[C-11]BF-227 PET imaging of amyloid deposition in AD, MCI, and normal subjects

Objectives [C-11] BF-227 (2-(2-[2-dimethylaminothiazol-5-yl]ethenyl)- 6-(2-[fluoro]ethoxy) benzoxazole) is a PET probe for detection of dense amyloid deposits, which has been developed in Tohoku University. The purpose of this study was to evaluate BF-227 binding in normal subjects, patients with Alzheimer’s disease (AD) and mild cognitive impairment (MCI).

Methods The subjects were seven patients with AD (mean age 73+/-11 years old), eight patients with MCI (age 69+/-10 y.o.), and 15 healthy normal volunteers (NCn15, age 68+/-4 y.o.). They underwent Brain [C-11]BF-227 PET, 3D-MR imaging, and neuropsychological tests. BF-227 dynamic PET was performed for 60 min after the injection of 370-740 MBq [C-11] BF-227. Spatially normalized SUVR images were calculated from static 20-40 min images using the reference values in the cerebellar region of interest (ROI). Fifteen normal subjects were divided into 11 subjects with low SUVR (NCn11, age 69+/-5 y.o.) and four subjects with high SUVR by leave-one-out cross-validation. Statistical comparisons and correlation analyses were performed on voxel-by-voxel (SPM) and ROI basis.

Results AD showed higher accumulation of BF-227 in the parieto-temporal, medial frontal, precuneus, and posterior cingulate areas than NCn11 (p<0.05, ext>200). MCI showed intermediate binding between AD and NCn11 in voxel-based and ROI analyses. The SUVR ROI value was inversely correlated with MMSE (p<0.05) and WMS-R logical memory II (p<0.05).

Conclusions The results suggest that BF-227 binding corresponds to pathological and symptomatic progression from normal to AD.