-gated noncontrast SPACE MR angiography sequence at 3T for evaluation of the central veins of the chest: A feasibility study

© 2013 Wiley Periodicals, Inc. 125.Purpose: To evaluate the feasibility of a respiratorygated noncontrast magnetic resonance angiography (MRA) sequence for imaging the central veins of the chest.Materials and Methods: Eleven healthy subjects underwent MRA of the central veins of the chest with a respiratory-gated noncontrast (SPACE) sequence. Qualitative visualization and signal homogeneity of each central venous segment were scored by two radiologists on a scale of 1-4. Signal-to-noise and contrast-to-noise ratios (SNR and CNR) were also calculated. Retrospective review of our imaging database revealed 13 patients with suspected pathology of the central veins who underwent a clinical MRA examination using the SPACE sequence as well as reference standard central venous imaging with contrast-enhanced MRA or conventional venography.Results: In healthy subjects, all central venous segments demonstrated good to excellent venous visualization and homogeneity scores with the noncontrast SPACE sequence. The mean SNR and CNR of the central venous system were 192.7 and 175.0, respectively. In the 13 clinical examinations, the sensitivity and specificity for detection of stenosis or occlusions was 100% and 100% for reader 1 and 95% and 91% for reader 2, respectively.Conclusion: The respiratory-gated noncontrast SPACE sequence provided excellent imaging characteristics of the central veins in healthy subjects with promising diagnostic accuracy in patients with central venous pathology.

Authors
Kim, CY; Bashir, MR; Heye, T; Dale, BM; Nichols, HL; Merkle, EM
MLA Citation
Kim, CY, Bashir, MR, Heye, T, Dale, BM, Nichols, HL, and Merkle, EM. "Respiratory-gated noncontrast SPACE MR angiography sequence at 3T for evaluation of the central veins of the chest: A feasibility study." Journal of Magnetic Resonance Imaging 41.1 (January 1, 2015): 67-73. (Review)
Source
scopus
Published In
Journal of Magnetic Resonance Imaging
Volume
41
Issue
1
Publish Date
2015
Start Page
67
End Page
73
DOI
10.1002/jmri.24540

Effect of Glomus mosseae (Gerd and Trappe) and neemex® against Meloidogyne incognita (Kofoid and White) chitwood on eggplant

Copyright 2015 Zoological Society of Pakistan.An experiment was conducted to formulate a strategy for the management of root-knot nematode, (Meloidogyne incognita) on eggplant under field conditions by mycorrhizal fungus (Glomus mosseae) and neemex®(Azadirachtin) alone and in combination. Eggplant seedlings were transplanted to micro plot beds and treated with mycorrhizal fungus and neemex alone and together while M. incognita was inoculated after two weeks. Transplants obtained from the micro plot beds, treated with neemex + mycorrhizal fungus were least infected. The infection caused by M. incognita was significantly decreased by combined application of mycorrhizal fungus and neemex while more plant growth and nutrient uptake was recorded. The combined effect of these two components facilitated the sustainable management of M. incognita on eggplant under field conditions.

Authors
Khan, AUR; Javed, N; Khan, SA; Bashir, MH
MLA Citation
Khan, AUR, Javed, N, Khan, SA, and Bashir, MH. "Effect of Glomus mosseae (Gerd and Trappe) and neemex® against Meloidogyne incognita (Kofoid and White) chitwood on eggplant." Pakistan Journal of Zoology 47.3 (January 1, 2015): 679-683.
Source
scopus
Published In
Pakistan journal of zoology
Volume
47
Issue
3
Publish Date
2015
Start Page
679
End Page
683

Respiratory-gated noncontrast SPACE MR angiography sequence at 3T for evaluation of the central veins of the chest: a feasibility study.

PURPOSE: To evaluate the feasibility of a respiratory-gated noncontrast magnetic resonance angiography (MRA) sequence for imaging the central veins of the chest. MATERIALS AND METHODS: Eleven healthy subjects underwent MRA of the central veins of the chest with a respiratory-gated noncontrast (SPACE) sequence. Qualitative visualization and signal homogeneity of each central venous segment were scored by two radiologists on a scale of 1-4. Signal-to-noise and contrast-to-noise ratios (SNR and CNR) were also calculated. Retrospective review of our imaging database revealed 13 patients with suspected pathology of the central veins who underwent a clinical MRA examination using the SPACE sequence as well as reference standard central venous imaging with contrast-enhanced MRA or conventional venography. RESULTS: In healthy subjects, all central venous segments demonstrated good to excellent venous visualization and homogeneity scores with the noncontrast SPACE sequence. The mean SNR and CNR of the central venous system were 192.7 and 175.0, respectively. In the 13 clinical examinations, the sensitivity and specificity for detection of stenosis or occlusions was 100% and 100% for reader 1 and 95% and 91% for reader 2, respectively. CONCLUSION: The respiratory-gated noncontrast SPACE sequence provided excellent imaging characteristics of the central veins in healthy subjects with promising diagnostic accuracy in patients with central venous pathology.

Authors
Kim, CY; Bashir, MR; Heye, T; Dale, BM; Nichols, HL; Merkle, EM
MLA Citation
Kim, CY, Bashir, MR, Heye, T, Dale, BM, Nichols, HL, and Merkle, EM. "Respiratory-gated noncontrast SPACE MR angiography sequence at 3T for evaluation of the central veins of the chest: a feasibility study." J Magn Reson Imaging 41.1 (January 2015): 67-73.
PMID
24343858
Source
pubmed
Published In
Journal of Magnetic Resonance Imaging
Volume
41
Issue
1
Publish Date
2015
Start Page
67
End Page
73
DOI
10.1002/jmri.24540

Respiratory motion artifact affecting hepatic arterial phase MR imaging with gadoxetate disodium is more common in patients with a prior episode of arterial phase motion associated with gadoxetate disodium.

PURPOSE: To determine, in a dual-center setting, whether patients who experience transient severe motion ( TSM transient severe motion ) in the arterial phase during gadoxetate disodium-enhanced magnetic resonance (MR) imaging are at higher risk for a subsequent episode of TSM transient severe motion than patients who do not have TSM transient severe motion during initial gadoxetate disodium administration. MATERIALS AND METHODS: Institutional review board approval was obtained for this retrospective, multi-institutional HIPAA-compliant study. The requirement for informed consent was waived. One hundred seventy patients each underwent two MR imaging examinations with bolus injection of gadoxetate disodium at one of two sites. Three radiologists reviewed the examinations at each site for TSM transient severe motion , based on severe arterial phase motion, despite minimal motion in the other dynamic phases. The occurrence rate of TSM transient severe motion in the second examination was compared between patients who had TSM transient severe motion in their first examination and those who did not by using the χ(2) or Fisher exact test, as appropriate. Relative risks and 95% confidence intervals ( CI confidence interval s) were calculated. RESULTS: TSM transient severe motion rates in second examinations were significantly higher for patients who had TSM transient severe motion in their first examination: site 1, 67% (six of nine) vs 4% (three of 69) (P < .0001); site 2, 60% (three of five) vs 6% (five of 87) (P < .005); and both sites, 64% (nine of 14) vs 5% (eight of 156) (P < .0001). Relative risks were 15 for site 1 (95% CI confidence interval : 5, 51), 10 for site 2 (95% CI confidence interval : 3, 32), and 13 for both sites (95% CI confidence interval : 6, 27). CONCLUSION: Patients who experience TSM transient severe motion during gadoxetate disodium-enhanced MR imaging are at significantly and substantially higher risk for TSM transient severe motion in the next gadoxetate disodium-enhanced examination compared with patients who do not have TSM transient severe motion during their initial gadoxetate disodium administration.

Authors
Bashir, MR; Castelli, P; Davenport, MS; Larson, D; Marin, D; Hussain, HK; Jaffe, TA
MLA Citation
Bashir, MR, Castelli, P, Davenport, MS, Larson, D, Marin, D, Hussain, HK, and Jaffe, TA. "Respiratory motion artifact affecting hepatic arterial phase MR imaging with gadoxetate disodium is more common in patients with a prior episode of arterial phase motion associated with gadoxetate disodium." Radiology 274.1 (January 2015): 141-148.
PMID
25162310
Source
epmc
Published In
Radiology
Volume
274
Issue
1
Publish Date
2015
Start Page
141
End Page
148
DOI
10.1148/radiol.14140386

Emerging applications for ferumoxytol as a contrast agent in MRI

© 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.Ferumoxytol is an ultrasmall superparamagnetic iron oxide (USPIO) agent initially approved by the Food and Drug Administration (FDA) as an iron replacement therapy for patients with anemia due to chronic renal failure. Recently, ferumoxytol has been investigated extensively as an intravenous contrast agent in magnetic resonance imaging (MRI). Since it causes regional T1 and T2∗ shortening in vivo, conventional pulse sequences can be used following ferumoxytol administration to demonstrate signal enhancement or loss. Ferumoxytol can be administered as a rapid bolus and has a long intravascular half-life on the order of 14-15 hours, making it a potentially useful agent for vascular and perfusion-weighted MRI. In comparison to other USPIOs, ferumoxytol is less limited by allergic and idiosyncratic reactions. Furthermore, since ferumoxytol is an iron-based agent with no potential for causing nephrogenic systemic fibrosis, it may be useful as an alternative to gadolinium-based contrast agents in patients with compromised renal function. Ferumoxytol is ultimately taken up by macrophages/the reticuloendothelial system in the liver, spleen, and lymph nodes, and this uptake mechanism is being explored as a novel imaging technique for vascular lesions, tumors, and lymph nodes. This article reviews the properties of ferumoxytol relevant to MRI as well as many of the uses for the agent currently under investigation.

Authors
Bashir, MR; Bhatti, L; Marin, D; Nelson, RC
MLA Citation
Bashir, MR, Bhatti, L, Marin, D, and Nelson, RC. "Emerging applications for ferumoxytol as a contrast agent in MRI." Journal of Magnetic Resonance Imaging 41.4 (2015): 884-898.
Source
scival
Published In
Journal of Magnetic Resonance Imaging
Volume
41
Issue
4
Publish Date
2015
Start Page
884
End Page
898
DOI
10.1002/jmri.24691

On confirmation bias in imaging research

Authors
Bashir, MR; Sirlin, CB; Reeder, SB
MLA Citation
Bashir, MR, Sirlin, CB, and Reeder, SB. "On confirmation bias in imaging research." Journal of Magnetic Resonance Imaging 41.5 (2015): 1163-1164.
Source
scival
Published In
Journal of Magnetic Resonance Imaging
Volume
41
Issue
5
Publish Date
2015
Start Page
1163
End Page
1164
DOI
10.1002/jmri.24720

Effect of Vitamin D supplementation on glycemic parameters and progression of prediabetes to diabetes: A 1-year, open-label randomized study

Authors
Laway, B; Bashir, M; Wani, A; Misgar, R; Shah, Z; Kuchay, M
MLA Citation
Laway, B, Bashir, M, Wani, A, Misgar, R, Shah, Z, and Kuchay, M. "Effect of Vitamin D supplementation on glycemic parameters and progression of prediabetes to diabetes: A 1-year, open-label randomized study." Indian Journal of Endocrinology and Metabolism 19.3 (2015): 387-387.
Source
crossref
Published In
Indian Journal of Endocrinology and Metabolism
Volume
19
Issue
3
Publish Date
2015
Start Page
387
End Page
387
DOI
10.4103/2230-8210.152783

Is diaphragm motion a good surrogate for liver tumor motion?

To evaluate the relationship between liver tumor motion and diaphragm motion.Fourteen patients with hepatocellular carcinoma (10 of 14) or liver metastases (4 of 14) undergoing radiation therapy were included in this study. All patients underwent single-slice cine-magnetic resonance imaging simulations across the center of the tumor in 3 orthogonal planes. Tumor and diaphragm motion trajectories in the superior-inferior (SI), anterior-posterior (AP), and medial-lateral (ML) directions were obtained using an in-house-developed normalized cross-correlation-based tracking technique. Agreement between the tumor and diaphragm motion was assessed by calculating phase difference percentage, intraclass correlation coefficient, and Bland-Altman analysis (Diff). The distance between the tumor and tracked diaphragm area was analyzed to understand its impact on the correlation between the 2 motions.Of all patients, the mean (±standard deviation) phase difference percentage values were 7.1% ± 1.1%, 4.5% ± 0.5%, and 17.5% ± 4.5% in the SI, AP, and ML directions, respectively. The mean intraclass correlation coefficient values were 0.98 ± 0.02, 0.97 ± 0.02, and 0.08 ± 0.06 in the SI, AP, and ML directions, respectively. The mean Diff values were 2.8 ± 1.4 mm, 2.4 ± 1.1 mm, and 2.2 ± 0.5 mm in the SI, AP, and ML directions, respectively. Tumor and diaphragm motions had high concordance when the distance between the tumor and tracked diaphragm area was small.This study showed that liver tumor motion had good correlation with diaphragm motion in the SI and AP directions, indicating diaphragm motion in the SI and AP directions could potentially be used as a reliable surrogate for liver tumor motion.

Authors
Yang, J; Cai, J; Wang, H; Chang, Z; Czito, BG; Bashir, MR; Palta, M; Yin, F-F
MLA Citation
Yang, J, Cai, J, Wang, H, Chang, Z, Czito, BG, Bashir, MR, Palta, M, and Yin, F-F. "Is diaphragm motion a good surrogate for liver tumor motion?." International journal of radiation oncology, biology, physics 90.4 (November 2014): 952-958.
PMID
25223297
Source
epmc
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
90
Issue
4
Publish Date
2014
Start Page
952
End Page
958
DOI
10.1016/j.ijrobp.2014.07.028

Liver fat quantification using a multi-step adaptive fitting approach with multi-echo GRE imaging.

The purpose of this study was to develop a multi-step adaptive fitting approach for liver proton density fat fraction (PDFF) and R(2)* quantification, and to perform an initial validation on a broadly available hardware platform.The proposed method uses a multi-echo three-dimensional gradient echo acquisition, with initial guesses for the fat and water signal fractions based on a Dixon decomposition of two selected echoes. Based on magnitude signal equations with a multi-peak fat spectral model, a multi-step nonlinear fitting procedure is then performed to adaptively update the fat and water signal fractions and R(2)* values. The proposed method was validated using numeric phantoms as ground truth, followed by preliminary clinical validation of PDFF calculations against spectroscopy in 30 patients.The results of the proposed method agreed well with the ground truth of numerical phantoms, and were relatively insensitive to changes in field strength, field homogeneity, monopolar/bipolar readout, signal to noise ratio, and echo time selections. The in vivo patient study showed excellent consistency between the PDFF values measured with the proposed approach compared with spectroscopy.This multi-step adaptive fitting approach performed well in both simulated and initial clinical evaluation, and shows potential in the quantification of hepatic steatosis.

Authors
Zhong, X; Nickel, MD; Kannengiesser, SAR; Dale, BM; Kiefer, B; Bashir, MR
MLA Citation
Zhong, X, Nickel, MD, Kannengiesser, SAR, Dale, BM, Kiefer, B, and Bashir, MR. "Liver fat quantification using a multi-step adaptive fitting approach with multi-echo GRE imaging." Magnetic resonance in medicine 72.5 (November 2014): 1353-1365.
PMID
24323332
Source
epmc
Published In
Magnetic Resonance in Medicine
Volume
72
Issue
5
Publish Date
2014
Start Page
1353
End Page
1365
DOI
10.1002/mrm.25054

Image-guided percutaneous drainage vs. surgical repair of gastrointestinal anastomotic leaks: is there a difference in hospital course or hospitalization cost?

© 2014, Springer Science+Business Media New York.Purpose: To identify differences in hospital course and hospitalization cost when comparing image-guided percutaneous drainage with surgical repair for gastrointestinal anastomotic leaks. Materials and methods: A retrospective IRB-approved search using key words “leak” and/or “anastomotic” was performed on all adult CT reports from 2002 to 2011. CT examinations were reviewed for evidence of a postoperative gastrointestinal leak and assigned a confidence score of 1–5 (1 = no leak, 5 = definite leak). Patients with an average confidence score <4 were excluded. Type of surgery, patient data, method of leak management, number of hospital admissions, length of hospital stay, discharge disposition, number of CT examinations, number of drains, and hospitalization costs were collected. Results: One hundred thirty-nine patients had radiographic evidence of a gastrointestinal anastomotic leak (esophageal, gastric, small bowel or colonic). Nine patients were excluded due to low confidence scores. Twenty-seven patients underwent surgical repair (Group A) and 103 were managed entirely with percutaneous image-guided drainage (Group B). There was no significant difference in patient demographics or number of hospital admissions. Patients in Group A had longer median hospital stays compared to Group B (48 vs. 32 days, p = 0.007). The median total hospitalization cost for Group A was more than twice that for Group B ($99,995 vs. $47,838, p = 0.001). Differences in hospital disposition, number of CT examinations, number of drains, and time between original surgery and first CT examination were statistically significant. Conclusion: Gastrointestinal anastomotic leaks managed by percutaneous drainage are associated with lower hospital cost and shorter hospital stays compared with surgical management.

Authors
Burke, LMB; Bashir, MR; Gardner, CS; Parsee, AA; Marin, D; Vermess, D; Bhattacharya, SD; Thacker, JK; Jaffe, TA
MLA Citation
Burke, LMB, Bashir, MR, Gardner, CS, Parsee, AA, Marin, D, Vermess, D, Bhattacharya, SD, Thacker, JK, and Jaffe, TA. "Image-guided percutaneous drainage vs. surgical repair of gastrointestinal anastomotic leaks: is there a difference in hospital course or hospitalization cost?." Abdominal Imaging 40.5 (October 8, 2014): 1279-1284.
Source
scopus
Published In
Abdominal Imaging
Volume
40
Issue
5
Publish Date
2014
Start Page
1279
End Page
1284
DOI
10.1007/s00261-014-0265-z

CME update: review articles and commentaries in JMRI.

Authors
Bashir, MR; Korosec, FR; Reeder, SB
MLA Citation
Bashir, MR, Korosec, FR, and Reeder, SB. "CME update: review articles and commentaries in JMRI." Journal of magnetic resonance imaging : JMRI 40.4 (October 2014): 778-.
PMID
24912926
Source
epmc
Published In
Journal of Magnetic Resonance Imaging
Volume
40
Issue
4
Publish Date
2014
Start Page
778
DOI
10.1002/jmri.24670

Investigation of sagittal image acquisition for 4D-MRI with body area as respiratory surrogate.

The authors have recently developed a novel 4D-MRI technique for imaging organ respiratory motion employing cine acquisition in the axial plane and using body area (BA) as a respiratory surrogate. A potential disadvantage associated with axial image acquisition is the space-dependent phase shift in the superior-inferior (SI) direction, i.e., different axial slice positions reach the respiratory peak at different respiratory phases. Since respiratory motion occurs mostly in the SI and anterior-posterior (AP) directions, sagittal image acquisition, which embeds motion information in these two directions, is expected to be more robust and less affected by phase-shift than axial image acquisition. This study aims to develop and evaluate a 4D-MRI technique using sagittal image acquisition.The authors evaluated axial BA and sagittal BA using both 4D-CT images (11 cancer patients) and cine MR images (6 healthy volunteers and 1 cancer patient) by comparing their corresponding space-dependent phase-shift in the SI direction (δSPS (SI)) and in the lateral direction (δSPS (LAT)), respectively. To evaluate sagittal BA 4D-MRI method, a motion phantom study and a digital phantom study were performed. Additionally, six patients who had cancer(s) in the liver were prospectively enrolled in this study. For each patient, multislice sagittal MR images were acquired for 4D-MRI reconstruction. 4D retrospective sorting was performed based on respiratory phases. Single-slice cine MRI was also acquired in the axial, coronal, and sagittal planes across the tumor center from which tumor motion trajectories in the SI, AP, and medial-lateral (ML) directions were extracted and used as references from comparison. All MR images were acquired in a 1.5 T scanner using a steady-state precession sequence (frame rate ∼ 3 frames/s).4D-CT scans showed that δSPS (SI) was significantly greater than δSPS (LAT) (p-value: 0.012); the median phase-shift was 16.9% and 7.7%, respectively. Body surface motion measurement from axial and sagittal MR cines also showed δSPS (SI) was significantly greater than δSPS (LAT). The median δSPS (SI) and δSPS (LAT) was 11.0% and 9.2% (p-value = 0.008), respectively. Tumor motion trajectories from 4D-MRI matched with those from single-slice cine MRI: the mean (±SD) absolute differences in tumor motion amplitude between the two were 1.5 ± 1.6 mm, 2.1 ± 1.9 mm, and 1.1 ± 1.0 mm in the SI, ML, and AP directions from this patient study.Space-dependent phase shift is less problematic for sagittal acquisition than for axial acquisition. 4D-MRI using sagittal acquisition was successfully carried out in patients with hepatic tumors.

Authors
Liu, Y; Yin, F-F; Chang, Z; Czito, BG; Palta, M; Bashir, MR; Qin, Y; Cai, J
MLA Citation
Liu, Y, Yin, F-F, Chang, Z, Czito, BG, Palta, M, Bashir, MR, Qin, Y, and Cai, J. "Investigation of sagittal image acquisition for 4D-MRI with body area as respiratory surrogate." Medical physics 41.10 (October 2014): 101902-.
PMID
25281954
Source
epmc
Published In
Medical physics
Volume
41
Issue
10
Publish Date
2014
Start Page
101902
DOI
10.1118/1.4894726

Dose-toxicity relationship of gadoxetate disodium and transient severe respiratory motion artifact.

