Allen Song

Overview:

The research in our lab is concerned with advancing structural and functional MRI methodologies (e.g. fast and high-resolution imaging techniques) for human brain imaging. We also aim to improve our understanding of functional brain signals, including spatiotemporal characterizations of the blood oxygenation level dependent contrast and alternative contrast mechanisms that are more directly linked to the neuronal activities. Additional effort is invested in applying and validating the developed methods to study human functional neuroanatomy.

Positions:

Professor in Radiology

Radiology
School of Medicine

Director of the Center for Brain Imaging and Analysis

Duke-UNC Center for Brain Imaging and Analysis
School of Medicine

Professor in Psychiatry and Behavioral Sciences

Psychiatry & Behavioral Sciences
School of Medicine

Professor in Neurobiology

Neurobiology
School of Medicine

Faculty Network Member of the Duke Institute for Brain Sciences

Duke Institute for Brain Sciences
Institutes and Provost's Academic Units

Member of the Duke Cancer Institute

Duke Cancer Institute
School of Medicine

Education:

Ph.D. 1995

Medical College of Wisconsin

Visiting Fellow, Laboratory Of Brain And Cognition

National Institutes of Health

Assistant Professor of Radiology, Tenure Track, Radiology

Emory University

Grants:

High Fidelity Diffusion MRI for Children with Cerebral Palsy in Stem Cell Therapy

Administered By
Duke-UNC Center for Brain Imaging and Analysis
Awarded By
National Institutes of Health
Role
Principal Investigator
Start Date
End Date

Role of cannabis on HIV-related cognitive impairment: a brain connectomics study

Administered By
Psychiatry & Behavioral Sciences, Addiction
Awarded By
National Institutes of Health
Role
Co Investigator
Start Date
End Date

Neuroimaging of Visual Attention in Aging

Administered By
Psychiatry & Behavioral Sciences, Geriatric Behavioral Health
Awarded By
National Institutes of Health
Role
Co Investigator
Start Date
End Date

MRI data fusion to investigate effects of drug abuse on HIV neurological complications

Administered By
Psychiatry & Behavioral Sciences, Addiction
Awarded By
National Institutes of Health
Role
Co Investigator
Start Date
End Date

NCANDA Research Project Site: Duke

Administered By
Psychiatry, Child & Family Mental Health & Developmental Neuroscience
Awarded By
National Institutes of Health
Role
Collaborator
Start Date
End Date

Publications:

Risk factors for subsequent febrile seizures in the FEBSTAT study.

OBJECTIVES: To identify risk and risk factors for developing a subsequent febrile seizure (FS) in children with a first febrile status epilepticus (FSE) compared to a first simple febrile seizure (SFS). To identify home use of rescue medications for subsequent FS. METHODS: Cases included a first FS that was FSE drawn from FEBSTAT and Columbia cohorts. Controls were a first SFS. Cases and controls were classified according to established FEBSTAT protocols. Cumulative risk for subsequent FS over a 5-year period was compared in FSE versus SFS, and Cox proportional hazards regression was conducted. Separate analysis examined subsequent FS within FSE. The use of rescue medications at home was assessed for subsequent FS. RESULTS: Risk for a subsequent FSE was significantly increased in FSE versus SFS. Any magnetic resonance imaging (MRI) abnormality increased the risk 3.4-fold (p < 0.05), adjusting for age at first FS and FSE and in analyses restricted to children whose first FS was FSE (any MRI abnormality hazard ratio [HR] 2.9, p < 0.05). The risk for a second FS of any type or of subsequent FS lasting >10 min over the 5-year follow-up did not differ in FSE versus SFS. Rectal diazepam was administered at home to 5 (23.8%) of 21 children with subsequent FS lasting ≥10 min. SIGNIFICANCE: Compared to controls, FSE was associated with an increased risk for subsequent FSE, suggesting the propensity of children with an initial prolonged seizure to experience a prolonged recurrence. Any baseline MRI abnormality increased the recurrence risk when FSE was compared to SFS and when FSE was studied alone. A minority of children with a subsequent FS lasting 10 min or longer were treated with rectal diazepam at home, despite receiving prescriptions after the first FSE. This indicates the need to further improve the education of clinicians and parents in order to prevent subsequent FSE.
Authors
Hesdorffer, DC; Shinnar, S; Lax, DN; Pellock, JM; Nordli, DR; Seinfeld, S; Gallentine, W; Frank, LM; Lewis, DV; Shinnar, RC; Bello, JA; Chan, S; Epstein, LG; Moshé, SL; Liu, B; Sun, S; FEBSTAT study team,
MLA Citation
Hesdorffer, Dale C., et al. “Risk factors for subsequent febrile seizures in the FEBSTAT study.Epilepsia, vol. 57, no. 7, July 2016, pp. 1042–47. Pubmed, doi:10.1111/epi.13418.
URI
https://scholars.duke.edu/individual/pub1134150
PMID
27265870
Source
pubmed
Published In
Epilepsia
Volume
57
Published Date
Start Page
1042
End Page
1047
DOI
10.1111/epi.13418

