Pittsburgh Compound B (11C-PIB) and Fluorodeoxyglucose (18 F-FDG) PET in Patients With Alzheimer Disease, Mild Cognitive Impairment, and Healthy Controls

Amyloid load in the brain using Pittsburgh compound B ( 11 C-PIB) positron emission tomography (PET) and cerebral glucose metabolism using fluorodeoxyglucose ( 18 F-FDG) PET were evaluated in patients with mild Alzheimer disease (AD, n ¼ 18), mild cognitive impairment (MCI, n ¼ 24), and controls (CTR, n ¼ 18). 11 C-PIB binding potential (BPND) was higher in prefrontal cortex, cingulate, parietal cortex, and precuneus in AD compared to CTR or MCI and in prefrontal cortex for MCI compared to CTR. For 18 F-FDG, regional cerebral metabolic rate for glucose (rCMRGlu) was decreased in precuneus and parietal cortex in AD compared to CTR and MCI, with no MCI–CTR differences. For the AD–CTR comparison, precuneus BPND area under the receiver operating characteristic (ROC) curve (AUC) was 0.938 and parietal cortex rCMRGlu AUC was 0.915; for the combination, AUC was 0.989. 11 C-PIB PET BPND clearly distinguished diagnostic groups and combined with 18 F-FDG PET rCMRGlu, this effect was stronger. These PET techniques provide complementary information in strongly distinguishing diagnostic groups in crosssectional comparisons that need testing in longitudinal studies.