The Cingulate Island Sign on FDG‐PET Vs. IMP‐SPECT to Assess Mild Cognitive Impairment in Alzheimer's Disease Vs. Dementia with Lewy Bodies

The cingulate island sign (CIS) on 18F‐fluorodeoxyglucose positron emission tomography (FDG‐PET); ie, the relative preservation of mid‐posterior cingulate cortex metabolism, is a supportive biomarker in the diagnostic criteria for dementia with Lewy bodies (DLB). However, limited information is currently available on the diagnostic value of the CIS on FDG‐PET or 123I‐iodoamphetamine single‐photon emission computed tomography (IMP‐SPECT) for differentiating between mild cognitive impairment (MCI) due to Alzheimer's disease (AD) (MCI‐AD) and MCI due to DLB (MCI‐DLB).