title: Diagnostic utility of hippocampal size and mean diffusivity in amnestic MCI.
abstract: Hippocampus atrophy is a frequent finding in mild cognitive impairment (MCI), whereas diffusion-tensor-imaging (DTI) has demonstrated its value to detect subtle brain tissue changes in several neuropsychiatric diseases including MCI. To compare the diagnostic accuracy of both methods, high resolution MRI scans for hippocampus volumetry, and co-registered DTI-scans for ROI-based mean diffusivity (MD) and fractional anisotropy (FA) were carried out in 18 patients with amnestic MCI (7 females, age 67.3+/-8.7 years, MMSE 25.2+/-2.2) and 18 controls (age 66.9+/-9.0 years, MMSE 28.7+/-1.0). Diagnostic properties of normalized hippocampus volume (HV) and DTI measures with regard to MCI status were estimated by receiver operating characteristics (ROC) analyses and logistic regression. Parameters of the left hippocampus showed superior predictive power when compared to the right. At a specificity set to 80%, left HV had low sensitivity (50%); left hippocampal MD values revealed superior sensitivity (89%), similar to left hippocampal FA (78%). The results demonstrate higher sensitivity of DTI-derived left hippocampal parameters than volume measures in detecting subtle hippocampal abnormalities related to MCI.
authors.affiliation: Department of Psychiatry, University of Mainz, Untere Zahlbacher Str. 8, D-55131 Mainz, Germany. mjmueller@gmx.de <mjmueller@gmx.de>
authors.forename: Matthias J
authors.initials: MJ
authors.lastname: Müller
authors.forename: Dirk
authors.initials: D
authors.lastname: Greverus
authors.forename: Carsten
authors.initials: C
authors.lastname: Weibrich
authors.forename: Paulo Roberto
authors.initials: PR
authors.lastname: Dellani
authors.forename: Armin
authors.initials: A
authors.lastname: Scheurich
authors.forename: Peter
authors.initials: P
authors.lastname: Stoeter
authors.forename: Andreas
authors.initials: A
authors.lastname: Fellgiebel
mesh_terms: D000368:Aged; D000647:Amnesia / Q000175:diagnosis* / Q000503:physiopathology*; D000704:Analysis of Variance; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000175:diagnosis* / Q000503:physiopathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D007839:Functional Laterality; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D015203:Reproducibility of Results