Distinct perfusion patterns in Alzheimer's disease, frontotemporal dementia and dementia with Lewy bodies.

OBJECTIVES: To compare pseudo-continuous arterial spin-labelled (PCASL) magnetic resonance imaging (MRI) measured quantitative cerebral blood flow (CBF) of patients with frontotemporal dementia (FTD), dementia with Lewy Bodies (DLB), Alzheimer's disease (AD) and controls, in a region of interest (ROI) and voxel-wise fashion. METHODS: We analysed whole-brain 3D fast-spin-echo PCASL images of 20 FTD patients, 14 DLB patients, 48 AD patients and 50 controls from the Amsterdam Dementia Cohort. Regional CBF patterns were compared using analyses of variance for repeated measures. Permutation tests were used for voxel-wise comparisons. Analyses were performed using uncorrected and partial volume corrected (PVC) maps. All analyses were corrected for age and sex. RESULTS: There was an interaction between diagnosis and region (p < 0.001), implying differences in regional CBF changes between diagnostic groups. In AD patients, CBF was decreased in all supratentorial regions, most prominently so in the posterior regions. DLB patients showed lowest CBF values throughout the brain, but temporal CBF was preserved. Supratentorial PVC cortical CBF values were lowest in the frontal lobes in FTD patients, and in the temporal lobes in AD patients. CONCLUSIONS: Patients with AD, FTD and DLB display distinct patterns of quantitative regional CBF changes. 3D-PCASL may provide additional value in the workup of dementia patients. KEY POINTS: Patterns of regional CBF changes differ between AD, FTD and DLB patients. CBF is lower throughout the brain in DLB than AD and FTD. 3D-PCASL MRI is a potential non-invasive and easily accessible alternative to FDG-PET. 3D-PCASL MRI may be of additional value in the workup of dementia.