A 5-year longitudinal evaluation in patients with mild cognitive impairment by 11C-PIB PET/CT: a visual analysis

Objective The aim of this study was to evaluate the cerebral amyloid distribution in patients with mild cognitive impairment (MCI), assessed by carbon-11-Pittsburgh compound B (11C-PIB) PET/CT, after 5 years of follow-up. Patients and methods Ten amnestic MCI (A-MCI) and four nonamnestic (NA-MCI) patients were studied by 11C-PIB PET/CT and re-evaluated 5 years later by a new 11C-PIB PET/CT. PET/CT scans were acquired 60–90 min after the administration of 555 MBq 11C-PIB and analyzed visually, to obtain a score of the cerebral cortical 11C-PIB retention in the frontal, basal ganglia (BG), temporoparietal (TP), occipital, posterior cingulate, and cerebellum areas. Initial and 5-year follow-up 11C-PIB retentions were compared. Results Initially, 9/10 A-MCI patients were 11C-PIB positive and one was 11C-PIB negative. All four NA-MCI patients were 11C-PIB negative. Of the 11C-PIB-positive A-MCI patients, seven progressed to Alzheimer’s disease dementia (AD-D), one to mixed dementia and one remained as A-MCI. The 11C-PIB-negative A-MCI patient remained as A-MCI. Of the four 11C-PIB-negative NA-MCI, one progressed to semantic dementia. All changes in 11C-PIB retention were of low intensity. The A-MCI patients who progressed to AD-D (n=7) showed an increase in 11C-PIB retention in the frontal (5/7), BG (3/7), TP (3/7), occipital (1/7), and posterior cingulate (1/7) regions. The A-MCI patient who progressed to mix dementia showed an increase in 11C-PIB retention in the...
Source: Nuclear Medicine Communications - Category: Nuclear Medicine Tags: ORIGINAL ARTICLES Source Type: research