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:

Motion-immune neuro and body MRI for challenging patient populations

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

Network Plasticity in Pediatric Traumatic Brain Injury

Administered By
Pediatrics, Neurology
Role
Mentor
Start Date
End Date

Multidisciplinary Neonatal Training Grant

Administered By
Pediatrics, Neonatology
Awarded By
National Institutes of Health
Role
Mentor
Start Date
End Date

Oncogenic Signaling Networks

Administered By
Surgery, Surgical Sciences
Awarded By
Department of Defense
Role
Co Investigator
Start Date
End Date

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

Publications:

Integrated parallel reception, excitation, and shimming (iPRES) with multiple shim loops per radio-frequency coil element for improved B0 shimming.

PURPOSE: Integrated parallel reception, excitation, and shimming (iPRES) coil arrays allow radio-frequency currents and direct currents to flow in the same coils, which enables excitation/reception and localized B0 shimming with a single coil array. The purpose of this work was to improve their shimming performance by adding the capability to shim higher-order local B0 inhomogeneities that are smaller than the radio-frequency coil elements. METHODS: A novel design was proposed in which each radio-frequency/shim coil element is divided into multiple direct current loops, each using an independent direct current current, to increase the number of magnetic fields available for shimming while maintaining the signal-to-noise ratio of the coil. This new design is termed iPRES(N), where N represents the number of direct current loops per radio-frequency coil element. Proof-of-concept phantom and human experiments were performed with an 8-channel body coil array to demonstrate its advantages over the original iPRES(1) design. RESULTS: The average B0 homogeneity in various organs before shimming and after shimming with the iPRES(1) or iPRES(3) coil arrays was 0.24, 0.11, and 0.05 ppm, respectively. iPRES(3) thus reduced the B0 inhomogeneity by 53% and further reduced distortions in echo-planar images of the abdomen when compared with iPRES(1). CONCLUSION: iPRES(N) can correct for localized B0 inhomogeneities more effectively than iPRES(1) with no signal-to-noise ratio loss, resulting in a significant improvement in image quality. Magn Reson Med 77:2077-2086, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Authors
Darnell, D; Truong, T-K; Song, AW
MLA Citation
Darnell, Dean, et al. “Integrated parallel reception, excitation, and shimming (iPRES) with multiple shim loops per radio-frequency coil element for improved B0 shimming..” Magn Reson Med, vol. 77, no. 5, May 2017, pp. 2077–86. Pubmed, doi:10.1002/mrm.26267.
URI
https://scholars.duke.edu/individual/pub1132271
PMID
27174387
Source
pubmed
Published In
Magn Reson Med
Volume
77
Published Date
Start Page
2077
End Page
2086
DOI
10.1002/mrm.26267

Regionally selective atrophy of subcortical structures in prodromal HD as revealed by statistical shape analysis.

Huntington disease (HD) is a neurodegenerative disorder that involves preferential atrophy in the striatal complex and related subcortical nuclei. In this article, which is based on a dataset extracted from the PREDICT-HD study, we use statistical shape analysis with deformation markers obtained through "Large Deformation Diffeomorphic Metric Mapping" of cortical surfaces to highlight specific atrophy patterns in the caudate, putamen, and globus pallidus, at different prodromal stages of the disease. On the basis of the relation to cortico-basal ganglia circuitry, we propose that statistical shape analysis, along with other structural and functional imaging studies, may help expand our understanding of the brain circuitry affected and other aspects of the neurobiology of HD, and also guide the most effective strategies for intervention.
Authors
Younes, L; Ratnanather, JT; Brown, T; Aylward, E; Nopoulos, P; Johnson, H; Magnotta, VA; Paulsen, JS; Margolis, RL; Albin, RL; Miller, MI; Ross, CA; PREDICT-HD Investigators and Coordinators of the Huntington Study Group,
MLA Citation
Younes, Laurent, et al. “Regionally selective atrophy of subcortical structures in prodromal HD as revealed by statistical shape analysis..” Hum Brain Mapp, vol. 35, no. 3, Mar. 2014, pp. 792–809. Pubmed, doi:10.1002/hbm.22214.
URI
https://scholars.duke.edu/individual/pub1019711
PMID
23281100
Source
pubmed
Published In
Hum Brain Mapp
Volume
35
Published Date
Start Page
792
End Page
809
DOI
10.1002/hbm.22214

Myelin water weighted diffusion tensor imaging.