The purpose of this article is to determine whether there is a dose-toxicity relationship between gadoxetate disodium and transient severe respiratory motion artifact.Gadoxetate disodium-enhanced MRI studies (559 studies of 559 patients) using a fixed 20-mL (2 mL/s; n = 112) or 10-mL (1-2 mL/s; n = 447) volume at two health systems were included (dose range, 0.05-0.42 mL/kg; mean, 0.15 mL/kg; above-label dosing, 479 [86%]). Each dynamic phase was assigned a respiratory motion score from 1 (none) to 5 (nondiagnostic). Examinations with an unenhanced score of 1-2, arterial score of 4-5, and venous or late-dynamic scores of 1-3 were labeled as transient severe respiratory motion artifact. Stepwise multivariate logistic regression was performed.The overall incidence of transient severe respiratory motion artifact was 12% (67/559; site 1, 15% [35/232]; site 2, 9.8% [32/327]). The administered volume of contrast material had a statistically significant effect (20 mL, 20% [22/112] vs 10 mL, 10%, [45/447]; multivariate p = 0.01; odds ratio, 2.1 [20 vs 10 mL]; 95% CI, 1.2-3.7). There was no dose-toxicity relationship for dose-by-weight (p = 0.61 [multivariate]) or above-label dosing (p = 0.88 [univariate]; 13% [10/80] rate for at- or below-label dosing vs 12% [57/479] rate for above-label dosing). Chronic obstructive pulmonary disease was the only non-dose-related predictor in the multivariate model (p < 0.0001; OR, 5.1 [95% CI, 2.5-11.5]; 39% [12/31] vs 10% [55/528]).Gadoxetate disodium-associated transient severe respiratory motion artifact is significantly more common after 20-mL administration (2 mL/s) and occurs significantly more often in patients with chronic obstructive pulmonary disease. The volume-related effect suggests a nonallergiclike mechanism.

Authors
Davenport, MS; Bashir, MR; Pietryga, JA; Weber, JT; Khalatbari, S; Hussain, HK
MLA Citation
Davenport, MS, Bashir, MR, Pietryga, JA, Weber, JT, Khalatbari, S, and Hussain, HK. "Dose-toxicity relationship of gadoxetate disodium and transient severe respiratory motion artifact." AJR. American journal of roentgenology 203.4 (October 2014): 796-802.
PMID
25055154
Source
epmc
Published In
AJR. American journal of roentgenology
Volume
203
Issue
4
Publish Date
2014
Start Page
796
End Page
802
DOI
10.2214/ajr.13.11587

Magnetic resonance contrast agents for liver imaging.

Intravenous contrast agents are important in the performance of liver magnetic resonance (MR) imaging. These agents differ in their physical properties. These differences can be exploited to optimize imaging protocols based on indications for examination. Institutional protocols should be designed to take advantage of the variety of available contrast agent types. Important contrast agent properties including relaxivity and biodistribution are discussed in this article. Practitioners administering contrast agents for MR imaging should be familiar with potential safety issues and establish rational safety guidelines based on available data. Precautions in at-risk populations are discussed, and sample institutional guidelines are provided.

Authors
Bashir, MR
MLA Citation
Bashir, MR. "Magnetic resonance contrast agents for liver imaging." Magnetic resonance imaging clinics of North America 22.3 (August 2014): 283-293.
PMID
25086930
Source
epmc
Published In
Magnetic Resonance Imaging Clinics of North America
Volume
22
Issue
3
Publish Date
2014
Start Page
283
End Page
293
DOI
10.1016/j.mric.2014.04.002

Iron deficiency in patients with nonalcoholic Fatty liver disease is associated with obesity, female gender, and low serum hepcidin.

Iron deficiency is often observed in obese individuals. The iron regulatory hormone hepcidin is regulated by iron and cytokines interleukin (IL) 6 and IL1β. We examine the relationship between obesity, circulating levels of hepcidin, and IL6 and IL1β, and other risk factors in patients with nonalcoholic fatty liver disease (NAFLD) with iron deficiency.We collected data on 675 adult subjects (>18 years old) enrolled in the Nonalcoholic Steatohepatitis Clinical Research Network. Subjects with transferrin saturation <20% were categorized as iron deficient, whereas those with transferrin saturation ≥20% were classified as iron normal. We assessed clinical, demographic, anthropometric, laboratory, dietary, and histologic data from patients, and serum levels of hepcidin and cytokines IL6 and IL1β. Univariate and multivariate analysis were used to identify risk factors for iron deficiency.One-third of patients (231 of 675; 34%) were iron deficient. Obesity, diabetes, and metabolic syndrome were more common in subjects with iron deficiency (P < .01), compared with those that were iron normal. Serum levels of hepcidin were significantly lower in subjects with iron deficiency (61 ± 45 vs 81 ± 51 ng/mL; P < .0001). Iron deficiency was significantly associated with female gender, obesity, increased body mass index and waist circumference, presence of diabetes, lower alcohol consumption, black or American Indian/Alaska Native race (P ≤ .018), and increased levels of IL6 and IL1β (6.6 vs 4.8 for iron normal, P ≤ .0001; and 0.45 vs 0.32 for iron normal, P ≤ .005).Iron deficiency is prevalent in patients with NAFLD and associated with female gender, increased body mass index, and nonwhite race. Serum levels of hepcidin were lower in iron-deficient subjects, reflecting an appropriate physiologic response to decreased circulating levels of iron, rather than a primary cause of iron deficiency in the setting of obesity and NAFLD.

Authors
Siddique, A; Nelson, JE; Aouizerat, B; Yeh, MM; Kowdley, KV
MLA Citation
Siddique, A, Nelson, JE, Aouizerat, B, Yeh, MM, and Kowdley, KV. "Iron deficiency in patients with nonalcoholic Fatty liver disease is associated with obesity, female gender, and low serum hepcidin." Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association 12.7 (July 2014): 1170-1178.
PMID
24269922
Source
epmc
Published In
Clinical Gastroenterology and Hepatology
Volume
12
Issue
7
Publish Date
2014
Start Page
1170
End Page
1178
DOI
10.1016/j.cgh.2013.11.017

Retrospective assessment of the utility of an iron-based agent for contrast-enhanced magnetic resonance venography in patients with endstage renal diseases.

PURPOSE: To compare abdominopelvic and lower extremity venous enhancement in contrast-enhanced magnetic resonance venography (ceMRV), using iron-based ferumoxytol and gadolinium-based gadofosveset. MATERIALS AND METHODS: This was a Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study. Thirty-four patients were identified who had undergone ceMRV using either ferumoxtyol (Group A, all with chronic renal insufficiency) or gadofosveset (Group B). Two radiologists rated confidence for evaluation of the major abdominopelvic and lower extremity veins from 4 (excellent confidence) to 1 (nondiagnostic). A third radiologist measured signal intensity ratios (SIRs) of venous segments compared with adjacent muscles. Scores were compared using repeated-measures analysis of variance (ANOVA). The medical record was searched for contemporaneous imaging to confirm the ceMRV findings. RESULTS: In Group A, 14/225 venous segments were thrombosed, compared with 18/282 in Group B. There was no statistically significant difference between confidence scores (3.79 ± 0.44 vs. 3.85 ± 0.44, P = 0.34) or SIRs (2.40 ± 0.73 vs. 2.38 ± 0.51, P = 0.51) for patent segments in the two groups, nor were confidences scores (3.89 ± 0.29 vs. 3.72 ± 0.46, P = 0.31) or SIRs (0.90 ± 0.12 vs. 0.84 ± 0.19, P = 0.31) significantly different for thrombosed segments. Contemporaneous imaging confirmed ceMRV findings in 227 segments. CONCLUSION: ceMRV can be performed with ferumoxytol, yielding similar image quality to a blood pool gadolinium-based contrast agent.

Authors
Bashir, MR; Mody, R; Neville, A; Javan, R; Seaman, D; Kim, CY; Gupta, RT; Jaffe, TA
MLA Citation
Bashir, MR, Mody, R, Neville, A, Javan, R, Seaman, D, Kim, CY, Gupta, RT, and Jaffe, TA. "Retrospective assessment of the utility of an iron-based agent for contrast-enhanced magnetic resonance venography in patients with endstage renal diseases." J Magn Reson Imaging 40.1 (July 2014): 113-118.
PMID
24130008
Source
pubmed
Published In
Journal of Magnetic Resonance Imaging
Volume
40
Issue
1
Publish Date
2014
Start Page
113
End Page
118
DOI
10.1002/jmri.24330

High variability in radiologists' reporting practices for incidental thyroid nodules detected on CT and MRI.

BACKGROUND AND PURPOSE: There are no guidelines for reporting incidental thyroid nodules seen on CT and MR imaging. We evaluated radiologists' current reporting practices for incidental thyroid nodules detected on these imaging modalities. MATERIALS AND METHODS: Radiologists were surveyed regarding their reporting practices by using 14 scenarios of incidental thyroid nodules differing in size, patient demographics, and clinical history. Scenarios were evaluated for the following: 1) radiologists' most commonly selected response, and 2) the proportion of radiologists selecting that response (degree of agreement). These measures were used to determine how the patient scenario and characteristics of the radiologists affected variability in practice. RESULTS: One hundred fifty-three radiologists participated. In 8/14 scenarios, the most common response was to "recommend sonography." For the other scenarios, the most common response was to "report in only body of report." The overall mean agreement for the 14 scenarios was 53%, and agreement ranged from 36% to 75%. Smaller nodules had lower agreement: 43%-51% for 8-mm nodules compared with 64%-75% for 15-mm nodules. Agreement was poorest for the 10-mm nodule in a 60-year-old woman (36%) and for scenarios with additional history of lung cancer (39%) and multiple nodules (36%). There was no significant difference in reporting practices and agreement when radiologists were categorized by years of practice, practice type, and subspecialty (P > .55). CONCLUSIONS: The reporting practice for incidental thyroid nodules on CT or MR imaging is highly variable among radiologists, especially for patients with smaller nodules (≤10 mm) and patients with multiple nodules and a history of cancer. This variability highlights the need for practice guidelines.

Authors
Hoang, JK; Riofrio, A; Bashir, MR; Kranz, PG; Eastwood, JD
MLA Citation
Hoang, JK, Riofrio, A, Bashir, MR, Kranz, PG, and Eastwood, JD. "High variability in radiologists' reporting practices for incidental thyroid nodules detected on CT and MRI." AJNR Am J Neuroradiol 35.6 (June 2014): 1190-1194.
PMID
24407274
Source
pubmed
Published In
American Journal of Neuroradiology
Volume
35
Issue
6
Publish Date
2014
Start Page
1190
End Page
1194
DOI
10.3174/ajnr.A3834

Vascular artifact mimicking thrombosis on MR imaging using ferumoxytol as a contrast agent in abdominal vascular assessment.

PURPOSE: To describe an artifact that mimics thrombosis when assessing abdominal vasculature on magnetic resonance (MR) imaging using ferumoxytol in patients with contraindications to gadolinium-based contrast agents and to evaluate factors that may contribute to this artifact. MATERIALS AND METHODS: Three radiologists in consensus retrospectively evaluated 61 abdominal MR imaging examinations using ferumoxytol as an intravenous contrast agent for the presence of an observed artifact that can mimic thrombosis. Patient demographics and contrast agent bolus concentrations were compared with an unpaired Wilcoxon signed rank test. RESULTS: An artifact mimicking thrombosis was observed in 30 of 61 examinations, all on the arterial phase sequences. In examinations with this artifact, the average concentration of administered ferumoxytol was greater than in examinations where the artifact was not observed (P < .01). Several additional vascular findings were observed, including portal vein thrombosis (n = 2) and aneurysm (n = 1), renal vein thrombosis (n = 2), abdominal aortic aneurysm (n = 1), abdominal and iliac artery dissection (n = 3), and sequelae of portal hypertension (n = 8). CONCLUSIONS: Although MR imaging using ferumoxytol as an intravenous contrast agent can be useful in detecting abdominal vascular abnormalities, an artifact mimicking vascular thrombosis was observed in nearly half of the examinations.

Authors
Fananapazir, G; Marin, D; Suhocki, PV; Kim, CY; Bashir, MR
MLA Citation
Fananapazir, G, Marin, D, Suhocki, PV, Kim, CY, and Bashir, MR. "Vascular artifact mimicking thrombosis on MR imaging using ferumoxytol as a contrast agent in abdominal vascular assessment." Journal of vascular and interventional radiology : JVIR 25.6 (June 2014): 969-976.
PMID
24630749
Source
epmc
Published In
JVIR: Journal of Vascular and Interventional Radiology
Volume
25
Issue
6
Publish Date
2014
Start Page
969
End Page
976
DOI
10.1016/j.jvir.2013.12.019

Optimal timing and diagnostic adequacy of hepatocyte phase imaging with gadoxetate-enhanced liver MRI.

RATIONALE AND OBJECTIVES: To evaluate clinical and imaging features associated with adequacy of the hepatocyte phase (HP) in gadoxetate disodium-enhanced liver magnetic resonance imaging (MRI) in patients without chronic liver disease (CLD). MATERIALS AND METHODS: This was a retrospective institutional review board-approved study of 97 patients who underwent liver MRI examinations with gadoxetate disodium and had no history of CLD. Available late dynamic and HP sequences (3-20 minutes postinjection) were independently analyzed by four radiologists for perceived image adequacy and level of biliary enhancement. Signal intensity ratios (SIRs) of liver/inferior vena cava (IVC), liver/spleen, and liver/muscle were measured. The Spearman ρ and receiver operating characteristic analyses were performed correlating various factors with HP adequacy. A rule for predicting HP adequacy was also derived and tested to determine whether overall examination time could be shortened. RESULTS: A visually adequate HP was observed in 12% of subjects by 10 minutes, 80% by 15 minutes, and 93% by 20 minutes. An SIRliver/IVC > 1.8 was the imaging feature that had the strongest correlation with an adequate HP (ρ = 0.813, P < .001), and was more predictive of adequacy of the HP than the time postinjection (ρ = 0.5, P < .001). The time at which an adequate HP was first observed did not correlate with any tested demographic or laboratory values. Stopping imaging when an SIRliver/IVC > 1.8 would have successfully reduced mean postcontrast time to 15:39 ± 4:02 from 20:00 (P < .001), although maintaining HP adequacy. CONCLUSIONS: Most patients without CLD undergoing gadoxetate-enhanced liver MRI achieve adequate HP at 20 minutes. However, a shorter postcontrast stopping time can be used in most patients.

Authors
Bashir, MR; Breault, SR; Braun, R; Do, RK; Nelson, RC; Reeder, SB
MLA Citation
Bashir, MR, Breault, SR, Braun, R, Do, RK, Nelson, RC, and Reeder, SB. "Optimal timing and diagnostic adequacy of hepatocyte phase imaging with gadoxetate-enhanced liver MRI." Academic radiology 21.6 (June 2014): 726-732.
PMID
24717550
Source
epmc
Published In
Academic Radiology
Volume
21
Issue
6
Publish Date
2014
Start Page
726
End Page
732
DOI
10.1016/j.acra.2014.02.005

Safety of an intercostal approach for imaging-guided percutaneous drainage of subdiaphragmatic abscesses.

OBJECTIVE: The objective of our study was to test the hypothesis that an intercostal approach to imaging-guided percutaneous subdiaphragmatic abscess drainage is as safe as a subcostal approach. MATERIALS AND METHODS: A cohort of 258 consecutive patients with one or more subdiaphragmatic abscesses referred for imaging-guided (CT or ultrasound) percutaneous drainage was identified. Demographic characteristics and clinical outcomes were compared between patients who underwent drainage catheter placement via an intercostal approach versus those who underwent drainage catheter placement via a subcostal approach. RESULTS: Percutaneous drainage was performed for 441 abscesses in 258 patients in 409 separate procedures (214 via an intercostal approach, 186 by a subcostal approach, and nine by a combined approach). The total number of pleural complications was significantly higher in the intercostal group (56/214 [26.2%]) than the subcostal group (15/186 [8.1%]; p < 0.001). These complications included a significantly higher pneumothorax rate in the intercostal group than the subcostal group (15/214 [7.0%] vs 0/186 [0%], respectively; p < 0.01) and a higher incidence of new or increased pleural effusions (38/214 [17.8%] vs 14/186 [7.5%]; p < 0.01). The incidence of empyema was low and similar between the two groups (intercostal vs subcostal, 3/214 [1.4%] vs 1/186 [0.5%]; p = 0.63). A few of the complications in the patients who underwent an intercostal-approach drainage were clinically significant. Four of the 15 pneumothoraces required thoracostomy tubes and eight of 38 (21.1%) pleural effusions required thoracentesis, none of which was considered infected. CONCLUSION: An intercostal approach for imaging-guided percutaneous drainage is associated with a higher risk of pleural complications; however, most of these complications are minor and should not preclude use of the intercostal approach.

Authors
Preece, SR; Nelson, RC; Bashir, MR; Jaffe, TA; Kim, CY; Haystead, CM
MLA Citation
Preece, SR, Nelson, RC, Bashir, MR, Jaffe, TA, Kim, CY, and Haystead, CM. "Safety of an intercostal approach for imaging-guided percutaneous drainage of subdiaphragmatic abscesses." AJR. American journal of roentgenology 202.6 (June 2014): 1349-1354.
PMID
24848834
Source
epmc
Published In
AJR. American journal of roentgenology
Volume
202
Issue
6
Publish Date
2014
Start Page
1349
End Page
1354
DOI
10.2214/ajr.13.10712

MO-G-18C-04: Improved Synthetic 4D-MRI Using Linear Polynomial Fitting Model.

To reduce deformable image registration error by fitting the displacement vector field (DVF) to smooth the motion trajectory of each pixel in synthetic 4D-MRI.Five patients with cancers in the liver were enrolled in this study. For a 4D MR image data set, the DVF matrices relative to a specific reference phase were calculated using an in-house deformable image registration based on b-spline. The displacement trajectory of each voxel throughout the respiratory cycle was constituted by concatenating the corresponding displacement values from all DVF matrices. A linear polynomial fitting model was then used to fit the DVFs in three spatial and the temporal dimension, respectively. By warpping the source MR images using the remodeled DVFs, we synthesized MR images at selected phases. Tumor motion trajectories were derived from source 4DMRI, original synthetic images and improved synthetic images. These were analyzed in the superior-inferior (SI), anterior-posterior (AP), and mediallateral (ML) directions, respectively. Correlation coefficients (CC) and differences in motion amplitude (D) were calculated for comparison.For all patients, tumor motion trajectories were strongly correlated between source 4D-MRI images and improved synthetic 4D-MRI (mean CC 0.98±0.01). Differences in motion amplitude were small (mean D 0.46±0.14 mm) in all directions. Correlation between source 4D-MRI and original synthetic 4D-MRI was slightly less strong (mean CC 0.97±0.01) and motion amplitude differences were slightly larger (0.55±0.19 mm).The feasibility of synthesizing T2w 4D-MRI using remodeled DVFs has been investigated in this study. Preliminary results in oncologic patients demonstrated the potential of reducing inaccuracies in original synthetic 4DMRI caused by registration errors using the linear polynomial fitting model without much loss of respiratory motion information. NIH (1R21CA165384-01A1), Golfers Against Cancer (GAC) Foundation, The China Scholarship Council (CSC).

Authors
Yang, J; Yin, F; Wang, H; Chang, Z; Czito, B; Bashir, M; Palta, M; Cai, J
MLA Citation
Yang, J, Yin, F, Wang, H, Chang, Z, Czito, B, Bashir, M, Palta, M, and Cai, J. "MO-G-18C-04: Improved Synthetic 4D-MRI Using Linear Polynomial Fitting Model." Medical physics 41.6 (June 2014): 440-.
PMID
28037732
Source
epmc
Published In
Medical physics
Volume
41
Issue
6
Publish Date
2014
Start Page
440
DOI
10.1118/1.4889215

MO-C-17A-02: A Novel Method for Evaluating Hepatic Stiffness Based On 4D-MRI and Deformable Image Registration.

Quantitative imaging of hepatic stiffness has significant potential in radiation therapy, ranging from treatment planning to response assessment. This study aims to develop a novel, noninvasive method to quantify liver stiffness with 3D strains liver maps using 4D-MRI and deformable image registration (DIR).Five patients with liver cancer were imaged with an institutionally developed 4D-MRI technique under an IRB-approved protocol. Displacement vector fields (DVFs) across the liver were generated via DIR of different phases of 4D-MRI. Strain tensor at each voxel of interest (VOI) was computed from the relative displacements between the VOI and each of the six adjacent voxels. Three principal strains (E1 , E2 and E3 ) of the VOI were derived as the eigenvalue of the strain tensor, which represent the magnitudes of the maximum and minimum stretches. Strain tensors for two regions of interest (ROIs) were calculated and compared for each patient, one within the tumor (ROI1 ) and the other in normal liver distant from the heart (ROI2 ).3D strain maps were successfully generated fort each respiratory phase of 4D-MRI for all patients. Liver deformations induced by both respiration and cardiac motion were observed. Differences in strain values adjacent to the distant from the heart indicate significant deformation caused by cardiac expansion during diastole. The large E1 /E2 (∼2) and E1 /E2 (∼10) ratios reflect the predominance of liver deformation in the superior-inferior direction. The mean E1 in ROI1 (0.12±0.10) was smaller than in ROI2 (0.15±0.12), reflecting a higher degree of stiffness of the cirrhotic tumor.We have successfully developed a novel method for quantitatively evaluating regional hepatic stiffness based on DIR of 4D-MRI. Our initial findings indicate that liver strain is heterogeneous, and liver tumors may have lower principal strain values than normal liver. Thorough validation of our method is warranted in future studies. NIH (1R21CA165384-01A1).