Integrated parallel reception, excitation, and shimming (iPRES).

PURPOSE: To develop a new concept for a hardware platform that enables integrated parallel reception, excitation, and shimming. THEORY: This concept uses a single coil array rather than separate arrays for parallel excitation/reception and B0 shimming. It relies on a novel design that allows a radiofrequency current (for excitation/reception) and a direct current (for B0 shimming) to coexist independently in the same coil. METHODS: Proof-of-concept B0 shimming experiments were performed with a two-coil array in a phantom, whereas B0 shimming simulations were performed with a 48-coil array in the human brain. RESULTS: Our experiments show that individually optimized direct currents applied in each coil can reduce the B0 root-mean-square error by 62-81% and minimize distortions in echo-planar images. The simulations show that dynamic shimming with the 48-coil integrated parallel reception, excitation, and shimming array can reduce the B0 root-mean-square error in the prefrontal and temporal regions by 66-79% as compared with static second-order spherical harmonic shimming and by 12-23% as compared with dynamic shimming with a 48-coil conventional shim array. CONCLUSION: Our results demonstrate the feasibility of the integrated parallel reception, excitation, and shimming concept to perform parallel excitation/reception and B0 shimming with a unified coil system as well as its promise for in vivo applications.
Authors
Han, H; Song, AW; Truong, T-K
MLA Citation
Han, Hui, et al. “Integrated parallel reception, excitation, and shimming (iPRES)..” Magn Reson Med, vol. 70, no. 1, July 2013, pp. 241–47. Pubmed, doi:10.1002/mrm.24766.
URI
https://scholars.duke.edu/individual/pub954797
PMID
23629974
Source
pubmed
Published In
Magn Reson Med
Volume
70
Published Date
Start Page
241
End Page
247
DOI
10.1002/mrm.24766

Distinct value signals in anterior and posterior ventromedial prefrontal cortex.

The core feature of an economic exchange is a decision to trade one good for another, based on a comparison of relative value. Economists have long recognized, however, that the value an individual ascribes to a good during decision making (i.e., their relative willingness to trade for that good) does not always map onto the reward they actually experience. Here, we show that experienced value and decision value are represented in distinct regions of ventromedial prefrontal cortex (VMPFC) during the passive consumption of rewards. Participants viewed two categories of rewards-images of faces that varied in their attractiveness and monetary gains and losses-while being scanned using functional magnetic resonance imaging. An independent market task, in which participants exchanged some of the money that they had earned for brief views of attractive faces, determined the relative decision value associated with each category. We found that activation of anterior VMPFC increased with increasing experienced value, but not decision value, for both reward categories. In contrast, activation of posterior VMPFC predicted each individual's relative decision value for face and monetary stimuli. These results indicate not only that experienced value and decision value are represented in distinct regions of VMPFC, but also that decision value signals are evident even in the absence of an overt choice task. We conclude that decisions are made by comparing neural representations of the value of different goods encoded in posterior VMPFC in a common, relative currency.
Authors
Smith, DV; Hayden, BY; Truong, T-K; Song, AW; Platt, ML; Huettel, SA
MLA Citation
Smith, David V., et al. “Distinct value signals in anterior and posterior ventromedial prefrontal cortex..” J Neurosci, vol. 30, no. 7, Feb. 2010, pp. 2490–95. Pubmed, doi:10.1523/JNEUROSCI.3319-09.2010.
URI
https://scholars.duke.edu/individual/pub736838
PMID
20164333
Source
pubmed
Published In
Journal of Neuroscience
Volume
30
Published Date
Start Page
2490
End Page
2495
DOI
10.1523/JNEUROSCI.3319-09.2010

Endogenous functional CBV contrast revealed by diffusion weighting.

