A voxel-based morphometry comparison of the 3.0T ADNI-1 and ADNI-2 volumetric MRI protocols

OBJECTIVES: The Alzheimer's Disease Neuroimaging Initiative 3.0T MRI image acquisition scheme changed between the original ADNI-1 grant and the two subsequent grants (ADNI-GO and ADNI-2). The aim of the current study was to investigate the compatibility of the 3.0T ADNI-1 and ADNI-2 T1-weighted volumes using voxel-based morphometry (VBM). METHODS: T1-weighted images of 30 subjects were acquired using a 3T GE Signa HDx using the ADNI-1 and ADNI-2 T1-weighted volume sequences. Images were pre-processed and analysed using SPM8. Global grey matter (GM), white matter (WM) and cerebrospinal fluid (CSF) volumes were compared, as well as voxel-by-voxel differences in GM and WM. RESULTS: Correlation coefficients and percentage differences for each tissue type between ADNI-1 and ADNI-2 were as follows: ((GM: intraclass correlation coefficient (ICC) = 0.86, ADNI-1 3.09% < ADNI-2) (WM: ICC = 0.91, ADNI-1 2.92% > ADNI-2) (CSF: ICC = 0.90, ADNI-1 1.94% > ADNI-2)). For ADNI-2, widespread increases in GM were found relative to ADNI-1 (cerebellum and pre-central gyrus), with localised decreases along the midline and temporal lobes. For ADNI-1, widespread increases in WM were found relative to ADNI-2 (cerebellum and pre-central gyrus), together with localised decreases in the temporal gyrus. CONCLUSIONS: The widespread increase in GM and localised decrease in WM in ADNI-2 compared to ADNI-1 images suggests that the image acquisition protocols are not directly comparable using SPM-8. Total volumes of GM, WM and CSF also differed between the protocols in the following order of magnitude: GM > WM > CSF. This has implications for studies aiming to analyse images acquired using the ADNI-1 and ADNI-2 protocols under VBM. © 2014 The Authors. International Journal of Geriatric Psychiatry published by John Wiley & Sons Ltd.