18FDG PET-CT is useful for early and differential diagnosis of dementia. ASL-MRI seems an attractive alternative. Visual agreement was calculated in 21 brain regions bilaterally in 9/11 patients with suspected early-stage dementia, excluding 2 patients due to ASL-MRI motion artefacts. Overall gross agreement was almost perfect and identical between and within modalities (κ=0.85-0.86, p<0.05). Intermodality regional agreement was variable, moderate (κ=0,56 in posterior cingulate) to perfect (including in precuneus), not different from intramodality agreement. Diagnostic accuracy was 5/9 (56%) for ASL-MRI and 7/9 (78%) for FDG PETCT. (p=0.31). Clinical experience and optimisation may further improve ASL-MRI's performance.