Authors
Cui, T; Liang, X; Czito, B; Palta, M; Bashir, M; Yin, F; Cai, J
MLA Citation
Cui, T, Liang, X, Czito, B, Palta, M, Bashir, M, Yin, F, and Cai, J. "MO-C-17A-02: A Novel Method for Evaluating Hepatic Stiffness Based On 4D-MRI and Deformable Image Registration." Medical physics 41.6 (June 2014): 414-.
PMID
28036864
Source
epmc
Published In
Medical physics
Volume
41
Issue
6
Publish Date
2014
Start Page
414
DOI
10.1118/1.4889125

SU-E-J-68: Evaluation of Liver Deformation During Breathing Using Deformable Image Registration: A Comparison Between 4D CT and 4D MRI.

It is of clinical interest to study liver deformation during breathing by applying deformable image registration (DIR) on respiratory correlated 4D images. This study aims to evaluate and compare the accuracy of DIR-derived liver deformation based on 4D CT and 4D MRI.4D CT, 4D MR and cine MR images of liver region were acquired from 5 patients with liver cancer under an IRB-approved protocol. Tumor trajectories were tracked from cine MR images. DVFs from 4D CT and 4D MR were generated via DIR implemented in Velocity AI. To enable comparison between DVFs and tumor trajectories from cine images, deformation vectors from each frame were linked together, forming DVF-based trajectories. All DVF-based trajectories within each tumor region were averaged. Absolute difference, relative difference and correlation coefficient between each pair of averaged DVF-based trajectory and trajectory from cine MR images were calculated.All metrics did not give consistent indications of which modality can provide more accurate DVFs. In superior-inferior (SI) direction, averaging over all the five patients, 4D CT trajectories exhibited smaller absolute (2.05±0.52mm) and relative difference (0.43±0.14) and larger correlation coefficient (0.92±0.06) than 4D MR trajectories (2.54±1.45mm, 0.47±0.18, 0.88±0.10) whereas 4D MR (1.02±1.20mm, 0.90±0.69, 0.59±0.30) surpassed 4D CT (1.35±1.42mm, 1.35±1.25, 0.12±0.64) in every metric in right-left direction. In anterior-posterior direction, 4D MR trajectories has smaller absolute (1.17±0.74mm) and relative difference (0.50±0.18) with slightly smaller correlation coefficient (0.72±0.23) than 4D CT trajectories (1.51±0.64mm, 0.69±0.09, 0.75±0.26).We have implemented a novel approach for evaluating accuracy of DVFs based on 4D imaging for studying liver deformation. Initial results indicate that DVFs from 4D CT and 4D MRI are comparable. Further study on more patients is warranted and is undergoing to determine whether there is significant difference between 4D CT and 4D MRI.

Authors
Liang, X; Czito, B; Palta, M; Bashir, M; Yin, F; Cai, J
MLA Citation
Liang, X, Czito, B, Palta, M, Bashir, M, Yin, F, and Cai, J. "SU-E-J-68: Evaluation of Liver Deformation During Breathing Using Deformable Image Registration: A Comparison Between 4D CT and 4D MRI." Medical physics 41.6 (June 2014): 171-.
PMID
28037625
Source
epmc
Published In
Medical physics
Volume
41
Issue
6
Publish Date
2014
Start Page
171
DOI
10.1118/1.4888120

WE-G-18C-06: Is Diaphragm Motion a Good Surrogate for Liver Tumor Motion?

To investigate whether diaphragm motion is a good surrogate for liver tumor motion by comparing their motion trajectories obtained from cine-MRI.Fourteen patients with hepatocellular carcinoma (10/14) or liver metastases (4/14) undergoing radiation therapy were included in this study. All patients underwent single-slice 2D cine-MRI simulations across the center of the tumor in three orthogonal planes. Tumor and diaphragm motion trajectories in the superior-inferior (SI), anteriorposterior (AP), and medial-lateral (ML) directions were obtained using the normalized cross-correlation based tracking technique. Agreement between tumor and diaphragm motions was assessed by calculating the phase difference percentage (PDP), intra-class correlation coefficient (ICC), Bland-Altman analysis (Diffs) and paired t-test. The distance (D) between tumor and tracked diaphragm area was analyzed to understand its impact on the correlation between tumor and diaphragm motions.Of all patients, the means (±standard deviations) of PDP were 7.1 (±1.1)%, 4.5 (±0.5)% and 17.5 (±4.5)% in the SI, AP and ML directions, respectively. The means of ICC were 0.98 (±0.02), 0.97 (±0.02), and 0.08 (±0.06) in the SI, AP and ML directions, respectively. The Diffs were 2.8 (±1.4) mm, 2.4 (±1.1) mm, and 2.2 (±0.5) mm in the SI, AP and ML directions, respectively. The p-values derived from the paired t-test were < 0.02 in SI and AP directions, whereas were > 0.58 in ML direction primarily due to the small motion in ML direction. Tumor and diaphragmatic motion had high concordance when the distance between the tumor and tracked diaphragm areas was small.Preliminary results showed that liver tumor motion had good correlations with diaphragm motion in the SI and AP directions, indicating diaphragm motion in the SI and AP directions could potentially be a reliable surrogate for liver tumor motion. NIH (1R21CA165384-01A1), Golfers Against Cancer (GAC) Foundation, The China Scholarship Council (CSC).

Authors
Yang, J; Cai, J; Wang, H; Zheng, C; Czito, B; Bashir, M; Palta, M; Yin, F
MLA Citation
Yang, J, Cai, J, Wang, H, Zheng, C, Czito, B, Bashir, M, Palta, M, and Yin, F. "WE-G-18C-06: Is Diaphragm Motion a Good Surrogate for Liver Tumor Motion?." Medical physics 41.6 (June 2014): 529-.
PMID
28036599
Source
epmc
Published In
Medical physics
Volume
41
Issue
6
Publish Date
2014
Start Page
529
DOI
10.1118/1.4889525

Current opinions on medical radiation: a survey of oncologists regarding radiation exposure and dose reduction in oncology patients.

PURPOSE: The aim of this study was to evaluate oncologists' opinions about the use of ionizing radiation in medical imaging of oncology patients. METHODS: An electronic survey was e-mailed to 2,725 oncologists at the top 50 National Cancer Institute-funded cancer centers. The survey focused on opinions on CT dose reduction in oncology patients and current philosophies behind long-term imaging in these patients. RESULTS: The response rate was 15% (415 of 2,725). Eighty-two percent of respondents stated that their patients or families have expressed anxiety regarding radiation dose from medical imaging. Although fewer than half of oncologists (48%) did not know whether CT dose reduction techniques were used at their institutions, only 25% were concerned that small lesions may be missed with low-dose CT techniques. The majority of oncologists (63%) follow National Comprehensive Cancer Network guidelines for imaging follow-up, while the remainder follow other national guidelines such as those of the Children's Oncology Group, the American Society of Clinical Oncology, or clinical trials. Ninety percent of respondents believe that long-term surveillance in oncology patients is warranted, particularly in patients with breast cancer, melanoma, sarcoma, and pediatric malignancies. The majority of oncologists would consider the use of low-dose CT imaging in specific patient populations: (1) children and young women, (2) those with malignancies that do not routinely metastasize to the liver, and (3) patients undergoing surveillance imaging. CONCLUSIONS: Cumulative radiation exposure is a concern for patients and oncologists. Among oncologists, there is support for long-term imaging surveillance despite lack of national guidelines.

Authors
Burke, LMB; Bashir, MR; Neville, AM; Nelson, RC; Jaffe, TA
MLA Citation
Burke, LMB, Bashir, MR, Neville, AM, Nelson, RC, and Jaffe, TA. "Current opinions on medical radiation: a survey of oncologists regarding radiation exposure and dose reduction in oncology patients." J Am Coll Radiol 11.5 (May 2014): 490-495.
PMID
24321221
Source
pubmed
Published In
Journal of the American College of Radiology
Volume
11
Issue
5
Publish Date
2014
Start Page
490
End Page
495
DOI
10.1016/j.jacr.2013.08.018

Respiratory motion artifact affecting hepatic arterial phase imaging with gadoxetate disodium: examination recovery with a multiple arterial phase acquisition.

PURPOSE: To determine whether the use of a multiple arterial phase imaging technique provides adequate image quality in patients experiencing transient severe motion (TSM) in the arterial phase on abdominal magnetic resonance (MR) images obtained with gadoxetate disodium. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board and was compliant with HIPAA. The requirement to obtain informed consent was waived. Five hundred forty-nine consecutive MR examinations were evaluated, 345 performed with gadoxetate disodium and 204 performed with gadobenate dimeglumine. All examinations included single-breath-hold triple arterial phase acquisition. Five radiologists blinded to the contrast material rated motion on a scale of 1 (no motion) to 5 (nondiagnostic images) for the precontrast phase, the three arterial phases, the portal venous phase, and the late dynamic phase. Adequacy of late hepatic arterial timing was also rated for the each of the three arterial phases. Mean motion scores were compared by using the Wilcoxon signed rank test. The number of patients with TSM, as well as the number of those with "adequate" arterial phases, was compared with the χ(2) or Fisher exact test, as appropriate. RESULTS: Mean motion scores in all three arterial phases in the gadoxetate disodium cohort were significantly worse than those in the gadobenate dimeglumine cohort (P < .005). TSM occurred at a higher rate with gadoxetate disodium than with gadobenate dimeglumine (10.7% [37 of 345 examinations] vs 0.5% [one of 204 examinations], P < .001). However, 30 of 37 examinations affected by TSM had at least one well-timed arterial phase with a mean motion score of 3 or less and were thus considered adequate. CONCLUSION: Use of single-breath-hold multiple arterial phase acquisition in abdominal MR imaging with gadoxetate disodium recovers most arterial phases that would otherwise have been compromised by transient motion.

Authors
Pietryga, JA; Burke, LMB; Marin, D; Jaffe, TA; Bashir, MR
MLA Citation
Pietryga, JA, Burke, LMB, Marin, D, Jaffe, TA, and Bashir, MR. "Respiratory motion artifact affecting hepatic arterial phase imaging with gadoxetate disodium: examination recovery with a multiple arterial phase acquisition." Radiology 271.2 (May 2014): 426-434.
PMID
24475864
Source
epmc
Published In
Radiology
Volume
271
Issue
2
Publish Date
2014
Start Page
426
End Page
434
DOI
10.1148/radiol.13131988

May-Thurner syndrome complicating left-sided donor nephrectomy.

Authors
Rege, AS; Rendell, VR; Shrimal, A; Engstrom, BI; Miller, MJ; Bashir, MR; Brennan, TV
MLA Citation
Rege, AS, Rendell, VR, Shrimal, A, Engstrom, BI, Miller, MJ, Bashir, MR, and Brennan, TV. "May-Thurner syndrome complicating left-sided donor nephrectomy." Transplantation 97.7 (April 2014): e40-e41.
PMID
24686428
Source
epmc
Published In
Transplantation
Volume
97
Issue
7
Publish Date
2014
Start Page
e40
End Page
e41
DOI
10.1097/tp.0000000000000044

Four-dimensional magnetic resonance imaging using axial body area as respiratory surrogate: Initial patient results

Purpose To evaluate the feasibility of a retrospective binning technique for 4-dimensional magnetic resonance imaging (4D-MRI) using body area (BA) as a respiratory surrogate. Methods and Materials Seven patients with hepatocellular carcinoma (4 of 7) or liver metastases (3 of 7) were enrolled in an institutional review board-approved prospective study. All patients were simulated with both computed tomography (CT) and MRI to acquire 3-dimensinal and 4D images for treatment planning. Multiple-slice multiple-phase cine-MR images were acquired in the axial plane for 4D-MRI reconstruction. Image acquisition time per slice was set to 10-15 seconds. Single-slice 2-dimensinal cine-MR images were also acquired across the center of the tumor in orthogonal planes. Tumor motion trajectories from 4D-MRI, cine-MRI, and 4D-CT were analyzed in the superior-inferior (SI), anterior-posterior (AP), and medial-lateral (ML) directions, respectively. Their correlation coefficients (CC) and differences in tumor motion amplitude were determined. Tumor-to-liver contrast-to-noise ratio (CNR) was measured and compared between 4D-CT, 4D-MRI, and conventional T2-weighted fast spin echo MRI. Results The means (±standard deviations) of CC comparing 4D-MRI with cine-MRI were 0.97 ± 0.03, 0.97 ± 0.02, and 0.99 ± 0.04 in SI, AP, and ML directions, respectively. The mean differences were 0.61 ± 0.17 mm, 0.32 ± 0.17 mm, and 0.14 ± 0.06 mm in SI, AP, and ML directions, respectively. The means of CC comparing 4D-MRI and 4D-CT were 0.95 ± 0.02, 0.94 ± 0.02, and 0.96 ± 0.02 in SI, AP, and ML directions, respectively. The mean differences were 0.74 ± 0.02 mm, 0.33 ± 0.13 mm, and 0.18 ± 0.07 mm in SI, AP, and ML directions, respectively. The mean tumor-to-tissue CNRs were 2.94 ± 1.51, 19.44 ± 14.63, and 39.47 ± 20.81 in 4D-CT, 4D-MRI, and T2-weighted MRI, respectively. Conclusions The preliminary evaluation of our 4D-MRI technique results in oncologic patients demonstrates its potential usefulness to accurately measure tumor respiratory motion with improved tumor CNR compared with 4D-CT. © 2014 Elsevier Inc. All rights reserved.

Authors
Yang, J; Cai, J; Wang, H; Chang, Z; Czito, BG; Bashir, MR; Yin, FF
MLA Citation
Yang, J, Cai, J, Wang, H, Chang, Z, Czito, BG, Bashir, MR, and Yin, FF. "Four-dimensional magnetic resonance imaging using axial body area as respiratory surrogate: Initial patient results." International Journal of Radiation Oncology Biology Physics 88.4 (March 15, 2014): 907-912.
Source
scopus
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
88
Issue
4
Publish Date
2014
Start Page
907
End Page
912
DOI
10.1016/j.ijrobp.2013.11.245

Four-dimensional magnetic resonance imaging using axial body area as respiratory surrogate: initial patient results.

To evaluate the feasibility of a retrospective binning technique for 4-dimensional magnetic resonance imaging (4D-MRI) using body area (BA) as a respiratory surrogate.Seven patients with hepatocellular carcinoma (4 of 7) or liver metastases (3 of 7) were enrolled in an institutional review board-approved prospective study. All patients were simulated with both computed tomography (CT) and MRI to acquire 3-dimensional and 4D images for treatment planning. Multiple-slice multiple-phase cine-MR images were acquired in the axial plane for 4D-MRI reconstruction. Image acquisition time per slice was set to 10-15 seconds. Single-slice 2-dimensional cine-MR images were also acquired across the center of the tumor in orthogonal planes. Tumor motion trajectories from 4D-MRI, cine-MRI, and 4D-CT were analyzed in the superior-inferior (SI), anterior-posterior (AP), and medial-lateral (ML) directions, respectively. Their correlation coefficients (CC) and differences in tumor motion amplitude were determined. Tumor-to-liver contrast-to-noise ratio (CNR) was measured and compared between 4D-CT, 4D-MRI, and conventional T2-weighted fast spin echo MRI.The means (± standard deviations) of CC comparing 4D-MRI with cine-MRI were 0.97 ± 0.03, 0.97 ± 0.02, and 0.99 ± 0.04 in SI, AP, and ML directions, respectively. The mean differences were 0.61 ± 0.17 mm, 0.32 ± 0.17 mm, and 0.14 ± 0.06 mm in SI, AP, and ML directions, respectively. The means of CC comparing 4D-MRI and 4D-CT were 0.95 ± 0.02, 0.94 ± 0.02, and 0.96 ± 0.02 in SI, AP, and ML directions, respectively. The mean differences were 0.74 ± 0.02 mm, 0.33 ± 0.13 mm, and 0.18 ± 0.07 mm in SI, AP, and ML directions, respectively. The mean tumor-to-tissue CNRs were 2.94 ± 1.51, 19.44 ± 14.63, and 39.47 ± 20.81 in 4D-CT, 4D-MRI, and T2-weighted MRI, respectively.The preliminary evaluation of our 4D-MRI technique results in oncologic patients demonstrates its potential usefulness to accurately measure tumor respiratory motion with improved tumor CNR compared with 4D-CT.

Authors
Yang, J; Cai, J; Wang, H; Chang, Z; Czito, BG; Bashir, MR; Yin, F-F
MLA Citation
Yang, J, Cai, J, Wang, H, Chang, Z, Czito, BG, Bashir, MR, and Yin, F-F. "Four-dimensional magnetic resonance imaging using axial body area as respiratory surrogate: initial patient results." International journal of radiation oncology, biology, physics 88.4 (March 2014): 907-912.
PMID
24444759
Source
epmc
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
88
Issue
4
Publish Date
2014
Start Page
907
End Page
912
DOI
10.1016/j.ijrobp.2013.11.245

Quantitative whole-body muscle MRI, clinical muscle group weakness, and muscle-map correlation in adult patients with Pompe disease

Authors
Austin, S; Horvath, J; Javin, R; Case, L; Greene, K; Soher, BJ; Kishnani, P; Bashir, M
MLA Citation
Austin, S, Horvath, J, Javin, R, Case, L, Greene, K, Soher, BJ, Kishnani, P, and Bashir, M. "Quantitative whole-body muscle MRI, clinical muscle group weakness, and muscle-map correlation in adult patients with Pompe disease." February 2014.
Source
wos-lite
Published In
Molecular Genetics and Metabolism
Volume
111
Issue
2
Publish Date
2014
Start Page
S21
End Page
S22
DOI
10.1016/j.ymgme.201312.030

Impact of precontrast T10 relaxation times on dynamic contrast-enhanced MRI pharmacokinetic parameters: T10 mapping versus a fixed T10 reference value

Purpose To investigate variation in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) pharmacokinetic parameter measurements between different methods of precontrast tissue relaxation (T10) estimation: pixel-based mapping versus a fixed reference value. Materials and Methods In 15 DCE-MRI studies the female pelvis, uterine fibroids, the left psoas muscle, and the fifth lumbar vertebral body were chosen to represent tissues with varying perfusion characteristics. All DCE-MRI studies were processed using a variable flip angle T10 map and a fixed T10 reference value of 1000 msec. A subset of five DCE-MRI studies were each processed multiple times using the fixed T10 method with the reference T10 ranging from 0-2000 msec in 100-msec increments. Pharmacokinetic measurements of K trans, kep, ve, and initial area under the gadolinium curve (iAUGC) were performed maintaining the identical position for region of interest placement on each structure. Results The mean difference in pharmacokinetic output between the pixel-based T10 map and the fixed T10 reference value ranged from 6.6% for kep in the muscle to 54.9% for iAUGC in the vertebral body. At lower T10 (<1000 msec) aberrations in T10 estimation resulted in a larger error. Accurate measurement of T10 for each structure subsequently incorporated as a fixed T10 reference value yielded relative differences from -41.8% to 22.3% compared to the pixel-based T10 map. Conclusion Direct comparison of pharmacokinetic parameters derived from a pixel-based approach versus a reference value uniformly applied to all pixels for T10 estimation is impeded by the inherent spatial heterogeneity of T10 within tissues. J. Magn. Reson. Imaging 2014;39:1136-1145. © 2013 Wiley Periodicals, Inc. Copyright © 2013 Wiley Periodicals, Inc.

Authors
Heye, T; Boll, DT; Reiner, CS; Bashir, MR; Dale, BM; Merkle, EM
MLA Citation
Heye, T, Boll, DT, Reiner, CS, Bashir, MR, Dale, BM, and Merkle, EM. "Impact of precontrast T10 relaxation times on dynamic contrast-enhanced MRI pharmacokinetic parameters: T10 mapping versus a fixed T10 reference value." Journal of Magnetic Resonance Imaging 39.5 (January 1, 2014): 1136-1145.
Source
scopus
Published In
Journal of Magnetic Resonance Imaging
Volume
39
Issue
5
Publish Date
2014
Start Page
1136
End Page
1145
DOI
10.1002/jmri.24262

Current opinions on medical radiation: A survey of oncologists regarding radiation exposure and dose reduction in oncology patients

Purpose The aim of this study was to evaluate oncologists' opinions about the use of ionizing radiation in medical imaging of oncology patients. Methods An electronic survey was e-mailed to 2,725 oncologists at the top 50 National Cancer Institute-funded cancer centers. The survey focused on opinions on CT dose reduction in oncology patients and current philosophies behind long-term imaging in these patients. Results The response rate was 15% (415 of 2,725). Eighty-two percent of respondents stated that their patients or families have expressed anxiety regarding radiation dose from medical imaging. Although fewer than half of oncologists (48%) did not know whether CT dose reduction techniques were used at their institutions, only 25% were concerned that small lesions may be missed with low-dose CT techniques. The majority of oncologists (63%) follow National Comprehensive Cancer Network guidelines for imaging follow-up, while the remainder follow other national guidelines such as those of the Children's Oncology Group, the American Society of Clinical Oncology, or clinical trials. Ninety percent of respondents believe that long-term surveillance in oncology patients is warranted, particularly in patients with breast cancer, melanoma, sarcoma, and pediatric malignancies. The majority of oncologists would consider the use of low-dose CT imaging in specific patient populations: (1) children and young women, (2) those with malignancies that do not routinely metastasize to the liver, and (3) patients undergoing surveillance imaging. Conclusions Cumulative radiation exposure is a concern for patients and oncologists. Among oncologists, there is support for long-term imaging surveillance despite lack of national guidelines. © 2014 American College of Radiology.

