title: Longitudinal and cross-sectional analysis of atrophy in Alzheimer's disease: cross-validation of BSI, SIENA and SIENAX.
abstract: Brain volume loss (atrophy) is widely used as a marker of disease progression. Atrophy has been measured with a variety of methods, some estimating atrophy rate from two temporally separated scans, and others estimating atrophy state from a single scan. Three popular tools for measuring brain atrophy are BSI and SIENA (rate) and SIENAX (state). Previous papers have shown BSI and SIENA to have similar accuracy, but no work has carefully compared both methods using the same data set. Here we compare these methods, using data from patients with Alzheimer's disease and age-matched controls. We also compare the SIENA longitudinal measure with atrophy state estimated by SIENAX using just the earliest scan taken from each subject. We show strong correspondence and similar sensitivity to atrophy between all 3 measures.
authors.affiliation: Oxford University Centre for Functional MRI of the Brain (FMRIB), Oxford, UK. steve@fmrib.ox.ac.uk
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Smith
authors.forename: Anil
authors.initials: A
authors.lastname: Rao
authors.forename: Nicola
authors.initials: N
authors.lastname: De Stefano
authors.forename: Mark
authors.initials: M
authors.lastname: Jenkinson
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Schott
authors.forename: Paul M
authors.initials: PM
authors.lastname: Matthews
authors.forename: Nick C
authors.initials: NC
authors.lastname: Fox
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis*; D016477:Artifacts; D001185:Artificial Intelligence; D001284:Atrophy; D001921:Brain / Q000473:pathology*; D002552:Cerebral Ventricles / Q000473:pathology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012016:Reference Values; D012680:Sensitivity and Specificity; D012984:Software