TRADITIONAL POSTER - ismrm

2428. Comparison of Limbic Regions FA Using Tractography-Defined ROIs in AD and MCI
Darryl H. Hwang 1 , Sinchai Tsao 1 , Manbir Singh 1
1 Radiology and Biomedical Engineering, University of Southern California, Los Angeles, CA, United States
Poster Sessions
The limbic regions appear to be affected by mild cognitive impairment (MCI) and Alzheimer Disease (AD). We use normalized tractography to objectively
isolate the fornix and cingulum in a common template space for a voxel-based analysis of FA changes among normal control, MCI, and AD populations.
The results show FA change propagation from normals to MCI to AD with more changes in the right hemisphere, which is consistent with previous reports.
2429. Axial and Radial Diffusivity Measures Detect Brain Tissue Injury in Heart Failure Patients
Rajesh Kumar 1 , Mary A. Woo 2 , Paul M. Macey 2,3 , Gregg C. Fonarow 4 , Michele A. Hamilton 4 , Ronald M.
Harper 1,3
1 Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States; 2 School of Nursing, UCLA, Los
Angeles, CA, United States; 3 Brain Research Institute, UCLA, Los Angeles, CA, United States; 4 Cardiology, UCLA, Los Angeles,
CA, United States
Heart failure (HF) patients show injury in multiple brain sites, which may represent axonal or myelin injury, or both; however, the nature of the injury is
unclear. We assessed axial and radial diffusivity measures in HF, which show axonal and myelin changes, respectively. Axonal injury with reduced axonal
density or caliber appeared in internal capsule and cerebellar regions, and reduced myelin in temporal and frontal areas. Other brain sites, including internal
capsule and dorsomedial medulla showed myelin and axonal injury. The processes contributing to tissue injury in different brain regions are unknown, but
may include ischemic/hypoxic or inflammatory processes.
2430. Diffusion Two-Tensor Tractography Study on Inter-Hemispheric Connection Between Bilateral
Heschl’s Gyrus in Schizophrenia
Hsiao Piau Ng 1,2 , Marek Kubicki 1,3 , James Malcolm 1 , Yogesh Rathi 1,3 , Paula Pelavin 1 , Robert W.
McCarley 3 , Martha E. Shenton 1,3
1 Psychiatry Neuroimaging Lab, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; 2 Singapore
Bioimaging Consortium, Agency for Science, Technology and Research, Singapore, -, Singapore; 3 Clinical Neuroscience Division,
VA Boston Healthcare System, Harvard Medical School, Brockton, MA, United States
The connection between bilateral Heschl’s gyrus (HG) in normal controls (NC) and schizophrenics (SZ) is investigated using DTI here. Whole-brain
tractography was first generated using filtered two-tensor tractography method, instead of conventional streamline tractography. The relevant connection
was then extracted using the white matter of bilateral HGs as the ROIs. Measures for quantifying the connection are mean FA, mode, trace, parallel and
perpendicular diffusivity. Statistically significant between-group differences in trace, parallel and perpendicular diffusivity were observed. Our findings are
consistent with theories which suggest that SZ group has decreased WM pathology, particularly in regions associated with auditory and language processing.
2431. Connection Between Bilateral Superior Temporal Gyrus in Schizophrenia: A Preliminary Diffusion
Tensor Imaging Study
Hsiao Piau Ng 1,2 , Marek Kubicki 1,3 , Doug Terry 1 , Paula Pelavin 1 , Andrew Rausch 1 , Martha E. Shenton 1,3
1 Psychiatry Neuroimaging Lab, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; 2 Singapore
Bioimaging Consortium, Agency for Science, Technology and Research, Singapore, -, Singapore; 3 Clinical Neuroscience Division,
VA Boston Healthcare System, Harvard Medical School, Brockton, MA, United States
In this study, the connection between the bilateral STGs in normal controls (NC) and schizophrenics (SZ) is investigated using DTI measures, namely FA,
mode and trace. The connection was obtained from whole-brain streamline tractography using STGs white matter as ROIs. By dividing the connection into
three sub-regions (Left, Corpus Callosum and Right) and comparing the computed DTI measures of NC and SZ, we found statistically significant differences
in mean FA and mode in the Right region, with NC having greater values. This study paves the way for further localization of the differences in STGs
connection between NC and SZ.
2432. Compromised Frontal Callosal Connectivity in Unmedicated Obsessive-Compulsive Disorder: A
Quantitative Diffusion Tractography Study
Jungsu S. Oh 1,2 , Joon Hwan Jang 2 , Wi Hoon Jung 3 , Chi-Hoon Choi 4 , Jung-Seok Choi 5 , Do-Hyung Kang 5 ,
Jun Soo Kwon 2
1 Brain Korea 21 Division of Human Life Science, Seoul National University, Seoul, Korea, Republic of; 2 Psychiatry, Seoul National
University College of Medicine, Seoul, Korea, Republic of; 3 Interdisciplinary Program in Brain Science, Seoul National University,
Seoul, Korea, Republic of; 4 Radiology, National Medical Center, Seoul, Korea, Republic of; 5 Neuropsychiatry, Seoul National
University Hospital, Seoul, Korea, Republic of
Delineating frontostriatal network-related white matter tracts into dorsal/ventral pathways is of particular interest in obsessive-compulsive disorder (OCD)
studies. Hence we aim to investigate fractional anisotropy (FA) of dorsal/ventral projections of callosal fibers in OCD on the basis of quantitative diffusion
tractography analysis using Brodmann ROI approach and tract parameterization. We found significant FA decreases in callosal fibers of OCD in both
DLPFC/OFC projections, benefitting from function/region-specific tractography analysis. Thus we validated well-known abnormalities in these networks of
OCD. In particular, DLPFC-specific callosal fiber integrity was first revealed by the function/region-sensitivity of the present methods (not found by
previous methods).