The clinical utility of visual evaluation of scintigraphic perfusion patterns for Alzheimer's disease using I-123 IMP SPECT

The authors examined the role of SPECT perfusion pattern in the diagnosis of Alzheimer's disease (AD) using I-123 IMP. They studied 93 patients who had memory and cognitive disorders, including 42 patients with a diagnosis of probable AD, classifying SPECT images into determined perfusion patterns. The probability of AD was 54% with bilateral temporal and/or parietal defects, 69% with bilateral temporoparietal defects with additional defects, 17% with no defects, end 11% with frontal defects only. The sensitivity of bilateral temporoparietal perfusion defects for AD was 95.2%, whereas the specificity was 56.9%. In the absence of bilateral temporal and/or parietal defects on visual evaluation of SPECT, the diagnosis of AD was unlikely, although it is not pathognomonic for AD, because this sign would he seen in various neuropsychiatric diseases causing memory end cognitive impairments. Visual evaluation of SPECT is of value in the diagnosis of AD among patients with dementia.