Vertex-Wise Shape Analysis of the Hippocampus: Disentangling Positional Differences from Volume Changes [chapter]

Hosung Kim, Tommaso Mansi, Andrea Bernasconi, Neda Bernasconi
2011 Lecture Notes in Computer Science  
Hippocampal atrophy and developmental positional variants may cooccur in various neurological disorders. We propose a surface-based framework to analyze independently volume and positioning. After extracting the spherical harmonics combined with point distribution models (SPHARM-PDM) from manual labels, we computed displacement vectors between individual surfaces and the template. Then, we computed surface-based Jacobian determinants (SJD) from these vectors to localize volume changes. To
more » ... e positional variants, we constructed a mean meridian axis (MEMAX), inheriting the shape-constrained point correspondences of SPHARM, on which we compute local curvatures and position vectors. We validated our method on synthetic shapes, and a large database of healthy subjects and patients with temporal lobe epilepsy. Our comprehensive analysis showed that in patients atrophy and positional changes cooccurred at the level of the posterior hippocampus. Indeed, in this region, while SPHARM-PDM showed mirrored deformations, SJD detected atrophy, and shape analysis of MEMAX unveiled medial positioning due to bending.
doi:10.1007/978-3-642-23629-7_43 fatcat:jfx3xjvwobcbpdv4vs2fym4owy