Poster E97, Monday, March 27, 2:30 – 4:30 pm, Pacific Concourse
Quantification for spatial variability of white matter hyperintensities
Jin-Ju Yang1, Jong-Min Lee*1, Hee Jin Kim2, Sang Won Seo2; 1Hanyang University, Seoul, Korea, 2Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
White matter hyperintensities (WMH) are typically detected on fluid-attenuated inversion recovery (FLAIR) or T2 weighted images and are commonly observed in older adults. Although volume of WMH has been used widely in many previous studies to identify white matter damage, little is known about the impact of spatial variability of WMH. In this study, we assessed for the first time to quantify the spatial distribution of WMH using information theory. WMH volume was segmented on FLAIR image and white matter brain was parcellated into 58 regions of interest (ROIs) with lobes and deep white matter tract labels. We calculated entropy of information using the probability that voxel of WMH is in the ROIs. We thoroughly selected 153 of normal cognitive elder (NC) and 201 subjective mild impairment (SMI) having a WMH. Histogram of WMH entropy (NC, 3.58, 0.31 (mean, standard deviation); SMI, 4.23, 0.28) was showed more separable between NC and SMI group comparing to those of WMH volume (NC, 11547.82, 5621.93; SMI, 18865.95, 11263.69). Although group difference was statistically observed both WMH volume (F=54.27; P<0.0001) and WMH entropy (F=432.97; P<0.0001), the age interaction effect for group difference was only detected in WMH entropy (F=4.98; P =0.026). These findings provide direct evidence for better understanding how variability of white matter injury differs in NC and SMI, since WMH are pathologically heterogeneous, ranging from subtle alterations to severe axonal and myelin loss and may be related to one of a variety of different region-specific neuroanatomical mechanisms.
Topic Area: METHODS: Neuroimaging