%0 Journal Article
%T Applying surface-based hippocampal morphometry to study APOE-E4 allele dose effects in cognitively unimpaired subjects
%A Bolun Li
%A Boris A. Gutman
%A Emily H. Schron
%A Eric M. Reiman
%A Jianfeng Wu
%A Jie Shi
%A Kewei Chen
%A Leslie C. Baxter
%A Paul M. Thompson
%A Qunxi Dong
%A Richard J. Caselli
%A Travis McMahon
%A Wen Zhang
%A Yalin Wang
%J Archive of "NeuroImage : Clinical".
%D 2019
%R 10.1016/j.nicl.2019.101744
%X Apolipoprotein E (APOE) e4 is the major genetic risk factor for late-onset Alzheimer's disease (AD). The dose-dependent impact of this allele on hippocampal volumes has been documented, but its influence on general hippocampal morphology in cognitively unimpaired individuals is still elusive. Capitalizing on the study of a large number of cognitively unimpaired late middle aged and older adults with two, one and no APOE-e4 alleles, the current study aims to characterize the ability of our automated surface-based hippocampal morphometry algorithm to distinguish between these three levels of genetic risk for AD and demonstrate its superiority to a commonly used hippocampal volume measurement. We examined the APOE-e4 dose effect on cross-sectional hippocampal morphology analysis in a magnetic resonance imaging (MRI) database of 117 cognitively unimpaired subjects aged between 50 and 85£¿years (mean£¿=£¿57.4, SD£¿=£¿6.3), including 36 heterozygotes (e3/e4), 37 homozygotes (e4/e4) and 44 non-carriers (e3/e3). The proposed automated framework includes hippocampal surface segmentation and reconstruction, higher-order hippocampal surface correspondence computation, and hippocampal surface deformation analysis with multivariate statistics. In our experiments, the surface-based method identified APOE-e4 dose effects on the left hippocampal morphology. Compared to the widely-used hippocampal volume measure, our hippocampal morphometry statistics showed greater statistical power by distinguishing cognitively unimpaired subjects with two, one, and no APOE-e4 alleles. Our findings mirrored previous studies showing that APOE-e4 has a dose effect on the acceleration of brain structure deformities. The results indicated that the proposed surface-based hippocampal morphometry measure is a potential preclinical AD imaging biomarker for cognitively unimpaired individuals
%K APOE-e4
%K Hippocampal morphometry
%K Magnetic resonance imaging (MRI)
%K Alzheimer's disease
%K Cognitively unimpaired
%U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6411498/