Authors
Burke, LMB; Bashir, MR; Neville, AM; Nelson, RC; Jaffe, TA
MLA Citation
Burke, LMB, Bashir, MR, Neville, AM, Nelson, RC, and Jaffe, TA. "Current opinions on medical radiation: A survey of oncologists regarding radiation exposure and dose reduction in oncology patients." Journal of the American College of Radiology 11.5 (January 1, 2014): 490-495.
Source
scopus
Published In
Journal of the American College of Radiology
Volume
11
Issue
5
Publish Date
2014
Start Page
490
End Page
495
DOI
10.1016/j.jacr.2013.08.018

Optimal Timing and Diagnostic Adequacy of Hepatocyte Phase Imaging with Gadoxetate-Enhanced Liver MRI

Rationale and Objectives: To evaluate clinical and imaging features associated with adequacy of the hepatocyte phase (HP) in gadoxetate disodium-enhanced liver magnetic resonance imaging (MRI) in patients without chronic liver disease (CLD). Materials and Methods: This was a retrospective institutional review board-approved study of 97 patients who underwent liver MRI examinations with gadoxetate disodium and had no history of CLD. Available late dynamic and HP sequences (3-20 minutes postinjection) were independently analyzed by four radiologists for perceived image adequacy and level of biliary enhancement. Signal intensity ratios (SIRs) of liver/inferior vena cava (IVC), liver/spleen, and liver/muscle were measured. The Spearman ρ and receiver operating characteristic analyses were performed correlating various factors with HP adequacy. A rule for predicting HP adequacy was also derived and tested to determine whether overall examination time could be shortened. Results: A visually adequate HP was observed in 12% of subjects by 10 minutes, 80% by 15 minutes, and 93% by 20 minutes. An SIRliver/IVC > 1.8 was the imaging feature that had the strongest correlation with an adequate HP (ρ = 0.813, P < .001), and was more predictive of adequacy of the HP than the time postinjection (ρ = 0.5, P < .001). The time at which an adequate HP was first observed did not correlate with any tested demographic or laboratory values. Stopping imaging when an SIRliver/IVC > 1.8 would have successfully reduced mean postcontrast time to 15:39 ± 4:02 from 20:00 (P < .001), although maintaining HP adequacy. Conclusions: Most patients without CLD undergoing gadoxetate-enhanced liver MRI achieve adequate HP at 20 minutes. However, a shorter postcontrast stopping time can be used in most patients. © 2014 AUR.

Authors
Bashir, MR; Breault, SR; Braun, R; Do, RK; Nelson, RC; Reeder, SB
MLA Citation
Bashir, MR, Breault, SR, Braun, R, Do, RK, Nelson, RC, and Reeder, SB. "Optimal Timing and Diagnostic Adequacy of Hepatocyte Phase Imaging with Gadoxetate-Enhanced Liver MRI." Academic Radiology 21.6 (January 1, 2014): 726-732.
Source
scopus
Published In
Academic Radiology
Volume
21
Issue
6
Publish Date
2014
Start Page
726
End Page
732
DOI
10.1016/j.acra.2014.02.005

Vascular artifact mimicking thrombosis on mr imaging using ferumoxytol as a contrast agent in abdominal vascular assessment

Purpose To describe an artifact that mimics thrombosis when assessing abdominal vasculature on magnetic resonance (MR) imaging using ferumoxytol in patients with contraindications to gadolinium-based contrast agents and to evaluate factors that may contribute to this artifact. Materials and Methods Three radiologists in consensus retrospectively evaluated 61 abdominal MR imaging examinations using ferumoxytol as an intravenous contrast agent for the presence of an observed artifact that can mimic thrombosis. Patient demographics and contrast agent bolus concentrations were compared with an unpaired Wilcoxon signed rank test. Results An artifact mimicking thrombosis was observed in 30 of 61 examinations, all on the arterial phase sequences. In examinations with this artifact, the average concentration of administered ferumoxytol was greater than in examinations where the artifact was not observed (P <.01). Several additional vascular findings were observed, including portal vein thrombosis (n = 2) and aneurysm (n = 1), renal vein thrombosis (n = 2), abdominal aortic aneurysm (n = 1), abdominal and iliac artery dissection (n = 3), and sequelae of portal hypertension (n = 8). Conclusions Although MR imaging using ferumoxytol as an intravenous contrast agent can be useful in detecting abdominal vascular abnormalities, an artifact mimicking vascular thrombosis was observed in nearly half of the examinations. © 2014 SIR.

Authors
Fananapazir, G; Marin, D; Suhocki, PV; Kim, CY; Bashir, MR
MLA Citation
Fananapazir, G, Marin, D, Suhocki, PV, Kim, CY, and Bashir, MR. "Vascular artifact mimicking thrombosis on mr imaging using ferumoxytol as a contrast agent in abdominal vascular assessment." Journal of Vascular and Interventional Radiology 25.6 (January 1, 2014): 969-976.
Source
scopus
Published In
JVIR: Journal of Vascular and Interventional Radiology
Volume
25
Issue
6
Publish Date
2014
Start Page
969
End Page
976
DOI
10.1016/j.jvir.2013.12.019

Interdependencies of acquisition, detection, and reconstruction techniques on the accuracy of iodine quantification in varying patient sizes employing dual-energy CT

© 2014, European Society of Radiology.Purpose: To assess the impact of patient habitus, acquisition parameters, detector efficiencies, and reconstruction techniques on the accuracy of iodine quantification using dual-source dual-energy CT (DECT). Materials and methods: Two phantoms simulating small and large patients contained 20 iodine solutions mimicking vascular and parenchymal enhancement from saline isodensity to 400 HU and 30 iodine solutions simulating enhancement of the urinary collecting system from 400 to 2,000 HU. DECT acquisition (80/140 kVp and 100/140 kVp) was performed using two DECT systems equipped with standard and integrated electronics detector technologies. DECT raw datasets were reconstructed using filtered backprojection (FBP), and iterative reconstruction (SAFIRE I/V). Results: Accuracy for iodine quantification was significantly higher for the small compared to the large phantoms (9.2 % ± 7.5 vs. 24.3 % ± 26.1, P = 0.0001), the integrated compared to the conventional detectors (14.8 % ± 20.6 vs. 18.8 % ± 20.4, respectively; P = 0.006), and SAFIRE V compared to SAFIRE I and FBP reconstructions (15.2 % ± 18.1 vs. 16.1 % ± 17.6 and 18.9 % ± 20.4, respectively; P ≤ 0.003). A significant synergism was observed when the most effective detector and reconstruction techniques were combined with habitus-adapted dual-energy pairs. Conclusion: In a second-generation dual-source DECT system, the accuracy of iodine quantification can be substantially improved by an optimal choice and combination of acquisition parameters, detector, and reconstruction techniques. Key Points: • Iodine quantification techniques are not immune to error • Systematic deviations between the measured and true iodine concentrations exist • Acquisition parameters, detector efficiencies, and reconstruction techniques impact accuracy of iodine quantification.

Authors
Marin, D; Pratts-Emanuelli, JJ; Mileto, A; Husarik, DB; Bashir, MR; Nelson, RC; Boll, DT
MLA Citation
Marin, D, Pratts-Emanuelli, JJ, Mileto, A, Husarik, DB, Bashir, MR, Nelson, RC, and Boll, DT. "Interdependencies of acquisition, detection, and reconstruction techniques on the accuracy of iodine quantification in varying patient sizes employing dual-energy CT." European Radiology 25.3 (January 1, 2014): 679-686.
Source
scopus
Published In
European Radiology
Volume
25
Issue
3
Publish Date
2014
Start Page
679
End Page
686
DOI
10.1007/s00330-014-3447-8

Retrospective assessment of the utility of an iron-based agent for contrast-enhanced magnetic resonance venography in patients with endstage renal diseases

Purpose To compare abdominopelvic and lower extremity venous enhancement in contrast-enhanced magnetic resonance venography (ceMRV), using iron-based ferumoxytol and gadolinium-based gadofosveset. Materials and Methods This was a Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study. Thirty-four patients were identified who had undergone ceMRV using either ferumoxtyol (Group A, all with chronic renal insufficiency) or gadofosveset (Group B). Two radiologists rated confidence for evaluation of the major abdominopelvic and lower extremity veins from 4 (excellent confidence) to 1 (nondiagnostic). A third radiologist measured signal intensity ratios (SIRs) of venous segments compared with adjacent muscles. Scores were compared using repeated-measures analysis of variance (ANOVA). The medical record was searched for contemporaneous imaging to confirm the ceMRV findings. Results In Group A, 14/225 venous segments were thrombosed, compared with 18/282 in Group B. There was no statistically significant difference between confidence scores (3.79 ± 0.44 vs. 3.85 ± 0.44, P = 0.34) or SIRs (2.40 ± 0.73 vs. 2.38 ± 0.51, P = 0.51) for patent segments in the two groups, nor were confidences scores (3.89 ± 0.29 vs. 3.72 ± 0.46, P = 0.31) or SIRs (0.90 ± 0.12 vs. 0.84 ± 0.19, P = 0.31) significantly different for thrombosed segments. Contemporaneous imaging confirmed ceMRV findings in 227 segments. Conclusion ceMRV can be performed with ferumoxytol, yielding similar image quality to a blood pool gadolinium-based contrast agent. © 2013 Wiley Periodicals, Inc. © 2013 Wiley Periodicals, Inc.

Authors
Bashir, MR; Mody, R; Neville, A; Javan, R; Seaman, D; Kim, CY; Gupta, RT; Jaffe, TA
MLA Citation
Bashir, MR, Mody, R, Neville, A, Javan, R, Seaman, D, Kim, CY, Gupta, RT, and Jaffe, TA. "Retrospective assessment of the utility of an iron-based agent for contrast-enhanced magnetic resonance venography in patients with endstage renal diseases." Journal of Magnetic Resonance Imaging 40.1 (2014): 113-118.
Source
scival
Published In
Journal of Magnetic Resonance Imaging
Volume
40
Issue
1
Publish Date
2014
Start Page
113
End Page
118
DOI
10.1002/jmri.24330

Magnetic resonance contrast agents for liver imaging

Intravenous contrast agents are important in the performance of liver magnetic resonance (MR) imaging. These agents differ in their physical properties. These differences can be exploited to optimize imaging protocols based on indications for examination. Institutional protocols should be designed to take advantage of the variety of available contrast agent types. Important contrast agent properties including relaxivity and biodistribution are discussed in this article. Practitioners administering contrast agents for MR imaging should be familiar with potential safety issues and establish rational safety guidelines based on available data. Precautions in at-risk populations are discussed, and sample institutional guidelines are provided. © 2014.

Authors
Bashir, MR
MLA Citation
Bashir, MR. "Magnetic resonance contrast agents for liver imaging." Magnetic Resonance Imaging Clinics of North America 22.3 (2014): 283-293.
Source
scival
Published In
Magnetic Resonance Imaging Clinics of North America
Volume
22
Issue
3
Publish Date
2014
Start Page
283
End Page
293
DOI
10.1016/j.mric.2014.04.002

CME update: Review articles and commentaries in JMRI

Authors
Bashir, MR; Korosec, FR; Reeder, SB
MLA Citation
Bashir, MR, Korosec, FR, and Reeder, SB. "CME update: Review articles and commentaries in JMRI." Journal of Magnetic Resonance Imaging 40.4 (2014): 778--.
Source
scival
Published In
Journal of Magnetic Resonance Imaging
Volume
40
Issue
4
Publish Date
2014
Start Page
778-
DOI
10.1002/jmri.24670

Computer-aided liver volumetry: performance of a fully-automated, prototype post-processing solution for whole-organ and lobar segmentation based on MDCT imaging

© 2014, Springer Science+Business Media New York.Purpose: To evaluate the performance of a prototype, fully-automated post-processing solution for whole-liver and lobar segmentation based on MDCT datasets. Materials and methods: A polymer liver phantom was used to assess accuracy of post-processing applications comparing phantom volumes determined via Archimedes’ principle with MDCT segmented datasets. For the IRB-approved, HIPAA-compliant study, 25 patients were enrolled. Volumetry performance compared the manual approach with the automated prototype, assessing intraobserver variability, and interclass correlation for whole-organ and lobar segmentation using ANOVA comparison. Fidelity of segmentation was evaluated qualitatively. Results: Phantom volume was 1581.0 ± 44.7 mL, manually segmented datasets estimated 1628.0 ± 47.8 mL, representing a mean overestimation of 3.0%, automatically segmented datasets estimated 1601.9 ± 0 mL, representing a mean overestimation of 1.3%. Whole-liver and segmental volumetry demonstrated no significant intraobserver variability for neither manual nor automated measurements. For whole-liver volumetry, automated measurement repetitions resulted in identical values; reproducible whole-organ volumetry was also achieved with manual segmentation, p<inf>ANOVA</inf> 0.98. For lobar volumetry, automated segmentation improved reproducibility over manual approach, without significant measurement differences for either methodology, p<inf>ANOVA</inf> 0.95–0.99. Whole-organ and lobar segmentation results from manual and automated segmentation showed no significant differences, p<inf>ANOVA</inf> 0.96–1.00. Assessment of segmentation fidelity found that segments I–IV/VI showed greater segmentation inaccuracies compared to the remaining right hepatic lobe segments. Conclusion: Automated whole-liver segmentation showed non-inferiority of fully-automated whole-liver segmentation compared to manual approaches with improved reproducibility and post-processing duration; automated dual-seed lobar segmentation showed slight tendencies for underestimating the right hepatic lobe volume and greater variability in edge detection for the left hepatic lobe compared to manual segmentation.

Authors
Fananapazir, G; Bashir, MR; Marin, D; Boll, DT
MLA Citation
Fananapazir, G, Bashir, MR, Marin, D, and Boll, DT. "Computer-aided liver volumetry: performance of a fully-automated, prototype post-processing solution for whole-organ and lobar segmentation based on MDCT imaging." Abdominal Imaging 40.5 (2014): 1203-1212.
Source
scival
Published In
Abdominal Imaging
Volume
40
Issue
5
Publish Date
2014
Start Page
1203
End Page
1212
DOI
10.1007/s00261-014-0276-9

Re: Renal transplant imaging using magnetic resonance angiography with a nonnephrotoxic contrast agent

Authors
Bashir, MR; Jaffe, TA; Brennan, TV; Patel, UD; Ellis, MJ
MLA Citation
Bashir, MR, Jaffe, TA, Brennan, TV, Patel, UD, and Ellis, MJ. "Re: Renal transplant imaging using magnetic resonance angiography with a nonnephrotoxic contrast agent." December 1, 2013.
PMID
24209546
Source
scopus
Published In
The Journal of Urology
Volume
190
Issue
6
Publish Date
2013
Start Page
2175
DOI
10.1016/j.juro.2013.05.057

Contrast-enhanced free-breathing 3D T1-weighted gradient-echo sequence for hepatobiliary MRI in patients with breath-holding difficulties.

OBJECTIVE: Evaluate the image quality and diagnostic performance of a free-breathing 3D-gradient-echo sequence with radial acquisition (rGRE) compared with a Cartesian breath-hold 3D-GRE (cGRE) sequence on hepatobiliary phase MRI in patients with breath-holding difficulties. METHODS: Twenty-eight consecutive patients (15 males; mean age 61 ± 11.9 years) were analysed in this retrospective IRB-approved study. Breath-holding difficulties during gadoxetate-disodium-enhanced liver MRI manifested as breathing artefacts during dynamic-phase imaging. MRI included axial and coronal cGRE and a radially sampled rGRE sequence during the hepatobiliary phase. Two radiologists independently evaluated cGRE and rGRE images for image quality, liver lesion detection and conspicuity, and bile duct conspicuity on a four-point scale. RESULTS: Liver edge sharpness was significantly higher on rGRE images (P < 0.001). Overall image quality was slightly but significantly higher for rGRE than for cGRE (P < 0.001 and P = 0.039). Bile duct conspicuity scores of rGRE and cGRE were not significantly different. Sensitivity for detection of the 26 liver lesions was similar for rGRE and cGRE (81-77 % and 73-77 %, P = 0.5 and 1.0). Lesion conspicuity scores were significantly higher for rGRE for one reader (P = 0.012). CONCLUSION: In patients with breath-holding difficulties, overall image quality and liver lesion conspicuity on hepatobiliary phase MRI can be improved using the rGRE sequence. KEY POINTS: • Patients with diminished breath-holding capacities present a major challenge in abdominal MRI. • A free-breathing sequence for hepatobiliary-phase MRI can improve image quality. • Further advances are needed to reduce acquisition time of the free-breathing gradient-echo sequence.

Authors
Reiner, CS; Neville, AM; Nazeer, HK; Breault, S; Dale, BM; Merkle, EM; Bashir, MR
MLA Citation
Reiner, CS, Neville, AM, Nazeer, HK, Breault, S, Dale, BM, Merkle, EM, and Bashir, MR. "Contrast-enhanced free-breathing 3D T1-weighted gradient-echo sequence for hepatobiliary MRI in patients with breath-holding difficulties." Eur Radiol 23.11 (November 2013): 3087-3093.
PMID
23732689
Source
pubmed
Published In
European Radiology
Volume
23
Issue
11
Publish Date
2013
Start Page
3087
End Page
3093
DOI
10.1007/s00330-013-2910-2

Is follow-up CT imaging of the chest and abdomen necessary after preoperative neoadjuvant therapy in rectal cancer patients without evidence of metastatic disease at diagnosis?

AIM: Patients with rectal cancer often undergo multiple CT scans prior to surgical resection. We propose that in patients with locally advanced rectal cancer without evidence of metastatic disease at presentation, CT imaging of the chest and abdomen after preoperative neoadjuvant therapy does not change clinical information or surgical management. METHOD: An institutional review board-approved medical record review identified patients with contrast enhanced CT of the chest, abdomen and pelvis alone or in conjunction with (18)F-fluoro-2-deoxy-d-glucose/positron emission tomography imaging for staging of rectal cancer prior to and after neoadjuvant therapy. Eighty-eight patients were included in the study. Scans were reviewed for the presence of metastatic disease on initial and follow-up imaging prior to surgical resection. RESULTS: Seventy-six (86%) of 88 patients had no evidence of metastasis at presentation. None of these patients developed metastatic disease after neoadjuvant therapy. Twelve (14%) had metastases at presentation. No study patient developed metastatic disease in a new organ. CONCLUSION: Imaging after preoperative neoadjuvant therapy in rectal cancer does not change the designation of metastatic disease. Patients with locally advanced rectal adenocarcinoma without evidence of metastases may not benefit from repeat imaging of the chest and abdomen after neoadjuvant therapy.

Authors
Jaffe, TA; Neville, AM; Bashir, MR; Uronis, HE; Thacker, JM
MLA Citation
Jaffe, TA, Neville, AM, Bashir, MR, Uronis, HE, and Thacker, JM. "Is follow-up CT imaging of the chest and abdomen necessary after preoperative neoadjuvant therapy in rectal cancer patients without evidence of metastatic disease at diagnosis?." Colorectal disease : the official journal of the Association of Coloproctology of Great Britain and Ireland 15.11 (November 2013): e654-e658.
PMID
23910050
Source
epmc
Published In
Colorectal Disease
Volume
15
Issue
11
Publish Date
2013
Start Page
e654
End Page
e658
DOI
10.1111/codi.12372

4D-MRI Using Sagittal Acquisition and Body Area as Respiratory Surrogate

Authors
Liu, Y; Chang, Z; Czito, B; Bashir, M; Yin, F; Cai, J
MLA Citation
Liu, Y, Chang, Z, Czito, B, Bashir, M, Yin, F, and Cai, J. "4D-MRI Using Sagittal Acquisition and Body Area as Respiratory Surrogate." October 1, 2013.
Source
wos-lite
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
87
Issue
2
Publish Date
2013
Start Page
S324
End Page
S324

Automated patient-tailored screening of the liver for diffuse steatosis and iron overload using MRI.