In this study we describe our development and implementation of a magnetization transfer (MT) prepared stimulated-echo diffusion tensor imaging (DTI) technique that can be made sensitive to the microanatomy of myelin tissue. The short echo time (TE) enabled by the stimulated-echo acquisition preserves significant signal from the short T(2) component (myelin water), and the MT preparation further provides differentiating sensitization to this signal. It was found that this combined strategy could provide sufficient sensitivity in our first attempt to image myelin microstructure. Compared to the diffusion tensor derived from the conventional DTI technique, the myelin water weighted (MWW) tensor has the same principal diffusion direction but exhibits a significant increase in fractional anisotropy (FA), which is mainly due to a decrease in radial diffusivity. These findings are consistent with the microstructural organization of the myelin sheaths that wrap around the axons in the white matter and therefore hinder radial diffusion. Given that many white matter diseases (e.g. multiple sclerosis) begin with a degradation of myelin microanatomy but not a loss of myelin content (e.g. loosening of the myelin sheaths), our newly implemented MWW DTI has the potential to lead to improved assessment of myelin pathology and early detection of demyelination.
Authors
Avram, AV; Guidon, A; Song, AW
MLA Citation
Avram, Alexandru V., et al. “Myelin water weighted diffusion tensor imaging..” Neuroimage, vol. 53, no. 1, Oct. 2010, pp. 132–38. Epmc, doi:10.1016/j.neuroimage.2010.06.019.
URI
https://scholars.duke.edu/individual/pub799552
PMID
20587369
Source
epmc
Published In
Neuroimage
Volume
53
Published Date
Start Page
132
End Page
138
DOI
10.1016/j.neuroimage.2010.06.019

Diffusion tensor imaging fiber tracking with local tissue property sensitivity: phantom and in vivo validation.

Diffusion tensor imaging (DTI) provides directional information that can be used to delineate brain white matter connections noninvasively via fiber tracking. The most commonly used methods for tractography are based on the streamline tracking algorithm for track propagation and a set of empirically and globally defined criteria for track termination. In this study, we propose a streamline tracking algorithm with high-order propagation accuracy and a single termination criterion based on tissue property to minimize user intervention and biases introduced during tracking process. These advantages and the agreement with histological reports are demonstrated in our tracking results in phantoms and in humans.
Authors
Chen, B; Song, AW
MLA Citation
Chen, Bin, and Allen W. Song. “Diffusion tensor imaging fiber tracking with local tissue property sensitivity: phantom and in vivo validation..” Magn Reson Imaging, vol. 26, no. 1, Jan. 2008, pp. 103–08. Pubmed, doi:10.1016/j.mri.2007.05.003.
URI
https://scholars.duke.edu/individual/pub799558
PMID
17587528
Source
pubmed
Published In
Magnetic Resonance Imaging
Volume
26
Published Date
Start Page
103
End Page
108
DOI
10.1016/j.mri.2007.05.003

Hemodynamic correlates of stimulus repetition in the visual and auditory cortices: an fMRI study.

We examined the effects of stimulus repetition upon the evoked hemodynamic response (HDR) in auditory and visual cortices measured by magnetic resonance imaging in two experiments. Experiment 1 focused on the effects of the interval duration between two identical stimuli on HDR. Pure auditory tones (1000 Hz) of 100-ms duration were presented singly or in pairs with intrapair intervals (IPIs: onset-to-onset) of 1, 4, and 6 s. In Experiment 2, using a within-subject design, we aimed to compare the HDR refractory period in both sensory cortices as well as the HDRs to auditory and visual stimuli. Identical auditory tone as described above and visual stimuli of 500-ms high-contrast checkerboard patterns were presented singly or in identical pairs with an IPI of 1 s. Images were acquired at 1.5 T using a gradient-echo echo-planar imaging sequence sensitive to blood oxygenation level-dependent (BOLD) contrast. Experiment 1 revealed that the HDR evoked by an auditory stimulus is followed by a refractory period of 4-6 s in the auditory cortex, as indicated by smaller HDR amplitudes to the second of each pair of stimuli. Furthermore, peak latency was dependent upon IPI, with longer latencies observed for shorter IPIs. Experiment 2 revealed that the HDR evoked in both sensory cortices by paired stimulus presentations is suppressed and delayed similarly by the refractory effects imposed by the preceding stimulus, suggesting similar refractory properties of the HDR at this specific IPI. We also provide evidence for additional neural resource allocation in response to repeated stimuli.
Authors
Inan, S; Mitchell, T; Song, A; Bizzell, J; Belger, A
MLA Citation
Inan, Seniha, et al. “Hemodynamic correlates of stimulus repetition in the visual and auditory cortices: an fMRI study..” Neuroimage, vol. 21, no. 3, Mar. 2004, pp. 886–93. Epmc, doi:10.1016/j.neuroimage.2003.10.029.
URI
https://scholars.duke.edu/individual/pub799561
PMID
15006655
Source
epmc
Published In
Neuroimage
Volume
21
Published Date
Start Page
886
End Page
893
DOI
10.1016/j.neuroimage.2003.10.029