Imaging brain amyloid using the radioligand 18F-AV45 (Florbetapir F 18)

Abstract

We performed ¹⁸F-AV45 positron emission tomography (PET) on 17 patients with Alzheimer disease (AD), 6 patients with mild cognitive impairment (MCI), 6 patients with frontotemporal lobar degeneration (FTLD) and 5 healthy controls (HC). Dynamic PET was performed over approximately 90 min after tracer injection (370 MBq). Subsequently, we constructed time–activity curves. Standardized uptake values (SUVs) and cortex-to-cerebellum SUV ratios (SUVRs) were calculated with regions of interest at the cortical region (frontal, temporal, parietal, and occipital lobes) and other regions (putamen, thalamus, and pons) for all subjects. The SUVRs for patients with AD were greater than those for HC and the SUVRs for patients with MCI were intermediate. The SUVRs were higher for white matter than for gray matter in HC. However, the SUVRs were higher for gray matter than for white matter in patients with AD. The SUVRs in the frontal, parietal, and temporal regions were significantly higher for patients with AD than for HC or those with FTLD. The SUVRs in the frontal and parietal regions were significantly higher for patients with AD than those with MCI. The SUVRs in the occipital regions were not significantly different between patients with AD and other subjects. These results were consistent with those of previous reports on Aβ detection using ¹⁸F-AV45 PET and suggested that ¹⁸F-AV45 PET was probably effective in predicting the risk of onset of AD in patients with MCI, discriminating between AD dementia and non-AD dementia.