OBJECTIVE: The purpose of this article is to validate an automated screening method for evaluation of hepatic steatosis or siderosis. MATERIALS AND METHODS: This was a two-part study, with retrospective and prospective portions. First, 130 consecutive abdominal MRI examinations, including both the automated algorithm and reference standard fat and iron quantification, were retrospectively identified. The algorithm's performance was validated against the reference standard and was compared with the performance of three expert readers. Subsequently, 39 subjects undergoing liver MRI were prospectively identified and enrolled. These subjects were scanned with a protocol where quantification sequences were either performed or not performed on the basis of the recommendation of the algorithm. Total examination time in these subjects was compared with examination times in the 90 subjects from the retrospective cohort who had undergone a similar liver MRI protocol with complete quantification. RESULTS: The automated algorithm was accurate in determining the presence of deposition disease (93.1%), with no significant difference between its conclusions and those of any of the readers (p=0.48-1.0). Use of the algorithm resulted in a small but statistically significant time savings compared with performing quantification in all subjects (28 minutes 56 seconds vs 31 minutes 20 seconds; p<0.05). CONCLUSION: Automated screening for hepatic steatosis and siderosis can be performed in real time during abdominal MRI examinations, can save total scan time compared with always performing quantification, and could serve as a gatekeeper for dedicated quantification sequences.

Authors
Bashir, MR; Zhong, X; Dale, BM; Gupta, RT; Boll, DT; Merkle, EM
MLA Citation
Bashir, MR, Zhong, X, Dale, BM, Gupta, RT, Boll, DT, and Merkle, EM. "Automated patient-tailored screening of the liver for diffuse steatosis and iron overload using MRI." AJR Am J Roentgenol 201.3 (September 2013): 583-588.
PMID
23971450
Source
pubmed
Published In
AJR. American journal of roentgenology
Volume
201
Issue
3
Publish Date
2013
Start Page
583
End Page
588
DOI
10.2214/AJR.12.10051

Gadofosveset-enhanced magnetic resonance angiography of the thoracic vasculature in the equilibrium phase: feasibility and impact of dose.

OBJECTIVE: The objectives of this study were to evaluate the feasibility of gadofosveset-enhanced magnetic resonance angiography (MRA) of the thoracic vasculature in the equilibrium phase and to determine the impact of gadofosveset dose on imaging quality. METHODS: Thirty healthy volunteers were randomized to receive a dose of 0.03, 0.02, or 0.01 mmol/kg of gadofosveset for MRA at 3 T in the equilibrium phase. Two radiologists assessed the central veins, the pulmonary arteries, and the thoracic aorta. Quantitative assessments were also performed. RESULTS: At 0.03 and 0.02 mmol/kg, all vessel segments were rated as adequate. At a dose of 0.01 mmol/kg, less than 10% of vascular segments were collectively rated as inadequate. The signal-to-noise ratio and contrast-to-noise ratio were significantly lower in all segments at 0.01 mmol/kg compared with higher doses. CONCLUSIONS: Gadofosveset-enhanced MRA of the thoracic vessels in the equilibrium phase in healthy volunteers resulted in adequate vessel visualization, even when dose reduction was performed.This trial was registered with clinicaltrials.gov, identifier NCT01431300.

Authors
Kim, CY; Heye, T; Bashir, MR; Gebhard, TA; Merkle, EM
MLA Citation
Kim, CY, Heye, T, Bashir, MR, Gebhard, TA, and Merkle, EM. "Gadofosveset-enhanced magnetic resonance angiography of the thoracic vasculature in the equilibrium phase: feasibility and impact of dose." J Comput Assist Tomogr 37.5 (September 2013): 732-736.
PMID
24045249
Source
pubmed
Published In
Journal of Computer Assisted Tomography
Volume
37
Issue
5
Publish Date
2013
Start Page
732
End Page
736
DOI
10.1097/RCT.0b013e318299dde9

Inter- and intra-rater reproducibility of quantitative dynamic contrast enhanced MRI using TWIST perfusion data in a uterine fibroid model.

PURPOSE: To determine the reproducibility of TWIST-derived (Time-Resolved Angiography with Interleaved Stochastic Trajectories) quantitative dynamic contrast enhanced (DCE) MRI in a uterine fibroid model. MATERIALS AND METHODS: The institutional review board approved this retrospective study. Dynamic contrast-enhanced TWIST datasets from 15 randomly selected 1.5 Tesla pelvic MR studies were postprocessed. Five readers recorded kinetic parameters (K(trans) [volume transfer constant], ve [extracellular extravascular space volume], kep [flux rate constant], iAUC [initial area under the gadolinium-time curve]) of the largest uterine fibroid using three region-of-interest (ROI) selection methods. Measurements were randomized and repeated three times, and measures of reproducibility were calculated. RESULTS: The intra-rater coefficients of variation (CVs, brackets indicate 95% confidence intervals) varied from 4.6% to 7.6% (K(trans) 7.6% [6.1%, 9.1%], kep 7.2% [5.9%, 8.5%], ve 4.6% [3.8%, 5.4%], and iAUC 7.2% [6.1%, 8.3%]). ve was the most reproducible (P < 0.05). Inter-rater reproducibility was significantly (P < 0.05) greater for the large ROI method (range of intraclass correlation coefficients [ICCs] = 0.80-0.98 versus 0.48-0.63 [user-defined ROI] versus 0.41-0.69 [targeted ROI]). The uterine fibroid accounted for the greatest fraction of variance for the large ROI method (range across kinetic parameters: 83-98% versus 56-69% [user-defined ROI] versus 47-74% [targeted ROI]). The reader accounted for the greatest fraction of variance for the user-defined ROI method (0.4-14.1% versus 0.1-3.0% [large ROI] versus <0.1-1.5% [targeted ROI]). CONCLUSION: Changes in TWIST-derived DCE-MRI kinetic parameters of up to 9-15% may be attributable to measurement error. Large DCE-MRI regions of interest are the most reproducible across multiple readers.

Authors
Davenport, MS; Heye, T; Dale, BM; Horvath, JJ; Breault, SR; Feuerlein, S; Bashir, MR; Boll, DT; Merkle, EM
MLA Citation
Davenport, MS, Heye, T, Dale, BM, Horvath, JJ, Breault, SR, Feuerlein, S, Bashir, MR, Boll, DT, and Merkle, EM. "Inter- and intra-rater reproducibility of quantitative dynamic contrast enhanced MRI using TWIST perfusion data in a uterine fibroid model." J Magn Reson Imaging 38.2 (August 2013): 329-335.
PMID
23239041
Source
pubmed
Published In
Journal of Magnetic Resonance Imaging
Volume
38
Issue
2
Publish Date
2013
Start Page
329
End Page
335
DOI
10.1002/jmri.23974

Generating color-coded anatomic muscle maps for correlation of quantitative magnetic resonance imaging analysis with clinical examination in neuromuscular disorders.

INTRODUCTION: Fatty infiltration of muscles may be seen in many neuromuscular disorders, including glycogen storage disease (GSD), muscular dystrophy, and amyotrophic lateral sclerosis. Recording pathologic involvement of musculature in these patients is cumbersome, given marked disease heterogeneity within each individual. We describe a novel method for simplifying this process and present its application in a patient with GSD type IIIa. METHODS: A color-coded visual mapping tool was developed based on a commonly used spreadsheet platform. RESULTS: This tool depicts individual muscle groups as shapes linked to data cells corresponding to quantitative MRI-based measures of fatty infiltration and weakness assessed by physical examination. It allows for rapid evaluation and chronological comparison of all mapped muscle groups on a single graphical sheet, as well as assessment of response to therapy. CONCLUSION: This approach can be applied in any neuromuscular disorder where muscle function is assessed by clinical or imaging scores.

Authors
Javan, R; Horvath, JJ; Case, LE; Austin, S; Corderi, J; Dubrovsky, A; Kishnani, PS; Bashir, MR
MLA Citation
Javan, R, Horvath, JJ, Case, LE, Austin, S, Corderi, J, Dubrovsky, A, Kishnani, PS, and Bashir, MR. "Generating color-coded anatomic muscle maps for correlation of quantitative magnetic resonance imaging analysis with clinical examination in neuromuscular disorders." Muscle Nerve 48.2 (August 2013): 293-295.
PMID
23801454
Source
pubmed
Published In
Muscle and Nerve
Volume
48
Issue
2
Publish Date
2013
Start Page
293
End Page
295
DOI
10.1002/mus.23780

Renal transplant imaging using magnetic resonance angiography with a nonnephrotoxic contrast agent.

BACKGROUND: In renal allograft recipients presenting with graft dysfunction, it is critical to determine the patency of the transplant vasculature to guide clinical management. Conventional modalities such as Doppler ultrasound, contrast-enhanced computed tomography, magnetic resonance angiography (MRA), and noncontrast MRA are each of limited use because of technical factors and toxicity of standard contrast agents. The purpose of this study was to retrospectively review our institutional experience with renal transplant MRA using ferumoxytol (a nonnephrotoxic medication) as a contrast agent and evaluate its use in the assessment of allograft vascular patency in patients with graft dysfunction, either delayed or slow graft function within hours to days after kidney transplantation or acute kidney injury weeks to months after kidney transplantation. METHODS: Sixteen kidney transplant recipients were retrospectively identified who underwent ferumoxytol-enhanced MRA after a nondiagnostic ultrasound for kidney dysfunction after transplantation. Image evaluation was performed by two radiologists, and clinical follow-up data were collected. RESULTS: In 1 of 16 subjects, MRA with ferumoxytol demonstrated complete arterial occlusion of an allograft. In 2 of 16 subjects, MRA detected moderate to severe anastomotic stenoses, which were confirmed at catheter angiography and successfully treated, resulting in the improvement of graft function. In 13 of 16 subjects, MRA demonstrated normal graft vasculature, and an alternative cause of allograft dysfunction was ultimately confirmed. CONCLUSIONS: Our study suggests that ferumoxytol-enhanced MRA may be a novel, safe method to accurately detect graft artery abnormalities in renal transplant recipients without the risk of nephrotoxicity, when transplant ultrasound is nondiagnostic.

Authors
Bashir, MR; Jaffe, TA; Brennan, TV; Patel, UD; Ellis, MJ
MLA Citation
Bashir, MR, Jaffe, TA, Brennan, TV, Patel, UD, and Ellis, MJ. "Renal transplant imaging using magnetic resonance angiography with a nonnephrotoxic contrast agent." Transplantation 96.1 (July 2013): 91-96.
PMID
23680931
Source
epmc
Published In
Transplantation
Volume
96
Issue
1
Publish Date
2013
Start Page
91
End Page
96
DOI
10.1097/tp.0b013e318295464c

MRI assessment of biliary ductal obstruction: is there added value of T1-weighted gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced MR cholangiography?

OBJECTIVE: The goal of the present study was to determine the added value of gadolium-ethoxybenzyl-diethylenetriamine pentaacetic acid (gadoxetate disodium)-enhanced magnetic resonance cholangiography (MRC) to standard liver MRI including T2-weighted MRCP in assessment of biliary ductal obstruction. MATERIALS AND METHODS: Thirty-eight patients (mean age, 48.1 ± 16.7 years) (40 total examinations) who underwent liver MRI (including T2-weighted MRCP and gadoxetate disodium-enhanced MRC) for suspicion of biliary disease were included in this institutional review board-approved, HIPAA-compliant retrospective study. Three blinded radiologists first evaluated MR images without gadoxetate disodium-enhanced MRC for presence and significance of biliary obstruction, underlying cause for obstruction, and confidence in final diagnosis. After inclusion of gadoxetate disodium-enhanced MRC, readers again determined presence and significance of biliary obstruction and confidence in final diagnosis. Reference standard was established using MRI along with ERCP, percutaneous transhepatic cholangiography, intraoperative cholangiography, or a combination thereof. RESULTS: Overall sensitivity across all readers in diagnosing significance of obstruction was 60% without gadoxetate disodium-enhanced MRC and 91% with gadoxetate disodium- enhanced MRC (p < 0.001). Across all readers, assessment of significance of obstruction was changed when adding gadoxetate disodium-enhanced MRC in 40 of 120 cases (33%); significance of obstruction was correctly changed in 35 of 40 cases (87.5%). Biliary obstruction was graded of unknown significance in 27 of 120 cases (22.5%) across all readers when gadoxetate disodium-enhanced MRC was not reviewed. Significance of biliary obstruction was classified correctly after adding gadoxetate disodium-enhanced MRC in 25 of these 27 cases (93%). Confidence in final diagnosis was significantly higher with addition of gadoxetate di-sodium-enhanced MRC for two of three readers (p < 0.003). CONCLUSION: Addition of gadoxetate disodium-enhanced MRC to liver MRI significantly improves sensitivity in assessing significance of biliary obstruction and can improve reader confidence in establishing a final diagnosis. This added information could have a substantial impact in the determination of the most appropriate therapeutic options.

Authors
Reiner, CS; Merkle, EM; Bashir, MR; Walle, NL; Nazeer, HK; Gupta, RT
MLA Citation
Reiner, CS, Merkle, EM, Bashir, MR, Walle, NL, Nazeer, HK, and Gupta, RT. "MRI assessment of biliary ductal obstruction: is there added value of T1-weighted gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced MR cholangiography?." AJR Am J Roentgenol 201.1 (July 2013): W49-W56.
PMID
23789696
Source
pubmed
Published In
AJR. American journal of roentgenology
Volume
201
Issue
1
Publish Date
2013
Start Page
W49
End Page
W56
DOI
10.2214/AJR.12.9332

TU-G-134-01: 4D-MRI Using Body Area as Internal Respiratory Surrogate: Initial Patient Results

Authors
Yang, J; Yin, F; Wang, H; Chang, Z; Czito, B; Bashir, M; Cai, J
MLA Citation
Yang, J, Yin, F, Wang, H, Chang, Z, Czito, B, Bashir, M, and Cai, J. "TU-G-134-01: 4D-MRI Using Body Area as Internal Respiratory Surrogate: Initial Patient Results." Medical Physics 40.6 (June 2013): 460-460.
Source
crossref
Published In
Medical physics
Volume
40
Issue
6
Publish Date
2013
Start Page
460
End Page
460
DOI
10.1118/1.4815479

TH-C-141-07: T2-Weighted 4D-MRI with Combined Phase and Amplitude Sorting

Authors
Liu, Y; Chang, Z; Czito, B; Bashir, M; Yin, F; Cai, J
MLA Citation
Liu, Y, Chang, Z, Czito, B, Bashir, M, Yin, F, and Cai, J. "TH-C-141-07: T2-Weighted 4D-MRI with Combined Phase and Amplitude Sorting." Medical Physics 40.6 (June 2013): 540-540.
Source
crossref
Published In
Medical physics
Volume
40
Issue
6
Publish Date
2013
Start Page
540
End Page
540
DOI
10.1118/1.4815775

WE-C-116-07: Tumor Enhancement Using Deformable Image Registration for Four-Dimensional Magnetic Resonance Imaging (4D-MRI): A Feasibility Study

Authors
Yang, J; Cai, J; Wang, H; Chang, Z; Czito, B; Bashir, M; Yin, F
MLA Citation
Yang, J, Cai, J, Wang, H, Chang, Z, Czito, B, Bashir, M, and Yin, F. "WE-C-116-07: Tumor Enhancement Using Deformable Image Registration for Four-Dimensional Magnetic Resonance Imaging (4D-MRI): A Feasibility Study." Medical Physics 40.6 (June 2013): 485-485.
Source
crossref
Published In
Medical physics
Volume
40
Issue
6
Publish Date
2013
Start Page
485
End Page
485
DOI
10.1118/1.4815569

Bone marrow enhancement during time-resolved magnetic resonance angiography of the pelvis.

OBJECTIVE: This study aimed to determine whether visible bone marrow enhancement (BME) at pelvic magnetic resonance angiography (MRA) correlates with anemia. METHODS: This is an institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study. Seventy-five female patients with a hemoglobin (Hb) test within 10 days of an MRA examination of the pelvis are included, mean age of 46 years (range, 18-81 years). The BME was graded using a 4-point scale. Fifteen subjects had sufficient imaging data for calculation of quantitative perfusion parameters. Receiver operating characteristic and analysis of covariance were performed for 2 levels of anemia. RESULTS: Enhancement was visually present in 44% (33/75) of cases; 66% (19/29) of anemic subjects (Hb < 12 g/dL), and 30% (14/46) of nonanemic subjects (P = 0.002). Enhancement had a sensitivity of 87.5% and a specificity of 92.5% for the diagnosis of severe anemia (Hb < 10 g/dL); 88% (7/8) of these subjects had moderate to marked enhancement. A high extraction coefficient (Kep) in the iliac crest was associated with anemia, with an area under the curve of the receiver operating characteristic of 0.85 for mild anemia and 0.92 for severe anemia. CONCLUSIONS: Visible BME during time-resolved MRA is common and may be related to anemia.

Authors
Allen, BC; Bashir, MR; Dale, BM; Heye, TJ; Gupta, RT; Merkle, EM
MLA Citation
Allen, BC, Bashir, MR, Dale, BM, Heye, TJ, Gupta, RT, and Merkle, EM. "Bone marrow enhancement during time-resolved magnetic resonance angiography of the pelvis." J Comput Assist Tomogr 37.3 (May 2013): 458-462.
PMID
23674021
Source
pubmed
Published In
Journal of Computer Assisted Tomography
Volume
37
Issue
3
Publish Date
2013
Start Page
458
End Page
462
DOI
10.1097/RCT.0b013e318283d549

Lesion detection and assessment of extrahepatic findings in abdominal MRI using hepatocyte specific contrast agents--comparison of Gd-EOB-DTPA and Gd-BOPTA.

BACKGROUND: To evaluate the contrast agent performance of Gd-EOB-DTPA and Gd-BOPTA for detection and assessment of extrahepatic findings, semi-quantitatively and qualitatively. METHODS: 13 patients with 19 extrahepatic lesions underwent liver MRI with Gd-EOB-DTPA and Gd-BOPTA. Quantitative and relative SNR measurements were performed in each dataset in the arterial and portalvenous phase within the extrahepatic lesion, aorta, inferior vena cava, portal vein, spleen, pancreas and renal cortex. Further, relative CNR measurements were performed. Three readers assessed contrast quality using a five-point scale and choosing the preferred image dataset. Statistical analysis consisted of a Student's t-test with p < 0.05 deemed significant, a weighted kappa statistic for assessment of interobserver variability and an ROC analysis. RESULTS: Mean SNR after injection of Gd-BOPTA was significantly higher compared with Gd-EOB-DTPA for all measurements (p < 0.05). Mean relative SNR was also higher for Gd-BOPTA, but without being statistically significant. There was no significant difference in relative CNR. Interobserver agreement for selection of image preference was moderate (mean weighted kappa 0.485). The area under the curve for the ROC-analysis regarding contrast agent performance was 0.464. CONCLUSION: Even though mean SNR is significantly higher after injection of Gd-BOPTA compared with Gd-EOB-DTPA, there is no significant difference in relative CNR with extrahepatic lesions being assessed equally well. Visual impression may differ after injection of Gd-EOB-DTPA, but does not influence image interpretation. Extrahepatic findings can be assessed similarly to MRI after injection of Gd-BOPTA.

Authors
Ringe, KI; Boll, DT; Husarik, DB; Bashir, MR; Gupta, RT; Merkle, EM
MLA Citation
Ringe, KI, Boll, DT, Husarik, DB, Bashir, MR, Gupta, RT, and Merkle, EM. "Lesion detection and assessment of extrahepatic findings in abdominal MRI using hepatocyte specific contrast agents--comparison of Gd-EOB-DTPA and Gd-BOPTA. (Published online)" BMC Med Imaging 13 (March 18, 2013): 10-.
PMID
23506523
Source
pubmed
Published In
BMC Medical Imaging
Volume
13
Publish Date
2013
Start Page
10
DOI
10.1186/1471-2342-13-10

Reproducibility of dynamic contrast-enhanced MR imaging. Part II. Comparison of intra- and interobserver variability with manual region of interest placement versus semiautomatic lesion segmentation and histogram analysis.

PURPOSE: To compare the inter- and intraobserver variability with manual region of interest (ROI) placement versus that with software-assisted semiautomatic lesion segmentation and histogram analysis with respect to quantitative dynamic contrast material-enhanced (DCE) MR imaging determinations of the volume transfer constant (K(trans)). MATERIALS AND METHODS: The study was approved by the institutional review board and compliant with HIPAA. The requirement to obtain informed consent was waived. Fifteen DCE MR imaging studies of the female pelvis defined the study group. Uterine fibroids were used as a perfusion model. Three varying types of lesion measurements were performed by five readers on each study by using DCE MR imaging perfusion analysis software with manual ROI placement and a semiautomatic lesion segmentation and histogram analysis solution. Intra- and interreader variability of measurements of K(trans) with the different measurement types was calculated. RESULTS: The overall interobserver variability of K(trans) with manual ROI placement (mean, 28.5% ± 9.3) was reduced by 42.5% when the semiautomatic, software-assisted lesion measurement method was used (16.4% ± 6.2). Whole-lesion measurement showed the lowest interobserver variability with both measurement methods (20.1% ± 4.3 with the manual method vs 10.8% ± 2.6 with the semiautomatic method). The overall intrareader variability with the manual ROI method (7.6% ± 10.6) was not significantly different from that with the semiautomatic method (7.3% ± 10.8), but the intraclass correlation coefficient for intrareader reproducibility improved from 0.86 overall with the manual method to 0.99 with the semiautomatic method. CONCLUSION: A semiautomatic lesion segmentation and histogram analysis approach can provide a significant reduction in interobserver variability for DCE MR imaging measurements of K(trans) when compared with manual ROI methods, whereas intraobserver reproducibility is improved to some extent.

