Impact of Methodologic Choice for Automatic Detection of Different Aspects of Brain Atrophy by Using Temporal Lobe Epilepsy as a Model

C. Scanlon, S.G. Mueller, D. Tosun, I. Cheong, P. Garcia, J. Barakos, M.W. Weiner, K.D. Laxer
2011 American Journal of Neuroradiology  
BACKGROUND AND PURPOSE: VBM, DBM, and cortical thickness measurement techniques are commonly used automated methods to detect structural brain changes based on MR imaging. The goal of this study was to demonstrate the pathology detected by the 3 methods and to provide guidance as to which method to choose for specific research questions. This goal was accomplished by 1) identifying structural abnormalities associated with TLE with (TLE-mts) and without (TLE-no) hippocampal sclerosis, which are
more » ... nown to be associated with different types of brain atrophy, by using these 3 methods; and 2) determining the aspect of the disease pathology identified by each method. MATERIALS AND METHODS: T1-weighted MR images were acquired for 15 TLE-mts patients, 14 TLE-no patients, and 33 controls on a high-field 4T scanner. Optimized VBM was carried out by using SPM software, DBM was performed by using a fluid-flow registration algorithm, and cortical thickness was analyzed by using FS-CT. RESULTS: In TLE-mts, the most pronounced volume losses were identified in the ipsilateral hippocampus and mesial temporal region, bilateral thalamus, and cerebellum, by using SPM-VBM and DBM. In TLE-no, the most widespread changes were cortical and identified by using FS-CT, affecting the bilateral temporal lobes, insula, and frontal and occipital lobes. DBM revealed 2 clusters of reduced volume complementing FS-CT analysis. SPM-VBM did not show any significant volume losses in TLE-no. CONCLUSIONS: These results demonstrate that the 3 methods detect different aspects of brain atrophy and that the choice of the method should be guided by the suspected pathology of the disease. ABBREVIATIONS: DBM ϭ deformation-based morphometry; EMS ϭ expectation maximization segmentation; FDR ϭ false discovery rate; FS ϭ Freesurfer: FS-CT ϭ FS-based cortical thickness; FSL ϭ FMRIB Software Library; FWHM ϭ full width at half maximum; GM ϭ gray matter; ICV ϭ intracranial volume; SPM ϭ statistical parametric mapping; TLE ϭ temporal lobe epilepsy; TLEmts ϭ TLE-mesial temporal sclerosis; TLE-no ϭ TLE-normal-appearing hippocampus; ULD ϭ unbiased large deformation; VBM ϭ voxel-based morphometry; WM ϭ white matter
doi:10.3174/ajnr.a2578 pmid:21852375 pmcid:PMC3845529 fatcat:hst2ytoizvfjramkqdibj43ybe