Dual-phase 18F-florbetaben PET provides cerebral perfusion proxy along with beta-amyloid burden in Alzheimer’s disease
Hai-Jeon Yoon, Bom Sahn Kim, Jee Hyang Jeong, Geon Ha Kim, Hee Kyung Park, Min Young Chun, Seunggyun Ha
Abstract
This study investigated changes in brain perfusion and Aβ burden according to the progression of Alzheimer’s disease (AD) by using a dual-phase 18F-florbetaben (FBB) PET protocol. Sixty subjects, including 12 with Aβ-negative normal cognition (Aβ−NC), 32 with Aβ-positive mild cognitive impairment (Aβ+MCI), and 16 with Aβ-positive AD (Aβ+AD), were enrolled. A dynamic PET scan was obtained in the early phase (0–10 min, eFBB) and delayed phase (90–110 min, dFBB), which were then averaged into a single frame, respectively. In addition to the averaged eFBB, an R1 parametric map was calculated from the eFBB scan based on a simplified reference tissue model (SRTM). Between-group regional and voxel-wise analyses of the images were performed. The associations between cognitive profiles and PET-derived parameters were investigated. Both the R1 and eFBB perfusion reductions in the cortical regions were not significantly different between the Aβ−NC and Aβ+MCI groups, while they were significantly reduced from the Aβ+MCI to Aβ+AD groups in regional and voxel-wise analyses. However, cortical Aβ depositions on dFBB were not significantly different between the Aβ+MCI and Aβ+AD groups. There were strong positive correlations between the R1 and eFBB images in regional and voxel-wise analyses. Both perfusion components showed significant correlations with general and specific cognitive profiles. The results of this study demonstrated the feasibility of dual-phase 18F-FBB PET to evaluate different trajectories of dual biomarkers for neurodegeneration and Aβ burden over the course of AD. In addition, both eFBB and SRTM-based R1 can provide robust indices of brain perfusion.