Functional MRI (fMRI) based on the blood oxygenation level dependent (BOLD) contrast often suffers from a lack of specificity because of the vascular spread of oxygenation changes. It is suggested from the optical imaging and animal fMRI literature that cerebral blood volume (CBV) changes are more closely tied to the smaller vessels. As such, fMRI contrast based on CBV changes will have improved spatial specificity to the neuronal activities as they are immediately adjacent to the smaller vessels. In this paper, an endogenous contrast mechanism based on a diffusion weighting strategy that could detect functional CBV changes is presented. Initially, a theoretical framework is presented to model the functional signal changes as a function of CBV under diffusion weighting, which predicts peak CBV sensitivity at various vessel-tissue mixtures. It was found that a b factor over 1500 s/mm(2) would be necessary to achieve dominant CBV contrast. Further, two sets of experimental results are also presented. In the first experiment, diffusion weighting at a set of b factors ranging from 300 to 600 s/mm(2) was used. The results indicated that while the positive activation (predominantly BOLD signal) continued to reduce in magnitude and spatial extent, the negative activation (predominantly CBV signal) remained virtually constant with increasing b factors. The second experiment used a b factor of 1600 s/mm(2) and showed extensive negative activation in the visual cortex and greatly reduced positive activations compared with images with no diffusion weighting. The time course of negative activation showed a faster time to peak and return to baseline than the positive BOLD activity, consistent with the small vessel origin of the signal changes. These results suggest that appropriate diffusion weighting could be used to measure activation related CBV changes.
Authors
Harshbarger, TB; Song, AW
MLA Citation
Harshbarger, Todd B., and Allen W. Song. “Endogenous functional CBV contrast revealed by diffusion weighting..” Nmr Biomed, vol. 19, no. 8, Dec. 2006, pp. 1020–27. Pubmed, doi:10.1002/nbm.1067.
URI
https://scholars.duke.edu/individual/pub686695
PMID
16894639
Source
pubmed
Published In
Nmr in Biomedicine
Volume
19
Published Date
Start Page
1020
End Page
1027
DOI
10.1002/nbm.1067

FMRI signal source analysis using diffusion-weighted spiral-in acquisition.

Despite the tremendous growth in functional magnetic resonance imaging (fMRI), susceptibility induced static field inhomogeneity at air/tissue interface have limited the study of ventral brain regions engaged in object recognition and other processes. Furthermore, the spatial extent of fMRI activations in this region may be obscured by contribution of large vessels distant from the precipitating neural events. In this report, a diffusion weighted spiral-in image acquisition was employed to recover fMRI signal in the ventral brain during object recognition with high temporal resolution, as well as to suppress large vessel contributions. The combined methodology of the ventral signal recovery and vascular signal reduction can thus be advantageous for fMRI investigations at the statically inhomogeneous areas.
Authors
Song, A; Emberger, K; Michelich, C; McCarthy, G
MLA Citation
Song, Allen, et al. “FMRI signal source analysis using diffusion-weighted spiral-in acquisition..” Conference Proceedings : ... Annual International Conference of the Ieee Engineering in Medicine and Biology Society. Ieee Engineering in Medicine and Biology Society. Annual Conference, vol. 6, Jan. 2004, pp. 4417–20. Epmc, doi:10.1109/iembs.2004.1404228.
URI
https://scholars.duke.edu/individual/pub799562
PMID
17271285
Source
epmc
Published In
Conference Proceedings : ... Annual International Conference of the Ieee Engineering in Medicine and Biology Society. Ieee Engineering in Medicine and Biology Society. Annual Conference
Volume
6
Published Date
Start Page
4417
End Page
4420
DOI
10.1109/iembs.2004.1404228