Dynamic Total-Body PET/CT Acquisition and Reconstruction
All participants underwent dynamic [11C]CFT PET imaging using a total-body PET/CT scanner (uEXPLORER, United Imaging Healthcare). CT images were collected from vertex to toes for attenuation correction prior to PET acquisition. A 75-min PET scan was performed on each participant immediately after a lower limb intravenous bolus injection of 431.4±75.6 MBq 11C-CFT. The dynamic PET images were corrected for radioactive decay, scatter, attenuation, and random, and were reconstructed into a matrix with voxel size of 2.34 ×2.34×2.89 mm3 in x, y, z direction with ordered subset expectation maximization (OSEM) algorithm, time-of-flight (TOF) and point-spread function (PSF). The images were split into 97 frames (30×2 s, 12×5 s, 6×10 s, 4×30 s, 25×60 s, 15×120 s, 5×180 s)23, 24.