Authors
Heye, T; Merkle, EM; Reiner, CS; Davenport, MS; Horvath, JJ; Feuerlein, S; Breault, SR; Gall, P; Bashir, MR; Dale, BM; Kiraly, AP; Boll, DT
MLA Citation
Heye, T, Merkle, EM, Reiner, CS, Davenport, MS, Horvath, JJ, Feuerlein, S, Breault, SR, Gall, P, Bashir, MR, Dale, BM, Kiraly, AP, and Boll, DT. "Reproducibility of dynamic contrast-enhanced MR imaging. Part II. Comparison of intra- and interobserver variability with manual region of interest placement versus semiautomatic lesion segmentation and histogram analysis." Radiology 266.3 (March 2013): 812-821.
PMID
23220891
Source
pubmed
Published In
Radiology
Volume
266
Issue
3
Publish Date
2013
Start Page
812
End Page
821
DOI
10.1148/radiol.12120255

Reproducibility of dynamic contrast-enhanced MR imaging. Part I. Perfusion characteristics in the female pelvis by using multiple computer-aided diagnosis perfusion analysis solutions.

PURPOSE: To test the reproducibility of model-derived quantitative and semiquantitative pharmacokinetic parameters among various commercially available perfusion analysis solutions for dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging. MATERIALS AND METHODS: The study was institutional review board approved and HIPAA compliant, with waiver of informed consent granted. The study group consisted of 15 patients (mean age, 44 years; range, 28-60 years), with 15 consecutive 1.5-T DCE MR imaging studies performed between October 1, 2010, and December 27, 2010, prior to uterine fibroid embolization. Studies were conducted by using variable-flip-angle T1 mapping and four-dimensional, time-resolved MR angiography with interleaved stochastic trajectories. Images from all DCE MR imaging studies were postprocessed with four commercially available perfusion analysis solutions by using a Tofts and Kermode model paradigm. Five observers measured pharmacokinetic parameters (volume transfer constant [K(trans)], v(e) [extracellular extravascular volume fraction], k(ep)[K(trans)/v(e)], and initial area under the gadolinium curve [iAUGC]) three times for each imaging study with each perfusion analysis solution (between March 13, 2011, and September 8, 2011) by using two different region-of-interest methods, resulting in 1800 data points. RESULTS: After normalization of data output, significant differences in mean values were found for the majority of perfusion analysis solution combinations. The within-subject coefficient of variation among perfusion analysis solutions was 48.3%-68.8% for K(trans), 37.2%-60.3% for k(ep), 27.7%-74.1% for v(e), and 25.1%-61.2% for iAUGC. The intraclass correlation coefficient revealed only poor to moderate consistency among pairwise perfusion analysis solution comparisons (K(trans), 0.33-0.65; k(ep), 0.02-0.81; v(e), -0.03 to 0.72; and iAUGC, 0.47-0.78). CONCLUSION: A considerable variability for DCE MR imaging pharmacokinetic parameters (K(trans), k(ep), v(e), iAUGC) was found among commercially available perfusion analysis solutions. Therefore, clinical comparability across perfusion analysis solutions is currently not warranted. Agreement on a postprocessing standard is paramount prior to establishing DCE MR imaging as a widely incorporated biomarker.

Authors
Heye, T; Davenport, MS; Horvath, JJ; Feuerlein, S; Breault, SR; Bashir, MR; Merkle, EM; Boll, DT
MLA Citation
Heye, T, Davenport, MS, Horvath, JJ, Feuerlein, S, Breault, SR, Bashir, MR, Merkle, EM, and Boll, DT. "Reproducibility of dynamic contrast-enhanced MR imaging. Part I. Perfusion characteristics in the female pelvis by using multiple computer-aided diagnosis perfusion analysis solutions." Radiology 266.3 (March 2013): 801-811.
PMID
23220897
Source
pubmed
Published In
Radiology
Volume
266
Issue
3
Publish Date
2013
Start Page
801
End Page
811
DOI
10.1148/radiol.12120278

Quantitative dynamic contrast-enhanced MRI of pelvic and lumbar bone marrow: effect of age and marrow fat content on pharmacokinetic parameter values.

OBJECTIVE: The purpose of this study was to determine the effects of age and fat content on quantitative dynamic contrast-enhanced MRI (DCE-MRI) parameters in the bone marrow of the lumbar spine and pelvis. The interreader reproducibility of this technique will also be assessed. MATERIALS AND METHODS: Forty-three DCE-MRI studies of the female pelvis defined the study group. Quantitative pharmacokinetic perfusion parameters of lumbar and pelvic marrow were analyzed by three readers on a DCE-MRI postprocessing platform. Linear regression analysis was performed to determine the effect of age and marrow fat fraction on the parameters of transfer constant (K(trans)), efflux rate constant (K(ep)), extravascular extracellular space (V(e)), and initial area under the gadolinium curve at 60 seconds (iAUGC(60)). Interreader agreement was assessed by means of intraclass correlation coefficient calculation. RESULTS: A weak but statistically significant correlation was established between both age and fat fraction and the parameters K(trans) (R(2) = 0.14) and K(ep) (R(2) = 0.09). There was also a weak but statistically significant correlation between fat fraction and V(e) (R(2) = 0.116) and iAUGC(60) (R(2) = 0.108), but no correlation between age and these parameters. Intraclass correlation coefficients of parameter measurements by different readers were all greater than 0.7 at the p < 0.05 level. CONCLUSION: Age and fat fraction have small measurable effects on quantitative DCE-MRI parameters in bone marrow. However, given the wide interindividual variation of these parameters, these effects are unlikely to confound changes related to malignancy or treatment. Also of note, there was strong interreader reproducibility of parameter measurements among a range of experience levels, suggesting that the reader-reader experience level may not represent a significant source of variability in bone marrow DCE-MRI.

Authors
Breault, SR; Heye, T; Bashir, MR; Dale, BM; Merkle, EM; Reiner, CS; Faridi, KF; Gupta, RT
MLA Citation
Breault, SR, Heye, T, Bashir, MR, Dale, BM, Merkle, EM, Reiner, CS, Faridi, KF, and Gupta, RT. "Quantitative dynamic contrast-enhanced MRI of pelvic and lumbar bone marrow: effect of age and marrow fat content on pharmacokinetic parameter values." AJR Am J Roentgenol 200.3 (March 2013): W297-W303.
PMID
23436875
Source
pubmed
Published In
AJR. American journal of roentgenology
Volume
200
Issue
3
Publish Date
2013
Start Page
W297
End Page
W303
DOI
10.2214/AJR.12.9080

Hepatocellular carcinoma in a North American population: does hepatobiliary MR imaging with Gd-EOB-DTPA improve sensitivity and confidence for diagnosis?

PURPOSE: To evaluate the value of hepatobiliary phase imaging for detection and characterization of hepatocellular carcinoma (HCC) in liver MRI with Gd-EOB-DTPA, in a North American population. MATERIALS AND METHODS: One hundred MRI examinations performed with the intravenous injection of Gd-EOB-DTPA in patients with cirrhosis were reviewed retrospectively. Nodules were classified as HCC (n = 70), indeterminate (n = 33), or benign (n = 22). Five readers independently reviewed each examination with and without hepatobiliary phase images (HBP). Lesion conspicuity scores were compared between the two readings. Lesion detection, confidence scores, and receiver operating characteristic (ROC) analysis were compared. RESULTS: Lesion detection was slightly improved for all lesion types with the inclusion of the HBP, and was substantially higher for small HCCs (96.0% versus 85.3%). Mean confidence scores for the diagnosis of HCC increased for HCCs overall and each size category (P < 0.001). Diagnostic performance improved with the addition of the HBP (aggregate AROC 87.7% versus 80.0%, P < 0.01), and sensitivity for characterization improved (90.9% versus 78.3%, P < 0.01) while specificity was unchanged. CONCLUSION: Hepatobiliary phase imaging may improve small lesion detection (<1 cm) and characterization of lesions in general, in MRI of the cirrhotic liver with Gd-EOB-DTPA.

Authors
Bashir, MR; Gupta, RT; Davenport, MS; Allen, BC; Jaffe, TA; Ho, LM; Boll, DT; Merkle, EM
MLA Citation
Bashir, MR, Gupta, RT, Davenport, MS, Allen, BC, Jaffe, TA, Ho, LM, Boll, DT, and Merkle, EM. "Hepatocellular carcinoma in a North American population: does hepatobiliary MR imaging with Gd-EOB-DTPA improve sensitivity and confidence for diagnosis?." J Magn Reson Imaging 37.2 (February 2013): 398-406.
PMID
23011874
Source
pubmed
Published In
Journal of Magnetic Resonance Imaging
Volume
37
Issue
2
Publish Date
2013
Start Page
398
End Page
406
DOI
10.1002/jmri.23818

Neoadjuvant Chemoradiation in Patients Undergoing Pancreaticoduodenectomy: Do the Ends Justify the Means?

Authors
Hanna, JM; Penne, K; Rialon, K; Bashir, M; III, BDG; Clary, B; White, R; Pappas, T; Tyler, DS
MLA Citation
Hanna, JM, Penne, K, Rialon, K, Bashir, M, III, BDG, Clary, B, White, R, Pappas, T, and Tyler, DS. "Neoadjuvant Chemoradiation in Patients Undergoing Pancreaticoduodenectomy: Do the Ends Justify the Means?." February 2013.
Source
wos-lite
Published In
Annals of Surgical Oncology
Volume
20
Publish Date
2013
Start Page
S138
End Page
S138

Contrast-enhanced free-breathing 3D T1-weighted gradient-echo sequence for hepatobiliary MRI in patients with breath-holding difficulties

Objective: Evaluate the image quality and diagnostic performance of a free-breathing 3D-gradient-echo sequence with radial acquisition (rGRE) compared with a Cartesian breath-hold 3D-GRE (cGRE) sequence on hepatobiliary phase MRI in patients with breath-holding difficulties. Methods: Twenty-eight consecutive patients (15 males; mean age 61 ± 11.9 years) were analysed in this retrospective IRB-approved study. Breath-holding difficulties during gadoxetate-disodium-enhanced liver MRI manifested as breathing artefacts during dynamic-phase imaging. MRI included axial and coronal cGRE and a radially sampled rGRE sequence during the hepatobiliary phase. Two radiologists independently evaluated cGRE and rGRE images for image quality, liver lesion detection and conspicuity, and bile duct conspicuity on a four-point scale. Results: Liver edge sharpness was significantly higher on rGRE images (P < 0.001). Overall image quality was slightly but significantly higher for rGRE than for cGRE (P < 0.001 and P = 0.039). Bile duct conspicuity scores of rGRE and cGRE were not significantly different. Sensitivity for detection of the 26 liver lesions was similar for rGRE and cGRE (81-77 % and 73-77 %, P = 0.5 and 1.0). Lesion conspicuity scores were significantly higher for rGRE for one reader (P = 0.012). Conclusion: In patients with breath-holding difficulties, overall image quality and liver lesion conspicuity on hepatobiliary phase MRI can be improved using the rGRE sequence. © 2013 European Society of Radiology.

Authors
Reiner, CS; Neville, AM; Nazeer, HK; Breault, S; Dale, BM; Merkle, EM; Bashir, MR
MLA Citation
Reiner, CS, Neville, AM, Nazeer, HK, Breault, S, Dale, BM, Merkle, EM, and Bashir, MR. "Contrast-enhanced free-breathing 3D T1-weighted gradient-echo sequence for hepatobiliary MRI in patients with breath-holding difficulties." European Radiology 23.11 (2013): 3087-3093.
Source
scival
Published In
European Radiology
Volume
23
Issue
11
Publish Date
2013
Start Page
3087
End Page
3093
DOI
10.1007/s00330-013-2910-2

Renal transplant imaging using magnetic resonance angiography with a nonnephrotoxic contrast agent

BACKGROUND: In renal allograft recipients presenting with graft dysfunction, it is critical to determine the patency of the transplant vasculature to guide clinical management. Conventional modalities such as Doppler ultrasound, contrast-enhanced computed tomography, magnetic resonance angiography (MRA), and noncontrast MRA are each of limited use because of technical factors and toxicity of standard contrast agents. The purpose of this study was to retrospectively review our institutional experience with renal transplant MRA using ferumoxytol (a nonnephrotoxic medication) as a contrast agent and evaluate its use in the assessment of allograft vascular patency in patients with graft dysfunction, either delayed or slow graft function within hours to days after kidney transplantation or acute kidney injury weeks to months after kidney transplantation. METHODS: Sixteen kidney transplant recipients were retrospectively identified who underwent ferumoxytol-enhanced MRA after a nondiagnostic ultrasound for kidney dysfunction after transplantation. Image evaluation was performed by two radiologists, and clinical follow-up data were collected. RESULTS: In 1 of 16 subjects, MRA with ferumoxytol demonstrated complete arterial occlusion of an allograft. In 2 of 16 subjects, MRA detected moderate to severe anastomotic stenoses, which were confirmed at catheter angiography and successfully treated, resulting in the improvement of graft function. In 13 of 16 subjects, MRA demonstrated normal graft vasculature, and an alternative cause of allograft dysfunction was ultimately confirmed. CONCLUSIONS: Our study suggests that ferumoxytol-enhanced MRA may be a novel, safe method to accurately detect graft artery abnormalities in renal transplant recipients without the risk of nephrotoxicity, when transplant ultrasound is nondiagnostic. Copyright © 2013 by Lippincott Williams & Wilkins.

Authors
Bashir, MR; Jaffe, TA; Brennan, TV; Patel, UD; Ellis, MJ
MLA Citation
Bashir, MR, Jaffe, TA, Brennan, TV, Patel, UD, and Ellis, MJ. "Renal transplant imaging using magnetic resonance angiography with a nonnephrotoxic contrast agent." Transplantation 96.1 (2013): 91-96.
Source
scival
Published In
Transplantation
Volume
96
Issue
1
Publish Date
2013
Start Page
91
End Page
96
DOI
10.1097/TP.0b013e318295464c

Generating color-coded anatomic muscle maps for correlation of quantitative magnetic resonance imaging analysis with clinical examination in neuromuscular disorders

Introduction: Fatty infiltration of muscles may be seen in many neuromuscular disorders, including glycogen storage disease (GSD), muscular dystrophy, and amyotrophic lateral sclerosis. Recording pathologic involvement of musculature in these patients is cumbersome, given marked disease heterogeneity within each individual. We describe a novel method for simplifying this process and present its application in a patient with GSD type IIIa. Methods: A color-coded visual mapping tool was developed based on a commonly used spreadsheet platform. Results: This tool depicts individual muscle groups as shapes linked to data cells corresponding to quantitative MRI-based measures of fatty infiltration and weakness assessed by physical examination. It allows for rapid evaluation and chronological comparison of all mapped muscle groups on a single graphical sheet, as well as assessment of response to therapy. Conclusion:This approach can be applied in any neuromuscular disorder where muscle function is assessed by clinical or imaging scores. © 2013 Wiley Periodicals, Inc.

Authors
Javan, R; Horvath, JJ; Case, LE; Austin, S; Corderi, J; Dubrovsky, A; Kishnani, PS; Bashir, MR
MLA Citation
Javan, R, Horvath, JJ, Case, LE, Austin, S, Corderi, J, Dubrovsky, A, Kishnani, PS, and Bashir, MR. "Generating color-coded anatomic muscle maps for correlation of quantitative magnetic resonance imaging analysis with clinical examination in neuromuscular disorders." Muscle and Nerve 48.2 (2013): 293-295.
Source
scival
Published In
Muscle and Nerve
Volume
48
Issue
2
Publish Date
2013
Start Page
293
End Page
295
DOI
10.1002/mus.23780

The evolving landscape of self-assessment continuing medical education (SA-CME)

Authors
Bashir, MR; Leiner, T; Reeder, SB
MLA Citation
Bashir, MR, Leiner, T, and Reeder, SB. "The evolving landscape of self-assessment continuing medical education (SA-CME)." Journal of Magnetic Resonance Imaging 38.3 (2013): 509-510.
PMID
23996661
Source
scival
Published In
Journal of Magnetic Resonance Imaging
Volume
38
Issue
3
Publish Date
2013
Start Page
509
End Page
510
DOI
10.1002/jmri.24344

Impact of precontrast T10 relaxation times on dynamic contrast-enhanced MRI pharmacokinetic parameters: T10 mapping versus a fixed T10 reference value

Authors
Heye, T; Boll, DT; Reiner, CS; Bashir, MR; Dale, BM; Merkle, EM
MLA Citation
Heye, T, Boll, DT, Reiner, CS, Bashir, MR, Dale, BM, and Merkle, EM. "Impact of precontrast T10 relaxation times on dynamic contrast-enhanced MRI pharmacokinetic parameters: T10 mapping versus a fixed T10 reference value." Journal of Magnetic Resonance Imaging (2013).
PMID
25006630
Source
scopus
Published In
Journal of Magnetic Resonance Imaging
Publish Date
2013

Bulbar muscle weakness and fatty lingual infiltration in glycogen storage disorder type IIIa.

Glycogen storage disorder type III (GSD III) is a rare autosomal recessive disorder resulting from a deficiency of glycogen debranching enzyme, critical in cytosolic glycogen degradation. GSD IIIa, the most common form of GSD III, primarily affects the liver, cardiac muscle, and skeletal muscle. Although skeletal muscle weakness occurs commonly in GSD IIIa, bulbar muscle involvement has not been previously reported. Here we present three GSD IIIa patients with clinical evidence of bulbar weakness based on instrumental assessment of lingual strength. Dysarthria and/or dysphagia, generally mild in severity, were evident in all three individuals. One patient also underwent correlative magnetic resonance imaging (MRI) which was remarkable for fatty infiltration at the base of the intrinsic tongue musculature, as well as abnormal expansion of the fibro-fatty lingual septum. Additionally, we provide supportive evidence of diffuse glycogen infiltration of the tongue at necropsy in a naturally occurring canine model of GSD IIIa. While further investigation in a larger group of patients with GSD III is needed to determine the incidence of bulbar muscle involvement in this condition and whether it occurs in GSD IIIb, clinical surveillance of lingual strength is recommended.

Authors
Horvath, JJ; Austin, SL; Jones, HN; Drake, EJ; Case, LE; Soher, BJ; Bashir, MR; Kishnani, PS
MLA Citation
Horvath, JJ, Austin, SL, Jones, HN, Drake, EJ, Case, LE, Soher, BJ, Bashir, MR, and Kishnani, PS. "Bulbar muscle weakness and fatty lingual infiltration in glycogen storage disorder type IIIa." Mol Genet Metab 107.3 (November 2012): 496-500.
PMID
23062577
Source
pubmed
Published In
Molecular Genetics and Metabolism
Volume
107
Issue
3
Publish Date
2012
Start Page
496
End Page
500
DOI
10.1016/j.ymgme.2012.09.025

Effectiveness of a breath-hold monitoring system in improving the reproducibility of different breath-hold positions in multiphasic CT imaging.

This study tests whether the utilization of an electronic breath-hold monitoring device improves breath-hold reproducibility during computed tomographic (CT) scanning. Two cohorts of 40 patients underwent dual-phase abdominal CT scans, either with a breath-hold monitoring device or with the standard breath-holding technique. Two blinded readers measured the differences in diaphragmatic position between phases. There was no statistical difference in diaphragmatic position (P=.14) between the monitored (8.5±11.5 mm) and control (5.6±5.2 mm) cohorts. Ten percent of patients from the monitored cohort had greater than 20 mm of deviation, versus 0%-2.5% for the control cohort. Reproduction of breath-holding position remains challenging, even with a monitoring system.

Authors
Grimm, LJ; Feuerlein, S; Bashir, M; Nelson, RC
MLA Citation
Grimm, LJ, Feuerlein, S, Bashir, M, and Nelson, RC. "Effectiveness of a breath-hold monitoring system in improving the reproducibility of different breath-hold positions in multiphasic CT imaging." Clin Imaging 36.6 (November 2012): 754-757.
PMID
23154005
Source
pubmed
Published In
Clinical Imaging
Volume
36
Issue
6
Publish Date
2012
Start Page
754
End Page
757
DOI
10.1016/j.clinimag.2012.01.040

Iodine quantification using dual-energy multidetector computed tomography imaging: phantom study assessing the impact of iterative reconstruction schemes and patient habitus on accuracy.

PURPOSE: The aim of this study was to assess the accuracy of iodine quantification based on spectral dual-energy computed tomography (DECT) extraction with additional noise reduction using iterative reconstruction in simulated optimal and obese patient environments. MATERIALS AND METHODS: Two custom-designed DECT phantoms were containing 10 vials with iodine concentrations representing arterial/parenchymal enhancement ranging from water isodensity to -150 Hounsfield units and, in addition, 40 vials simulating enhancement seen in nondiluted thoracic inlet vasculature and urinary bladder/renal collecting systems of up to -2000 Hounsfield units.Dual-energy computed tomography acquisition was performed using a dual-source scanner at 140 kVp/90 mAs and 80 kVp/495 mAs. Backprojection-based soft tissue kernels and corresponding iteratively reconstructed kernels generated dual-energy series used for iodine extraction.Fractional variations between known and spectrally determined iodine concentration were calculated for each concentration step; paired t tests evaluated variations between backprojected and iteratively reconstructed data sets for small and obese phantoms. Bland-Altman plots with regression analyses assessed concentration differences observed in backprojected and iteratively reconstructed data. RESULTS: For backprojected data, mean concentration variations of 8.7% ± 8.4 and 12.2% ± 6.3 were detected in small and large phantoms, respectively, compared with significantly less variation observed in iteratively reconstructed data with 6.1% ± 6.2 and 11.0% ± 6.5, respectively. Dual-energy quantification systematically overestimated concentrations in lower concentration ranges and underestimated concentrations in higher concentration ranges. Regression analyses showed cubic distribution of concentration differences for backprojected (R = 0.697) and linear distribution for iteratively reconstructed data (R = 0.701). CONCLUSION: Spectral DECT-based iodine quantification is able to accurately quantify iodine in phantoms simulating optimal and large patients; iterative reconstruction improves the accuracy of iodine detection. Systematic deviations of the spectrally determined iodine concentrations could potentially be corrected with weighting curves.

