Intra- and interscanner variability of automated voxel-based volumetry based on a 3D probabilistic atlas of human cerebral structures

The intra- and inter-scanner variability of all automated method for MRI-based volumetry was investigated Using SPM5 algorithms and predefined masks derived from a probabilistic whole-brain atlas, this methods to determine the volumes of various brain structures (eg, hemispheres. lobes, cerebellum, basal allow ganglia. grey and white matter etc.) in single subjects in in observer-independent fashion. A healthy volunteer was scanned three times at six different MRI scanners (including different vendors and field strengths) to calculate intra- and inter-scanner volumetric coefficients of variation (CV). The mean intrascanner CV values per brain structure ranged from 0.50% to 4 4% (median, 0 89%). while the inter-scanner CV results varied between 0.66% and 14.7% (median, 4.74%) The overall (=combined intra- and inter-scanner) variability of measurements was only marginally higher, with CV results of 0.87-15.1% (median, 4 80%) Furthermore, the minimum percentage volume difference for detecting a significant volume change between two volume measurements in the same subject was calculated for each substructure For example, for the total brain volume, mean intra-scanner, inter-scanner. and overall CV results were 0.50%, 3.78%, and 3.80%, respectively, and the cut-offs for significant volume changes between two measurements in the same subject amounted to 1.4% for measurements on the same scanner and 10.5% oil different scanners. These findings may be useful for planning and assessing volumetric studies in neurological diseases, for the differentiation of certain patterns of atrophy, or for longitudinal studies monitoring the Course of a disease and potential therapeutic effects (C) 2009 Elsevier Inc. All rights reserved