Noninvasive perfusion MRI in Alzheimer's disease: a preliminary report.

We performed functional MRI using the echo-planar imaging and signal targeting with alternating radio frequency (EPISTAR) technique in 11 patients with Alzheimer's disease (AD) and 8 age-matched control subjects. Seven of the AD patients had qualitatively apparent focal areas of hypoperfusion in the posterior temporoparietal-occipital regions. At the earliest inversion time producing cortical enhancement, the ratios of parieto-occipital and temporo-occipital to whole slice signal intensity were significantly lower in the AD patients than in the controls. Parieto-occipital hypoperfusion correlated with dementia severity as measured by the Blessed Dementia Scale. EPISTAR may prove to be a rapid, noninvasive alternative to other functional neuroimaging modalities in the evaluation of patients with dementia.