Authors
Feuerlein, S; Heye, TJ; Bashir, MR; Boll, DT
MLA Citation
Feuerlein, S, Heye, TJ, Bashir, MR, and Boll, DT. "Iodine quantification using dual-energy multidetector computed tomography imaging: phantom study assessing the impact of iterative reconstruction schemes and patient habitus on accuracy." Invest Radiol 47.11 (November 2012): 656-661.
PMID
22996313
Source
pubmed
Published In
Investigative Radiology
Volume
47
Issue
11
Publish Date
2012
Start Page
656
End Page
661
DOI
10.1097/RLI.0b013e31826585bb

Gradient shimming during magnetic resonance imaging of the liver: comparison of a standard protocol versus a novel reduced protocol.

PURPOSE: The aim of this study was to examine the effect of minimizing prescan adjustments on table time and image quality in magnetic resonance imaging (MRI) of the liver. MATERIALS AND METHODS: This prospective Health Insurance Portability and Accountability Act-compliant study was approved by the institutional review board, and written informed consent was obtained. Ten volunteers were imaged twice using a noncontrast liver MRI protocol consisting of a total of 10 pulse sequences, once with a standard protocol and once with a fixed table position/minimized prescan adjustment protocol (in random order). Total examination time was evaluated according to a Lean Six Sigma framework. Quantitative sequences, including diffusion-weighted imaging with apparent diffusion coefficient, multi-echo Dixon fat percentage, and the transverse relaxation time, were evaluated and compared between the two protocols. Two experienced readers, blinded to the protocol used, compared image quality between the two protocols. RESULTS: The average number of prescan adjustment steps per examination was reduced from 58.0 to 22.1 using the minimal shimming protocol compared with the normal shimming protocol (P < 0.001). Mean business value added time (scan preparatory time) was reduced by 58% (3 minutes 3 seconds vs 7 minutes 13 seconds), whereas mean total examination time was 20% lower (18 minutes 13 seconds vs 22 minutes 48 seconds, P < 0.001). Quantitative measures obtained using the two protocols were equivalent, and neither reader detected a significant difference in subjective image quality. CONCLUSION: Fixing table position minimizes prescan adjustments and reduces total table time in liver MRI without adversely affecting image quality.

Authors
Bashir, MR; Dale, BM; Gupta, RT; Horvath, JJ; Boll, DT; Merkle, EM
MLA Citation
Bashir, MR, Dale, BM, Gupta, RT, Horvath, JJ, Boll, DT, and Merkle, EM. "Gradient shimming during magnetic resonance imaging of the liver: comparison of a standard protocol versus a novel reduced protocol." Invest Radiol 47.9 (September 2012): 524-529.
PMID
22864376
Source
pubmed
Published In
Investigative Radiology
Volume
47
Issue
9
Publish Date
2012
Start Page
524
End Page
529
DOI
10.1097/RLI.0b013e31825a8e5b

Improved aortic enhancement in CT angiography using slope-based triggering with table speed optimization: a pilot study.

To assess whether a scan triggering technique based on the slope of the time-attenuation curve combined with table speed optimization may improve arterial enhancement in aortic CT angiography compared to conventional threshold-based triggering techniques. Measurements of arterial enhancement were performed in a physiologic flow phantom over a range of simulated cardiac outputs (2.2-8.1 L/min) using contrast media boluses of 80 and 150 mL injected at 4 mL/s. These measurements were used to construct computer models of aortic attenuation in CT angiography, using cardiac output, aortic diameter, and CT table speed as input parameters. In-plane enhancement was calculated for normal and aneurysmal aortic diameters. Calculated arterial enhancement was poor (<150 HU) along most of the scan length using the threshold-based triggering technique for low cardiac outputs and the aneurysmal aorta model. Implementation of the slope-based triggering technique with table speed optimization improved enhancement in all scenarios and yielded good- (>200 HU; 13/16 scenarios) to excellent-quality (>300 HU; 3/16 scenarios) enhancement in all cases. Slope-based triggering with table speed optimization may improve the technical quality of aortic CT angiography over conventional threshold-based techniques, and may reduce technical failures related to low cardiac output and slow flow through an aneurysmal aorta.

Authors
Bashir, MR; Weber, PW; Husarik, DB; Howle, LE; Nelson, RC
MLA Citation
Bashir, MR, Weber, PW, Husarik, DB, Howle, LE, and Nelson, RC. "Improved aortic enhancement in CT angiography using slope-based triggering with table speed optimization: a pilot study." Int J Cardiovasc Imaging 28.6 (August 2012): 1533-1543.
PMID
21898186
Source
pubmed
Published In
International Journal of Cardiovascular Imaging
Volume
28
Issue
6
Publish Date
2012
Start Page
1533
End Page
1543
DOI
10.1007/s10554-011-9945-8

Radiation dose reduction in abdominal computed tomography during the late hepatic arterial phase using a model-based iterative reconstruction algorithm: how low can we go?

OBJECTIVE: The aim of this study was to compare the image quality of abdominal computed tomography scans in an anthropomorphic phantom acquired at different radiation dose levels where each raw data set is reconstructed with both a standard convolution filtered back projection (FBP) and a full model-based iterative reconstruction (MBIR) algorithm. MATERIALS AND METHODS: An anthropomorphic phantom in 3 sizes was used with a custom-built liver insert simulating late hepatic arterial enhancement and containing hypervascular liver lesions of various sizes. Imaging was performed on a 64-section multidetector-row computed tomography scanner (Discovery CT750 HD; GE Healthcare, Waukesha, WI) at 3 different tube voltages for each patient size and 5 incrementally decreasing tube current-time products for each tube voltage. Quantitative analysis consisted of contrast-to-noise ratio calculations and image noise assessment. Qualitative image analysis was performed by 3 independent radiologists rating subjective image quality and lesion conspicuity. RESULTS: Contrast-to-noise ratio was significantly higher and mean image noise was significantly lower on MBIR images than on FBP images in all patient sizes, at all tube voltage settings, and all radiation dose levels (P < 0.05). Overall image quality and lesion conspicuity were rated higher for MBIR images compared with FBP images at all radiation dose levels. Image quality and lesion conspicuity on 25% to 50% dose MBIR images were rated equal to full-dose FBP images. CONCLUSION: This phantom study suggests that depending on patient size, clinically acceptable image quality of the liver in the late hepatic arterial phase can be achieved with MBIR at approximately 50% lower radiation dose compared with FBP.

Authors
Husarik, DB; Marin, D; Samei, E; Richard, S; Chen, B; Jaffe, TA; Bashir, MR; Nelson, RC
MLA Citation
Husarik, DB, Marin, D, Samei, E, Richard, S, Chen, B, Jaffe, TA, Bashir, MR, and Nelson, RC. "Radiation dose reduction in abdominal computed tomography during the late hepatic arterial phase using a model-based iterative reconstruction algorithm: how low can we go?." Invest Radiol 47.8 (August 2012): 468-474.
PMID
22717881
Source
pubmed
Published In
Investigative Radiology
Volume
47
Issue
8
Publish Date
2012
Start Page
468
End Page
474
DOI
10.1097/RLI.0b013e318251eafd

Hepatobiliary-Specific MR Contrast Agents: Is There Added Value of T1-Weighted MR Cholangiography in the Assessment of Biliary Ductal Obstruction?

Authors
Reiner, C; Gupta, R; Bashir, M; Walle, N; Nazeer, H; Merkle, E
MLA Citation
Reiner, C, Gupta, R, Bashir, M, Walle, N, Nazeer, H, and Merkle, E. "Hepatobiliary-Specific MR Contrast Agents: Is There Added Value of T1-Weighted MR Cholangiography in the Assessment of Biliary Ductal Obstruction?." May 2012.
Source
wos-lite
Published In
AJR. American journal of roentgenology
Volume
198
Issue
5
Publish Date
2012

MDCT evaluation of the pancreas: nuts and bolts.

Multidetector-row CT (MDCT) imaging of the pancreas has important roles in diagnosis, staging, and treatment monitoring of a vast array of pancreatic diseases. Optimizing MDCT protocols not only requires an understanding of expected pathologies but also must take into account cumulative radiation dose considerations.

Authors
Bashir, MR; Gupta, RT
MLA Citation
Bashir, MR, and Gupta, RT. "MDCT evaluation of the pancreas: nuts and bolts." Radiol Clin North Am 50.3 (May 2012): 365-377. (Review)
PMID
22560686
Source
pubmed
Published In
Radiologic Clinics of North America
Volume
50
Issue
3
Publish Date
2012
Start Page
365
End Page
377
DOI
10.1016/j.rcl.2012.03.012

Automated liver sampling using a gradient dual-echo Dixon-based technique.

Magnetic resonance spectroscopy of the liver requires input from a physicist or physician at the time of acquisition to insure proper voxel selection, while in multiecho chemical shift imaging, numerous regions of interest must be manually selected in order to ensure analysis of a representative portion of the liver parenchyma. A fully automated technique could improve workflow by selecting representative portions of the liver prior to human analysis. Complete volumes from three-dimensional gradient dual-echo acquisitions with two-point Dixon reconstruction acquired at 1.5 and 3 T were analyzed in 100 subjects, using an automated liver sampling algorithm, based on ratio pairs calculated from signal intensity image data as fat-only/water-only and log(in-phase/opposed-phase) on a voxel-by-voxel basis. Using different gridding variations of the algorithm, the average correct liver volume samples ranged from 527 to 733 mL. The average percentage of sample located within the liver ranged from 95.4 to 97.1%, whereas the average incorrect volume selected was 16.5-35.4 mL (2.9-4.6%). Average run time was 19.7-79.0 s. The algorithm consistently selected large samples of the hepatic parenchyma with small amounts of erroneous extrahepatic sampling, and run times were feasible for execution on an MRI system console during exam acquisition.

Authors
Bashir, MR; Dale, BM; Merkle, EM; Boll, DT
MLA Citation
Bashir, MR, Dale, BM, Merkle, EM, and Boll, DT. "Automated liver sampling using a gradient dual-echo Dixon-based technique." Magn Reson Med 67.5 (May 2012): 1469-1477.
PMID
22190284
Source
pubmed
Published In
Magnetic Resonance in Medicine
Volume
67
Issue
5
Publish Date
2012
Start Page
1469
End Page
1477
DOI
10.1002/mrm.23123

Liver MRI in the hepatocyte phase with gadolinium-EOB-DTPA: does increasing the flip angle improve conspicuity and detection rate of hypointense lesions?

PURPOSE: To compare conspicuity and detection rate of hypointense lesions on T1-weighted (T1w) gradient echo (GRE) sequences with low and high flip angles (FA) in hepatocyte phase magnetic resonance imaging (MRI) using gadoxetate disodium. MATERIALS AND METHODS: This Health Insurance Portability and Accountability Act (HIPAA)-compliant study was Institutional Review Board (IRB)-approved. The study population consisted of patients with hypointense liver lesions undergoing MRI with gadoxetate disodium, with hepatocyte-phase fat suppressed 3D T1w GRE sequences at both low (10-12°) and high (30-35°) FA. Contrast-to-noise ratios (CNRs) were calculated for liver parenchyma vs. large lesions and common bile duct (CBD) vs. liver. Three radiologists each assigned a conspicuity score (CS) for each lesion detected at low or high FA. Paired Student's t-tests compared the lesion detection (LD) rate using only the hepatocyte phase data set compared with the entire MRI examination, and CS for low and high FA. RESULTS: In all, 57 large and 70 small lesions were identified in 18 patients. Average LD and CS were significantly greater at high FA versus low FA overall (LD 89.0% vs. 79.5%; CS 2.8 vs. 2.2; P < 0.05) and for small lesions (81.4% vs. 65.7%; 2.5 vs. 1.8; P < 0.05). Average liver-to-lesion CNR for large lesions and CBD-to-liver CNR was significantly greater at high FA (P < 0.05). CONCLUSION: Increasing the FA in hepatocyte phase MRI with gadoxetate disodium improves hypointense lesion detection and conspicuity, particularly for small lesions.

Authors
Bashir, MR; Husarik, DB; Ziemlewicz, TJ; Gupta, RT; Boll, DT; Merkle, EM
MLA Citation
Bashir, MR, Husarik, DB, Ziemlewicz, TJ, Gupta, RT, Boll, DT, and Merkle, EM. "Liver MRI in the hepatocyte phase with gadolinium-EOB-DTPA: does increasing the flip angle improve conspicuity and detection rate of hypointense lesions?." J Magn Reson Imaging 35.3 (March 2012): 611-616.
PMID
22034383
Source
pubmed
Published In
Journal of Magnetic Resonance Imaging
Volume
35
Issue
3
Publish Date
2012
Start Page
611
End Page
616
DOI
10.1002/jmri.22850

Assessing disease severity in Pompe disease: the roles of a urinary glucose tetrasaccharide biomarker and imaging techniques.

Defining disease severity in patients with Pompe disease is important for prognosis and monitoring the response to therapies. Current approaches include qualitative and quantitative assessments of the disease burden, and clinical measures of the impact of the disease on affected systems. The aims of this manuscript were to review a noninvasive urinary glucose tetrasaccharide biomarker of glycogen storage, and to discuss advances in imaging techniques for determining the disease burden in Pompe disease. The glucose tetrasaccharide, Glcα1-6Glcα1-4Glcα1-4Glc (Glc(4) ), is a glycogen-derived limit dextrin that correlates with the extent of glycogen accumulation in skeletal muscle. As such, it is more useful than traditional biomarkers of tissue damage, such as CK and AST, for monitoring the response to enzyme replacement therapy in patients with Pompe disease. Glc(4) is also useful as an adjunctive diagnostic test for Pompe disease when performed in conjunction with acid alpha-glucosidase activity measurements. Review of clinical records of 208 patients evaluated for Pompe disease by this approach showed Glc(4) had 94% sensitivity and 84% specificity for Pompe disease. We propose Glc(4) is useful as an overall measure of disease burden, but does not provide information on the location and distribution of excess glycogen accumulation. In this manuscript we also review magnetic resonance spectroscopy and imaging techniques as alternative, noninvasive tools for quantifying glycogen and detailing changes, such as fibrofatty muscle degeneration, in specific muscle groups in Pompe disease. These techniques show promise as a means of monitoring disease progression and the response to treatment in Pompe disease. © 2012 Wiley Periodicals, Inc.

Authors
Young, SP; Piraud, M; Goldstein, JL; Zhang, H; Rehder, C; Laforet, P; Kishnani, PS; Millington, DS; Bashir, MR; Bali, DS
MLA Citation
Young, SP, Piraud, M, Goldstein, JL, Zhang, H, Rehder, C, Laforet, P, Kishnani, PS, Millington, DS, Bashir, MR, and Bali, DS. "Assessing disease severity in Pompe disease: the roles of a urinary glucose tetrasaccharide biomarker and imaging techniques." Am J Med Genet C Semin Med Genet 160C.1 (February 15, 2012): 50-58.
PMID
22252961
Source
pubmed
Published In
American Journal of Medical Genetics Part C: Seminars in Medical Genetics
Volume
160C
Issue
1
Publish Date
2012
Start Page
50
End Page
58
DOI
10.1002/ajmg.c.31320

Assessing disease severity in Pompe disease: The roles of a urinary glucose tetrasaccharide biomarker and imaging techniques

Authors
Young, SP; Piraud, M; Goldstein, JL; Zhang, H; Rehder, C; Laforet, P; Kishnani, PS; Millington, DS; Bashir, MR; Bali, DS
MLA Citation
Young, SP, Piraud, M, Goldstein, JL, Zhang, H, Rehder, C, Laforet, P, Kishnani, PS, Millington, DS, Bashir, MR, and Bali, DS. "Assessing disease severity in Pompe disease: The roles of a urinary glucose tetrasaccharide biomarker and imaging techniques." AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 160C.1 (February 15, 2012): 50-58.
Source
wos-lite
Published In
American Journal of Medical Genetics Part C: Seminars in Medical Genetics
Volume
160C
Issue
1
Publish Date
2012
Start Page
50
End Page
58
DOI
10.1002/ajm.31320

Hepatic MR imaging for in vivo differentiation of steatosis, iron deposition and combined storage disorder: single-ratio in/opposed phase analysis vs. dual-ratio Dixon discrimination.

OBJECTIVE: To assess whether in vivo dual-ratio Dixon discrimination can improve detection of diffuse liver disease, specifically steatosis, iron deposition and combined disease over traditional single-ratio in/opposed phase analysis. METHODS: Seventy-one patients with biopsy-proven (17.7 ± 17.0 days) hepatic steatosis (n = 16), iron deposition (n = 11), combined deposition (n = 3) and neither disease (n = 41) underwent MR examinations. Dual-echo in/opposed-phase MR with Dixon water/fat reconstructions were acquired. Analysis consisted of: (a) single-ratio hepatic region-of-interest (ROI)-based assessment of in/opposed ratios; (b) dual-ratio hepatic ROI assessment of in/opposed and fat/water ratios; (c) computer-aided dual-ratio assessment evaluating all hepatic voxels. Disease-specific thresholds were determined; statistical analyses assessed disease-dependent voxel ratios, based on single-ratio (a) and dual-ratio (b and c) techniques. RESULTS: Single-ratio discrimination succeeded in identifying iron deposition (I/O(Ironthreshold)<0.88) and steatosis (I/O(Fatthreshold>1.15)) from normal parenchyma, sensitivity 70.0%; it failed to detect combined disease. Dual-ratio discrimination succeeded in identifying abnormal hepatic parenchyma (F/W(Normalthreshold)>0.05), sensitivity 96.7%; logarithmic functions for iron deposition (I/O(Irondiscriminator)e((F/W(Fat)-0.01)/0.48)) differentiated combined from isolated diseases, sensitivity 100.0%; computer-aided dual-ratio analysis was comparably sensitive but less specific, 90.2% vs. 97.6%. CONCLUSION: MR two-point-Dixon imaging using dual-ratio post-processing based on in/opposed and fat/water ratios improved in vivo detection of hepatic steatosis, iron deposition, and combined storage disease beyond traditional in/opposed analysis.

Authors
Bashir, MR; Merkle, EM; Smith, AD; Boll, DT
MLA Citation
Bashir, MR, Merkle, EM, Smith, AD, and Boll, DT. "Hepatic MR imaging for in vivo differentiation of steatosis, iron deposition and combined storage disorder: single-ratio in/opposed phase analysis vs. dual-ratio Dixon discrimination." Eur J Radiol 81.2 (February 2012): e101-e109.
PMID
21330083
Source
pubmed
Published In
European Journal of Radiology
Volume
81
Issue
2
Publish Date
2012
Start Page
e101
End Page
e109
DOI
10.1016/j.ejrad.2011.01.067

Contrast-enhanced magnetic resonance angiography: first-pass arterial enhancement as a function of gadolinium-chelate concentration, and the saline chaser volume and injection rate.

OBJECTIVE: To evaluate the effect of the contrast medium (CM) concentration and the saline chaser volume and injection rate on first-pass aortic enhancement characteristics in contrast-enhanced magnetic resonance angiography using a physiologic flow phantom. MATERIALS AND METHODS: Imaging was performed on a 3.0-T magnetic resonance system (MAGNETOM Trio, Siemens Healthcare Solutions, Inc, Erlangen, Germany) using a 2-dimensional fast low angle shot T1-weighted sequence (repetition time, 500 milliseconds; echo time, 1.23 milliseconds; flip angle, 8 degrees; 1 frame/s × 60 seconds). The following CM concentrations injected at 2 mL/s were used with 3 different contrast agents (gadolinium [Gd]-BOPTA, Gd-HP-DO3A, Gd-DTPA): 20 mL of undiluted CM (100%) and 80%, 40%, 20%, 10%, 5%, and 2.5% of the full amount, all diluted in saline to a volume of 20 mL to ensure equal bolus volume. The CM was followed by saline chasers of 20 to 60 mL injected at 2 mL/s and 6 mL/s. Aortic signal intensity (SI) was measured, and normalized SI versus time (SI/Tn) curves were generated. The maximal SI (SI(max)), bolus length, and areas under the SI/Tn curve were calculated. RESULTS: Decreasing the CM concentration from 100% to 40% resulted in a decrease of SI(max) to 86.1% (mean). Further decreasing the CM concentration to 2.5% decreased SI(max) to 5.1% (mean). Altering the saline chaser volume had no significant effect on SI(max). Increasing the saline chaser injection rate had little effect (mean increase, 2.2%) on SI(max) when using ≥40% of CM. There was a larger effect (mean increase, 19.6%) when ≤20% of CM were used. Bolus time length was significantly shorter (P < 0.001), and area under the SI/T(n) curve was significantly smaller (P < 0.01) for the CM protocols followed by a saline chaser injected at 6 mL/s compared with a saline chaser injected at 2 mL/s. CONCLUSION: With 40% of CM and a fast saline chaser, SImax close to that with undiluted CM can be achieved. An increased saline chaser injection rate has a more pronounced effect on aortic enhancement characteristics at lower CM concentrations than at higher CM concentrations.

