title: Generalized tensor-based morphometry of HIV/AIDS using multivariate statistics on deformation tensors.
abstract: This paper investigates the performance of a new multivariate method for tensor-based morphometry (TBM). Statistics on Riemannian manifolds are developed that exploit the full information in deformation tensor fields. In TBM, multiple brain images are warped to a common neuroanatomical template via 3-D nonlinear registration; the resulting deformation fields are analyzed statistically to identify group differences in anatomy. Rather than study the Jacobian determinant (volume expansion factor) of these deformations, as is common, we retain the full deformation tensors and apply a manifold version of Hotelling's $T(2) test to them, in a Log-Euclidean domain. In 2-D and 3-D magnetic resonance imaging (MRI) data from 26 HIV/AIDS patients and 14 matched healthy subjects, we compared multivariate tensor analysis versus univariate tests of simpler tensor-derived indices: the Jacobian determinant, the trace, geodesic anisotropy, and eigenvalues of the deformation tensor, and the angle of rotation of its eigenvectors. We detected consistent, but more extensive patterns of structural abnormalities, with multivariate tests on the full tensor manifold. Their improved power was established by analyzing cumulative p-value plots using false discovery rate (FDR) methods, appropriately controlling for false positives. This increased detection sensitivity may empower drug trials and large-scale studies of disease that use tensor-based morphometry.
authors.affiliation: Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA. nlepore@loni.ucla.edu
authors.forename: N
authors.initials: N
authors.lastname: Lepore
authors.forename: C
authors.initials: C
authors.lastname: Brun
authors.forename: Y Y
authors.initials: YY
authors.lastname: Chou
authors.forename: M C
authors.initials: MC
authors.lastname: Chiang
authors.forename: R A
authors.initials: RA
authors.lastname: Dutton
authors.forename: K M
authors.initials: KM
authors.lastname: Hayashi
authors.forename: E
authors.initials: E
authors.lastname: Luders
authors.forename: O L
authors.initials: OL
authors.lastname: Lopez
authors.forename: H J
authors.initials: HJ
authors.lastname: Aizenstein
authors.forename: A W
authors.initials: AW
authors.lastname: Toga
authors.forename: J T
authors.initials: JT
authors.lastname: Becker
authors.forename: P M
authors.initials: PM
authors.lastname: Thompson
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000473:pathology; D000328:Adult; D000465:Algorithms; D001921:Brain / Q000473:pathology*; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D018792:Encephalitis, Viral / Q000473:pathology*; D005260:Female; D015658:HIV Infections / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D016247:Information Storage and Retrieval / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008959:Models, Neurological; D015233:Models, Statistical; D015999:Multivariate Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity