Voxel-based analysis of multiple-system atrophy of cerebellar type: complementary results by combining voxel-based morphometry and voxel-based relaxometry.

Voxel-based relaxometry (VBR) is a novel morphometric method that analyses the relaxation rate R2 derived from multi-echo T2-weighted images on a voxel-by-voxel basis. We used VBR to study the brain morphology of 14 patients suffering from multiple-system atrophy of cerebellar type (MSA-C) and compared the results with those obtained by voxel-based morphometry (VBM) of T1-weighted images. VBR analysis revealed reduction of relaxation rate R2 in the cerebellum and brainstem reflecting infratentorial brain atrophy. The affected regions largely corresponded to those regions in which VBM showed reductions of grey and white matter. In addition, R2 was increased in the putamen, a region in which VBM did not show abnormalities. Our data show that the combination of VBR and VBM provided convergent and complimentary information about the brain morphology of MSA-C.