Assessment of brain beta-amyloid deposition in transgenic mouse models of Alzheimer's disease with PET imaging agents 18 F-flutemetamol and 18 F-florbetaben.

BACKGROUND: Although amyloid beta (Aβ) imaging is widely used for diagnosing and monitoring Alzheimer's disease in clinical fields, paralleling comparison between 18 F-flutemetamol and 18 F-florbetaben was rarely attempted in AD mouse model. We performed a comparison of Aβ PET images between 18 F-flutemetamol and 18 F-florbetaben in a recently developed APPswe mouse model, C57BL/6-Tg (NSE-hAPPsw) Korl.

RESULTS: After an injection (0.23 mCi) of 18 F-flutemetamol and 18 F-florbetaben at a time interval of 2-3 days, we compared group difference of SUVR and kinetic parameters between the AD (n = 7) and control (n = 7) mice, as well as between 18 F-flutemetamol and 18 F-florbetaben image. In addition, bio-distribution and histopathology were conducted. With visual image and VOI-based SUVR analysis, the AD group presented more prominent uptake than did the control group in both the 18 F-florbetaben and 18 F-flutemetamol images. With kinetic analysis, the 18 F-florbetaben images showed differences in K1 and k4 between the AD and control groups, although 18 F-flutemetamol images did not show significant difference. 18 F-florbetaben images showed more prominent cortical uptake and matched well to the thioflavin S staining images than did the 18 F-flutemetamol image. In contrast, 18 F-flutemetamol images presented higher K1, k4, K1/k2 values than those of 18 F-florbetaben images. Also, 18 F-flutemetamol images presented prominent uptake in the bowel and bladder, consistent with higher bio-distribution in kidney, lung, blood and heart.

CONCLUSIONS: Compared with 18 F-flutemetamol images, 18 F-florbetaben images showed prominent visual uptake intensity, SUVR, and higher correlations with the pathology. In contrast, 18 F-flutemetamol was more actively metabolized than was 18 F-florbetaben (Son et al. in J Nucl Med 58(Suppl 1):S278, 2017].