Micro-PET/CT Imaging of 18F-GE180 and 18F-FDG in Rats

Micro-PET/CT imaging was conducted as described previously using a micro-PET/CT scanner (Siemens Inc., USA) [21 (link), 22 (link)]. Briefly, static PET/CT imaging was collected for 20 min at 40 min post intravenous injection [14 (link)] of ¹⁸F-GE180 (296–444 MBq/kg body weight) and at 50 min post intravenous injection of ¹⁸F-FDG (370–555 MBq/kg body weight). Then, the rats were positioned in a spread-supine position on the imaging bed and anesthetized by 2–3% isoflurane in medical oxygen (1–2 L/min) at room temperature with an isoflurane vaporizer (Molecular Imaging Products Company, USA) during the PET/CT procedure. PET/CT images were reconstructed using the ordered subsets expectation maximization 3D algorithm, and data were reviewed using Inveon Research Workplace software (Siemens). GE180 imaging was performed on the last day of the drug treatment phase (day 6, defined as the drug addiction group) and the response assessment phase (day 12), while FDG imaging was only performed on day 6 to assist in the establishment of the GE180 template. One animal died during the GE180 imaging on day 6, and one died during CPA training, so the final sample size of DA, DW and CPA groups was 11, 6 and 5, respectively.