title: New MRI markers for Alzheimer's disease: a meta-analysis of diffusion tensor imaging and a comparison with medial temporal lobe measurements.
abstract: The aim of the present study is to evaluate the diagnostic value of diffusion tensor imaging (DTI) for early Alzheimer's disease (AD) in comparison to widely accepted medial temporal lobe (MTL) atrophy measurements. A systematic literature research was performed into DTI and MTL atrophy in AD and mild cognitive impairment (MCI). We included seventy-six studies on MTL atrophy including 8,122 subjects and fifty-five DTI studies including 2,791 subjects. Outcome measure was the effect size (ES) expressed as Hedges g. In volumetric studies, atrophy of the MTL significantly differentiated between AD and controls (ES 1.32-1.98) and MCI and controls (ES 0.61-1.46). In DTI-Fractional anisotropy (FA) studies, the total cingulum differentiated best between AD and controls (ES = 1.73) and the parahippocampal cingulum between MCI and controls (ES = 0.97). In DTI-Mean diffusivity (MD) studies, the hippocampus differentiated best between AD and controls (ES = -1.17) and between MCI and controls (ES = -1.00). We can conclude that in general, the ES of volumetric MTL atrophy measurements was equal or larger than that of DTI measurements. However, for the comparison between controls and MCI-patients, ES of hippocampal MD was larger than ES of hippocampal volume. Furthermore, it seems that MD values have somewhat more discriminative power than FA values with higher ES in the frontal, parietal, occipital and temporal lobe.
authors.affiliation: Alzheimer Centre Limburg, School for Mental Health and Neuroscience (MHeNS), University Medical Centre, Maastricht, The Netherlands. l.clerx@maastrichtuniversity.nl
authors.forename: Lies
authors.initials: L
authors.lastname: Clerx
authors.forename: Pieter Jelle
authors.initials: PJ
authors.lastname: Visser
authors.forename: Frans
authors.initials: F
authors.lastname: Verhey
authors.forename: Pauline
authors.initials: P
authors.lastname: Aalten
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000544:Alzheimer Disease / Q000150:complications / Q000473:pathology; D001284:Atrophy; D060825:Cognitive Dysfunction / Q000209:etiology / Q000473:pathology; D056324:Diffusion Tensor Imaging / Q000379:methods; D007091:Image Processing, Computer-Assisted; D009483:Neuropsychological Tests; D039781:PubMed / Q000706:statistics & numerical data; D013702:Temporal Lobe / Q000473:pathology