Umi510

This retrospective analysis was performed on patients who underwent ⁶⁸Ga-FAPI-04 PET/CT (Biograph mCT, Siemens Healthineers, Germany; Ingenuity TF, Philips Healthcare, USA; uMI510, United Imaging, China) or ⁶⁸Ga-FAPI-04 PET/MR (uPMR790 TOF, United Imaging, China) from April 2020 to August 2021. The inclusion criteria were as follows: (i) patients who were able to sign informed consents for examination according to the guidelines of the Clinical Research Ethics Committee; (ii) patients with a predicted survival of more than 6 months. Exclusion criteria were (i) pregnancy, (ii) postmenopausal women with taking hormone replacement or related drugs, and (iii) patients with a predicted survival of <6 months.

All patients were scanned using an integrated whole-body PET/CT scanner (uMI510, United Imaging Healthcare, Shanghai, China; or Discovery 710, GE Healthcare, Chicago, IL, USA) and had fasted for at least 6 h before the scan with plasma glucose levels <11.1 mmol/L and rested for at least 30 min in a quiet waiting room before ¹⁸F-FDG administration. The acquisition time was 150 s per bed position. Low-dose CT (110 kV, 25–50 mAs) was chosen for anatomic localization and attenuation correction. Images were reconstructed using a standard ordered-subset expectation-maximization algorithm. The patients were intravenously injected with ¹⁸F-FDG (Atomic High-Tech Co., Changzhou, China; radiochemical purity >95%); the radioactive dose was calculated according to body weight, with a dose range of 3.70–4.44 MBq/kg (0.01–0.12 mCi/kg). The PET/CT scan was performed 1 h after injection.
All PET images were transformed into SUV units by normalizing the activity concentration to the administered ¹⁸F-FDG dose and the patient’s body weight after decay correction. The images were reconstructed with CT attenuation correction using the ordered subset expectation maximization algorithm. All CT images were converted to a bone window.