Authors
Husarik, DB; Bashir, MR; Weber, PW; Nichols, EB; Howle, LE; Merkle, EM; Nelson, RC
MLA Citation
Husarik, DB, Bashir, MR, Weber, PW, Nichols, EB, Howle, LE, Merkle, EM, and Nelson, RC. "Contrast-enhanced magnetic resonance angiography: first-pass arterial enhancement as a function of gadolinium-chelate concentration, and the saline chaser volume and injection rate." Invest Radiol 47.2 (February 2012): 121-127.
PMID
21934516
Source
pubmed
Published In
Investigative Radiology
Volume
47
Issue
2
Publish Date
2012
Start Page
121
End Page
127
DOI
10.1097/RLI.0b013e3182300603

Diagnostic accuracy of intra-abdominal fluid collection characterization in the era of multidetector computed tomography.

The purpose of this study was to test the hypothesis that with improved technology, the presence of abscess in a postoperative fluid collection may be prospectively made. This is an Institutional Review Board-approved, Health Insurance Portability and Accountability Act-compliant retrospective review of computed tomography (CT)-guided intra-abdominal fluid collection drainages. The diagnostic CT scans of 95 consecutive patients performed on 16- and 64-multidetector CT (MDCT) were reviewed by four readers with varying abdominal imaging expertise. Readers were asked to determine fluid content, to document whether infection was present, and to rate reader confidence for infection. A fifth radiologist reviewed the collections for imaging characteristics. The gold standard for presence of infection was microbiological Gram stain and culture. The logistic regression model showed that both fluid collections containing gas or high attenuation fluid (average CT density 20 or greater Hounsfield units) are significant predictors of infection (P = 0.001). The average sensitivity over the four readers for determining presence of infection was 83.4 per cent and specificity was 39.3 per cent. Even in the era of MDCT, the ability to predict whether or not a fluid collection is infected or not, based on imaging findings alone, is limited. Presence of gas is a strong indicator of infection, but no imaging finding is characteristic of a sterile fluid collection.

Authors
Allen, BC; Barnhart, H; Bashir, M; Nieman, C; Breault, S; Jaffe, TA
MLA Citation
Allen, BC, Barnhart, H, Bashir, M, Nieman, C, Breault, S, and Jaffe, TA. "Diagnostic accuracy of intra-abdominal fluid collection characterization in the era of multidetector computed tomography." Am Surg 78.2 (February 2012): 185-189.
PMID
22369827
Source
pubmed
Published In
American Surgeon
Volume
78
Issue
2
Publish Date
2012
Start Page
185
End Page
189

Effectiveness of a three-dimensional dual gradient echo two-point Dixon technique for the characterization of adrenal lesions at 3 Tesla.

OBJECTIVE: To compare the sensitivity, specificity, and diagnostic accuracy of fat-only datasets reconstructed using a two-point Dixon technique, with corresponding opposed-phase (OP) and in-phase (IP) datasets for characterization of adrenal lesions at 3 Tesla (T). METHODS: Fifty-nine patients (21 male, 38 female) with 66 adrenal lesions (49 adenomas, 17 nonadenomas) underwent 3D dual gradient-echo 3-T adrenal MR imaging with reconstruction of OP/IP and fat/water datasets. Sensitivity, specificity, and diagnostic accuracy were compared between OP/IP datasets, using the signal intensity index (SII), and fat/water datasets, using the fat fraction and fat ratio. Four radiologists qualitatively assessed OP/IP and fat-only datasets for reader confidence in lesion characterization and image quality. RESULTS: There were significant differences between adenomas and nonadenomas with regard to mean SII, fat fraction, and fat ratio (P < 0.001). There was no significant difference in mean diagnostic accuracy among different evaluation methods using OP/IP and fat/water datasets. Mean readers' scores for lesion characterization were significantly higher for adenomas than for nonadenomas using OP/IP and fat-only datasets. There was no significant difference between the two datasets regarding mean readers' scores for image quality. CONCLUSION: Fat-only images can readily differentiate adrenal adenomas from nonadenomas, with diagnostic accuracy comparable to OP/IP images.

Authors
Marin, D; Dale, BM; Bashir, MR; Ziemlewicz, TJ; Ringe, KI; Boll, DT; Merkle, EM
MLA Citation
Marin, D, Dale, BM, Bashir, MR, Ziemlewicz, TJ, Ringe, KI, Boll, DT, and Merkle, EM. "Effectiveness of a three-dimensional dual gradient echo two-point Dixon technique for the characterization of adrenal lesions at 3 Tesla." Eur Radiol 22.1 (January 2012): 259-268.
PMID
21874570
Source
pubmed
Published In
European Radiology
Volume
22
Issue
1
Publish Date
2012
Start Page
259
End Page
268
DOI
10.1007/s00330-011-2244-x

Rate of contrast material extravasations and allergiclike reactions: Effect of extrinsic warming of low-osmolality iodinated CT contrast material to 37° C

Purpose: To retrospectively determine whether extrinsic warming of the low-osmolality contrast material iopamidol to 37°C prior to intravenous administration at computed tomography (CT) affects extravasation and allergic-like reaction rates. Materials and Methods: The need to obtain informed patient consent was waived for this HIPAA-compliant and institutional review board-approved analysis. All adverse events related to the intravenous administration of iopamidol during CT examinations occurring 200 days before (period 1) and 200 days after (period 2) the cessation of extrinsic contrast material warming (37°C) for intravenous injections of less than 6 mL/sec at Duke University Medical Center (Durham, NC) were retrospectively reviewed. Adverse event rates were compared by using x 2 statistics. Results: There were 12 682 injections during period 1(10 831 injections of iopamidol 300 and 1851 injections of iopamidol 370) and 12 138 injections (10 064 injections of iopamidol 300 and 2074 injections of iopamidol 370) during period 2. Adverse event rates for iopamidol 300 were not affected by extrinsic warming (extravasation rates: 0.30% [32 of 10 831] in period 1 vs 0.23% [23 of 10 064] in period 2, P =.64; allergic-like reaction rates: 0.39% [42 of 10 831] in period 1 vs 0.46% [46 of 10 064] in period 2, P =.74; overall adverse events: 0.68% [74 of 10 831] in period 1 vs 0.69% [69 of 10 064] in period 2, P =.99). Discontinuation of extrinsic warming was associated with significantly increased extravasation and overall adverse event rates for iopamidol 370(extravasation rates: 0.27% [five of 1851] vs 0.87% [18 of 2074], P =.05; allergic-like reaction rates: 0.16% [three of 1851] vs 0.39% [eight of 2074], P =.42; overall adverse events: 0.43% [eight of 1851] vs 1.25% [26 of 2074], P =.02). Conclusion: Extrinsic warming (to 37°C) does not appear to affect adverse event rates for intravenous injections of iopamidol 300 of less than 6 mL/sec but is associated with a significant reduction in extravasation and overall adverse event rates for the more viscous iopamidol 370. © RSNA, 2011.

Authors
Davenport, MS; Wang, CL; Bashir, MR; Neville, AM; Paulson, EK
MLA Citation
Davenport, MS, Wang, CL, Bashir, MR, Neville, AM, and Paulson, EK. "Rate of contrast material extravasations and allergiclike reactions: Effect of extrinsic warming of low-osmolality iodinated CT contrast material to 37° C." Radiology 262.2 (2012): 475-484.
PMID
22106356
Source
scival
Published In
Radiology
Volume
262
Issue
2
Publish Date
2012
Start Page
475
End Page
484
DOI
10.1148/radiol.11111282

Challenges in screening for hepatocellular carcinoma in the glycogen storage disease type 1a population.

Authors
Bashir, MR; Merkle, EM; Kishnani, PS
MLA Citation
Bashir, MR, Merkle, EM, and Kishnani, PS. "Challenges in screening for hepatocellular carcinoma in the glycogen storage disease type 1a population." Intern Med 51.13 (2012): 1811-. (Letter)
PMID
22790156
Source
pubmed
Published In
Internal Medicine
Volume
51
Issue
13
Publish Date
2012
Start Page
1811

White paper from the ACR Task Force on Print Media in Radiology.

The rapidly changing technological and business environment in which scientific journals are published will necessitate ongoing reassessment of operations, goals, and priorities. In this white paper, the ACR Task Force on Print Media in Radiology reviews the history and role of print media in radiology; discusses current and anticipated societal, technological, and financial challenges; and explores a variety of strategies to help ensure the relevance of professional society publishing in the future.

Authors
Duszak, R; Haines, GR; Van Duyn Wear, V; Lexa, FJ; Bashir, M; D'Souza, S; Carlos, R; Chen, JY-Y; King, BF; Wald, C
MLA Citation
Duszak, R, Haines, GR, Van Duyn Wear, V, Lexa, FJ, Bashir, M, D'Souza, S, Carlos, R, Chen, JY-Y, King, BF, and Wald, C. "White paper from the ACR Task Force on Print Media in Radiology." J Am Coll Radiol 8.10 (October 2011): 692-702. (Review)
PMID
21962783
Source
pubmed
Published In
Journal of the American College of Radiology
Volume
8
Issue
10
Publish Date
2011
Start Page
692
End Page
702
DOI
10.1016/j.jacr.2011.06.018

Imaging-guided preoperative hookwire localization of nonpalpable extramammary lesions.

OBJECTIVE: Imaging-guided hookwire localization of nonpalpable lesions in the breast is frequently performed preoperatively. Outside the breast, this procedure is useful for planning resection of lesions in anatomic regions without intrinsic landmarks. The purpose of this study was to review an experience with hookwire localization of nonpalpable extramammary lesions. CONCLUSION: Preoperative imaging-guided hookwire localization is a useful technique that allows precise exploration and resection of nonpalpable lesions and increases confidence that the lesions have been entirely resected.

Authors
Brown, KJ; Bashir, MR; Baker, JA; Tyler, DS; Paulson, EK
MLA Citation
Brown, KJ, Bashir, MR, Baker, JA, Tyler, DS, and Paulson, EK. "Imaging-guided preoperative hookwire localization of nonpalpable extramammary lesions." AJR Am J Roentgenol 197.3 (September 2011): W525-W527.
PMID
21862783
Source
pubmed
Published In
AJR. American journal of roentgenology
Volume
197
Issue
3
Publish Date
2011
Start Page
W525
End Page
W527
DOI
10.2214/AJR.10.6176

Global health training in radiology residency programs.

RATIONALE AND OBJECTIVES: To measure perceptions of radiology residents regarding the imaging needs of the developing world and the potential role of an organized global health imaging curriculum during residency training. MATERIALS AND METHODS: An electronic survey was created and then distributed to residents in accredited US radiology residency. RESULTS: Two hundred ninety-four residents responded to the survey. A majority (61%) planned to pursue future international medical aid work, even though a similar proportion (59%) believed that they would be ill-prepared with their current training to pursue this career goal. The vast majority (91%) of respondents stated that their residency program offers no opportunities to participate in global health imaging experiences. Most surveyed residents felt that an organized global health imaging curriculum would improve understanding of basic disease processes (87%) and cost-conscious care (82%), prepare residents for lifelong involvement in global health (80%), and increase interpretative skills in basic radiology modalities (73%). If such a curriculum were available, most (62%) of surveyed residents stated that they would be likely or very likely to participate. Many (58%) believed the availability of such a program would have influenced their choice of residency program; a similar proportion of residents (75%) believed that the availability of a global health imaging curriculum would increase recruitment to the field of radiology. CONCLUSION: Many radiology residents are motivated to acquire global health imaging experience, with most survey respondents planning to participate in global health initiatives. These data demonstrate an imbalance between the level of resident interest and the availability of global health imaging opportunities, and support the need for discussion on how to implement global health imaging training within radiology residency programs.

Authors
Lungren, MP; Horvath, JJ; Welling, RD; Azene, EM; Starikovsky, A; Bashir, MR; Mollura, DJ; Maxfield, C
MLA Citation
Lungren, MP, Horvath, JJ, Welling, RD, Azene, EM, Starikovsky, A, Bashir, MR, Mollura, DJ, and Maxfield, C. "Global health training in radiology residency programs." Acad Radiol 18.6 (June 2011): 782-791.
PMID
21458308
Source
pubmed
Published In
Academic Radiology
Volume
18
Issue
6
Publish Date
2011
Start Page
782
End Page
791
DOI
10.1016/j.acra.2011.02.009

Effect of organ enhancement and habitus on estimation of unenhanced attenuation at contrast-enhanced dual-energy MDCT: concepts for individualized and organ-specific spectral iodine subtraction strategies.

OBJECTIVE: The purpose of this study was to assess whether habitus and organ enhancement influence iodine subtraction and should be incorporated into spectral subtraction algorithms. SUBJECTS AND METHODS: This study included 171 patients. In the unenhanced phase, MDCT was performed with single-energy acquisition (120 kVp, 250 mAs) and in the parenchymal phase with dual-energy acquisitions (80 kVp, 499 mAs; 140 kVp, 126 mAs). Habitus was determined by measuring trunk diameters and calculating circumference. Iodine subtraction was performed with input parameters individualized to muscle, fat, and blood ratio. Attenuation of the liver, pancreas, spleen, kidneys, and aorta was assessed in truly and virtually unenhanced image series. Pearson analysis was performed to correlate habitus with the input parameters. Analysis of truly unenhanced and virtually unenhanced images was performed with the Student t test; magnitude of variation was evaluated with Bland-Altman plots. Correction strategies were derived from organ-specific regression analysis of scatterplots of truly unenhanced and virtually unenhanced attenuation and implemented in a pixel-by-pixel approach. Analysis of individual organ correction and truly unenhanced attenuation was performed with the Student t test. RESULTS: The correlations between habitus and blood ratio (r = 0.694) and attenuation variation of fat at 80 kVp (r = -0.468) and 140 kV (r = -0.454) were confirmed. Although overall mean attenuation differed by no more than 10 HU between truly and virtually unenhanced scans overall, these differences varied by organ and were large in individual patients. Paired comparisons of truly and virtually unenhanced measurements differed significantly for liver, spleen, pancreas, kidneys, and aortic blood pool (p < 0.001 for all comparisons), but paired comparisons of truly unenhanced and individually organ-corrected measurements did not differ when organ- and habitus-based correction strategies were applied (p > 0.38 for all comparisons). CONCLUSION: Habitus and organ enhancement influence virtually unenhanced imaging and should be incorporated into spectral subtraction algorithms.

Authors
Miller, CM; Gupta, RT; Paulson, EK; Neville, AM; Bashir, MR; Merkle, EM; Boll, DT
MLA Citation
Miller, CM, Gupta, RT, Paulson, EK, Neville, AM, Bashir, MR, Merkle, EM, and Boll, DT. "Effect of organ enhancement and habitus on estimation of unenhanced attenuation at contrast-enhanced dual-energy MDCT: concepts for individualized and organ-specific spectral iodine subtraction strategies." AJR Am J Roentgenol 196.5 (May 2011): W558-W564.
PMID
21512045
Source
pubmed
Published In
AJR. American journal of roentgenology
Volume
196
Issue
5
Publish Date
2011
Start Page
W558
End Page
W564
DOI
10.2214/AJR.10.4858

Improved liver lesion conspicuity by increasing the flip angle during hepatocyte phase MR imaging.

OBJECTIVE: One of the advantages of using hepatobiliary contrast agents in liver MRI is the ability to acquire a delayed, "hepatocyte phase" dataset. This phase highlights many types of lesions as hypointense compared with the liver, because of the accumulation of contrast material in functioning hepatocytes and non-retention within most lesions. METHOD: Increasing the flip angle of the T1-weighted pulse sequence used to acquire the hepatocyte phase is a simple parameter change that increases the contrast-to-noise ratio of focal lesions compared with the hepatic parenchyma. RESULT: This technique increases the sensitivity for detection and conspicuity of focal liver lesions. CONCLUSION: High flip angle delayed hepatocyte phase imaging is a useful adjunct to standard enhanced MRI of the liver. It allows for better sensitivity in focal lesion detection, particularly for small lesions. Secondarily, this technique increases the conspicuity of the biliary system, which is an additional benefit of delayed imaging with hepatobiliary contrast agents.

Authors
Bashir, MR; Merkle, EM
MLA Citation
Bashir, MR, and Merkle, EM. "Improved liver lesion conspicuity by increasing the flip angle during hepatocyte phase MR imaging." Eur Radiol 21.2 (February 2011): 291-294.
PMID
20686771
Source
pubmed
Published In
European Radiology
Volume
21
Issue
2
Publish Date
2011
Start Page
291
End Page
294
DOI
10.1007/s00330-010-1917-1

White paper from the ACR task force on print media in radiology

The rapidly changing technological and business environment in which scientific journals are published will necessitate ongoing reassessment of operations, goals, and priorities. In this white paper, the ACR Task Force on Print Media in Radiology reviews the history and role of print media in radiology; discusses current and anticipated societal, technological, and financial challenges; and explores a variety of strategies to help ensure the relevance of professional society publishing in the future. © 2011 American College of Radiology.

Authors
Duszak, R; Haines, GR; Van Duyn Wear, V; Lexa, FJ; Bashir, M; D'Souza, S; Carlos, R; Chen, JY-Y; King, BF; Wald, C
MLA Citation
Duszak, R, Haines, GR, Van Duyn Wear, V, Lexa, FJ, Bashir, M, D'Souza, S, Carlos, R, Chen, JY-Y, King, BF, and Wald, C. "White paper from the ACR task force on print media in radiology." Journal of the American College of Radiology 8.10 (2011): 692-702.
Source
scopus
Published In
Journal of the American College of Radiology
Volume
8
Issue
10
Publish Date
2011
Start Page
692
End Page
702
DOI
10.1016/j.jacr.2011.06.018

Evaluation of Response Criteria in Solid Tumors (RECIST) 1.1: Do New Guidelines Change Disease Status in Patients with Renal Cell Carcinoma

Authors
Ziemlewicz, T; Bashir, M; Moshiri, S; Jaffe, T
MLA Citation
Ziemlewicz, T, Bashir, M, Moshiri, S, and Jaffe, T. "Evaluation of Response Criteria in Solid Tumors (RECIST) 1.1: Do New Guidelines Change Disease Status in Patients with Renal Cell Carcinoma." May 2010.
Source
wos-lite
Published In
AJR. American journal of roentgenology
Volume
194
Issue
5
Publish Date
2010

Endoleaks after endovascular abdominal aortic aneurysm repair: management strategies according to CT findings.

OBJECTIVE: With increasing use of endovascular techniques for repair of abdominal aortic aneurysms, the prevalence of leakage into excluded aneurysm sacs (endoleaks) as a complication has risen. We will describe and illustrate the imaging findings for endoleaks involving abdominal aortic aneurysms. We will also discuss which types of endoleaks require urgent catheter-based evaluation. CONCLUSION: Radiologists should be familiar with the classification scheme for endoleaks and understand which types of endoleaks require urgent catheter-based evaluation.

Authors
Bashir, MR; Ferral, H; Jacobs, C; McCarthy, W; Goldin, M
MLA Citation
Bashir, MR, Ferral, H, Jacobs, C, McCarthy, W, and Goldin, M. "Endoleaks after endovascular abdominal aortic aneurysm repair: management strategies according to CT findings." AJR Am J Roentgenol 192.4 (April 2009): W178-W186. (Review)
PMID
19304678
Source
pubmed
Published In
AJR. American journal of roentgenology
Volume
192
Issue
4
Publish Date
2009
Start Page
W178
End Page
W186
DOI
10.2214/AJR.08.1593

Changes to resident call and the dilution of education.

Authors
Bashir, MR
MLA Citation
Bashir, MR. "Changes to resident call and the dilution of education." J Am Coll Radiol 6.4 (April 2009): 277-278.
PMID
19327662
Source
pubmed
Published In
Journal of the American College of Radiology
Volume
6
Issue
4
Publish Date
2009
Start Page
277
End Page
278
DOI
10.1016/j.jacr.2008.11.006

Median nerve injury as a result of medial brachial fascial compartment syndrome.

A case of brachial plexus injury after brachial arteriography is reported. Percutaneous catheterization of the brachial artery for angiography and intervention is performed when contraindications for the femoral approach exist. Access-related complications include injuries to the infraclavicular brachial plexus. This is often a result of a hematoma within the medial brachial fascial compartment leading to a compartment syndrome. Early recognition and prompt surgical management is vital to prevent permanent nerve damage.

Authors
Pillai, AK; Bashir, M; Ferral, H; Paruchuri, S; Domkan, A
MLA Citation
Pillai, AK, Bashir, M, Ferral, H, Paruchuri, S, and Domkan, A. "Median nerve injury as a result of medial brachial fascial compartment syndrome." J Vasc Interv Radiol 18.11 (November 2007): 1434-1435.
PMID
18003995
Source
pubmed
Published In
JVIR: Journal of Vascular and Interventional Radiology
Volume
18
Issue
11
Publish Date
2007
Start Page
1434
End Page
1435
DOI
10.1016/j.jvir.2007.07.028
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