Collaborative Computational Anatomy: An MRI Morphometry Study of the Human Brain Via Diffeomorphic Metric Mapping

This article describes a large multi-institutional analysis of the shape and structure of the human hippocampus in the aging brain as measured via MRI. The study was conducted on a popula- tion of 101 subjects including nondemented control subjects (n 5 57) and subjects clinically diagnosed with Alzheimer's Disease (AD, n 5 38) or semantic dementia (n 5 6) with imaging data collected at Washington University in St. Louis, hippocampal structure annotated at the Massachusetts General Hospital, and anatomical shapes embedded into a metric shape space using large deformation diffeo- morphic metric mapping (LDDMM) at the Johns Hopkins University. A global classifier was con- structed for discriminating cohorts of nondemented and demented subjects based on linear discrimi- nant analysis of dimensions derived from metric distances between anatomical shapes, demonstrating class conditional structure differences measured via LDDMM metric shape (P < 0.01). Localized analy- sis of the control and AD subjects only on the coordinates of the population template demonstrates shape changes in the subiculum and the CA1 subfield in AD (P < 0.05). Such large scale collaborative analysis of anatomical shapes has the potential to enhance the understanding of neurodevelopmental and neuropsychiatric disorders. Hum Brain Mapp 30:2132-2141, 2009. V 2008 Wiley-Liss, Inc.