Diagnosis of dementia using perfusion SPECT imaging at the patient's initial visit to a cognitive disorder clinic

PURPOSE: This study was performed to evaluate the diagnostic accuracy of brain perfusion SPECT in patients visiting the cognitive disorder clinic for initial evaluation using 3D-SSP compared with using standard transaxial section. MATERIALS AND METHODS: Standard transaxial section displays and 3D-SSP z-score maps obtained after administration of Tc-99m ECD or I-123 IMP were randomly interpreted in 315 patients who visited initially to the cognitive disorder clinic (age 46-88 years; 162 women, 153 men). Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were calculated and receiver operating characteristic (ROC) analysis was performed. RESULTS: One hundred thirty-seven patients were clinically diagnosed with Alzheimer disease and 178 patients were diagnosed with other disorders and age-associated cognitive decline. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy calculated using standard transaxial display were 61%, 70%, 61%, 70%, and 66%, respectively, and using the 3D-SSP z-score map were 90%, 74%, 73%, 90%, and 81%, respectively. Particularly, the sensitivity value improved in mild cases compared with severe cases using 3D-SSP. Diagnostic performance with 3D-SSP was superior in both mild dementia (Az = 0.64 [section] vs 0.81 [3D-SSP], P = 0.001) and severe dementia (Az = 0.75 [section] vs 0.90 [3D-SSP], P = 0.002). CONCLUSIONS: Brain perfusion SPECT was useful for diagnosis in patients who come to the cognitive disorder clinic for initial evaluation using 3D-SSP.