Young-Hoon Sung, Presenter: Nothing to Disclose

Namkug Kim PhD, Abstract Co-Author: Nothing to Disclose

In Kyoon Lyoo, Abstract Co-Author: Nothing to Disclose

Richard F Mollica, Abstract Co-Author: Nothing to Disclose

Perry F. Renshaw, Abstract Co-Author: Nothing to Disclose

To assess whole-brain metabolite changes related to traumatic brain injury in Vietnamese ex-political detainees using 3D magnetic resonance spectroscopic imaging (3D-MRSI).

Vietnamese ex-political detainees (n=16) and healthy controls (n=4) were scanned for the evaluation of the brain metabolite levels. All MR-related scan were performed using 3T Siemens scanner. 3D-MRSI Spectra were acquired using a multi-voxel PRESS technique (TR/TE=1500/30ms, FOV=200x200x120mm, matrix=16x16x8, BW=2000Hz, acquisition=512). Water suppression was achieved by applying CHESS saturation pulses. Parallel anatomical imaging was obtained using a T1-weighted, sagittal 3D-MPRAGE sequence (TR/TE/TI=2100/3.97/110 ms, matrix=256x256, FOV=256x256mm, flip angle=12degree, slice=1.5mm). 2D Double echo T2 weighted TSE sequence (TR=7110ms, TE=28/84ms, FOV=240x210, slice thickness=3mm, flip=150degree, bandwidth=179Hz/pixel) and axial FLAIR sequence (TR/TE/TI=8000/90/2500ms, slice thickness=5mm, FOV=240x168, bandwidth=200Hz/pixel) were used to screen for brain structural abnormalities. Spectra were analyzed using LCModel. Cramér-Rao lower bounds of 20% was set for the acceptable limit of the reliable detection of spectra. MRSI were co-registered with the corresponding anatomical images after tissue segmentation to estimate the metabolite levels of pure gray or white matter using a least-squares method.

In the whole-brain wise in-vivo metabolite analysis, Vietnamese ex-political detainees had significantly high level (18%) of white matter choline/Cr as compared to the healthy control subjects (p<0.006) without any significant structural abnormalities by MRI. Other metabolite ratios such as N-acetylaspartate (NAA/Cr), myo-inositol (mI/Cr) and glutamine+glutamate/Cr did not differ between the groups.

3D-MRSI could effectively evaluate the whole-brain metabolite abnormalities in the traumatic brains of Vietnamese torture survivors who exhibited no gross brain abnormalities. The increased choline levels in the Vietnamese ex-detainees suggests that glial rather than neuronal alterations may be a more sensitive marker for long lasting effects of the traumatic events persisting even decades after the torture.

This study provide a greater understanding of the long-term consequences of neurochemical changes in traumatic brains, and eventually will help for more accurate diagnosis and efficacy monitoring.

Sung, Y, Kim, N, Lyoo, I, Mollica, R, Renshaw, P, Brain Metabolite Abnormalities in Vietnamese Ex-Political Detainees Who Survived Traumatic Brain Injury and Torture.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8009246.html