Premium
P2‐243: Relationship between GM atrophy and WM disintegration in MRI of Alzheimer's disease patients
Author(s) -
Juh Rahyeong,
Kim Heeyoung,
Cho Un Jung,
Lee Jae Hong,
Kim Seong Yoon
Publication year - 2012
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2012.05.950
Subject(s) - uncinate fasciculus , cingulum (brain) , white matter , parahippocampal gyrus , atrophy , posterior cingulate , gyrus , voxel based morphometry , precuneus , fornix , temporal lobe , pathology , diffusion mri , superior frontal gyrus , medicine , neuroscience , psychology , fractional anisotropy , hippocampus , cortex (anatomy) , magnetic resonance imaging , cognition , radiology , epilepsy
change in MTL volume over time that maximizes measurement precision at the expense of anatomical accuracy. Methods: The Expectation Maximization (EM) segmentation is a model-based classification method used to define gray matter, white matter, and cerebrospinal fluid in baseline images. An atlas-based registration method was then used to define the MTL region of interest (ROI) on the gray matter pixels. A seeded region-growing algorithm was applied to the MTL ROI to smooth strongly-visible boundaries. Baseline images were registered to 24 months follow-up images using a deformable registration algorithm to propagate the MTL ROI defined on the baseline images and measure the change in volume. T1-weighted MP-RAGEMRI images acquired at baseline and at 24 months in 24 normal elderly subjects, 25 subjects with mild cognitive impairment (MCI) and 25 subjects with AD were randomly selected from the A lzheimer Disease Neuroimaging Initiative (ADNI) database to test the algorithm. The accuracy and precision were determined using 100 volumetric image sets of a cube phantom with known volume. Results: The known volume (mean 6 STD) of the cube phantom was underestimated by 3% 6 0.04%. The repeated measures ttest showed that there was a significant decrease (p <0.0001) in MTL volume in AD subjects. The MTL volume changes between baseline and 24 months (Mean6SEM, 75 6 46 mm 3 in the normal elderly, 456 38 mm 3 in subjects with MCI, and 2426 43 mm 3 in subjects with AD) were significantly different between groups (P<0.01). The Tukey post-hoc analysis showed a significant difference between AD and normal elderly (P <0.05); AD and MCI subjects (P <0.01). Conclusions: A fully automated segmentation method to measure MTL volume changes detected increased atrophy in the MTL in subjects with AD compared to MCI and control subjects.