Diagnostic accuracy of single photon emission computed tomography in Alzheimer's disease.

To determine whether the detection of parietotemporal functional abnormalities as demonstrated by single photon emission computed tomography (SPECT) can be employed as a diagnostic marker for Alzheimer's disease (AD), we studied 219 patients with neurologic disorders including 56 with AD and 25 healthy controls. The diagnostic sensitivity (parietotemporal hypoperfusion present in AD patients) was 82%, and the specificity (parietotemporal hypoperfusion absent in non-AD patients and controls) was 89%. These results suggest that SPECT imaging provides an accurate and sensitive diagnostic test for AD.