Biograph mct flow 64 scanner

PET/CT imaging was performed using a Biograph mCT Flow 64 scanner from Siemens Healthcare AG. Whole-body PET/CT scans were acquired in the supine position from vertex to feet at various time intervals. PET scans were obtained using the continuous bed motion mode with a speed of 1.5 mm/s for the acquisitions 50 min and 2 h p.i. The 18.5 h and 25 h scans were acquired using a scan speed of 1.1 mm/s. Reconstructions were performed using recon TrueX+ToF with 3 iterations and 21 subsets and images were prepared using a Gaussian filter (2 mm FWHM) and a matrix size of 200. CT scans were acquired at 100 kV and at pitch of 1.5. CareDose4D was applied using a 0.5-s gantry rotation time, 5-mm slice thickness, and a matrix size of 512 × 512.

All patients were fasting for more than 4 h before examination, and the plasma glucose levels were lower than 10 mmol/L. Then, patients were injected with 3.0–3.7 MBq/kg ¹⁸F-FDG. After rest for about 1 h, the whole-body PET/CT scan was acquired using a Biograph mCT Flow 64 scanner (Siemens, Erlangen, Germany) (120 kV; 310 mAs; slice, 3 mm; matrix, 200 × 200; filter, 5-mm Gaussian), continuous table moving acquisition with a flow speed of 1.5 mm/s over the torso of each subject (from the base of the skull to the middle of the femur). The reconstruction algorithm is ordered subset expectation maximum, iteration 2, subset 21, with point spread function (PSF) and time of flight (TOF) enabled.

No specific preparation was required for the subjects on the day of ⁶⁸Ga‐HZ20 PET scanning. A low‐dose CT scan (120 kV, 35 mA, slice 0.6 mm, matrix 512 × 512) was per‐formed before the ⁶⁸Ga‐HZ20 injection. Then, a whole‐body dynamic PET scan was performed immediately after the intra‐venous injection of ⁶⁸Ga‐HZ20 in all subjects and continued for ≈40 min (five passes, round 10 min for each pass). All the subjects also underwent static whole‐body PET/CT scan at 90 and 180 min post‐injection. Dynamic whole‐body PET/CT scans were performed on a Biograph mCT Flow 64 scanner (Siemens, Erlangen, Germany) with the setting of 120 kV, 146 mAs, slice 3 mm, matrix 200 × 200, full width at half maximum (FWHM) 5 mm, filter: Gaussian, field of view (FOV) 256 (head), 576 (body). The patient bed was set to continuously move at a speed of 2 mm s⁻¹ to cover the entire body of each subject (from the top of the skull to the middle of the femur). Static whole‐body PET/CT scan used a speed of 1 mm s⁻¹ at 90 min and 0.8 mm s⁻¹ at 180 min. 3D iterative reconstruction was applied for image reconstruction, with CT‐based attenuation and scatter correction through standard vendor‐based reconstruction. The ⁶⁸Ga activities were decay corrected to the time of injection and normalized to the total activity administered.

No specific preparation was required for any of the subjects on the day of ⁶⁸Ga-FAPI-04 PET/CT scanning. A low-dose CT scan (120 kV, 35 mA, slice: 0.6 mm, matrix: 512 × 512) was performed before the ⁶⁸Ga-FAPI-04 injection; then, a whole-body dynamic PET scan was performed immediately after the intravenous injection of ⁶⁸Ga-FAPI-04 for all subjects and continued for 6 frames (frame 1, 5 mm/s; frame 2, 2 mm/s; frame 3, 2 mm/s; frame 4, 1.5 mm/s; frame 5, 1.5 mm/s; and frame 6, 1 mm/s), covering a period up to 60 min after the injection. All subjects underwent a follow-up 2-[¹⁸F]FDG PET/CT static scan within a week after ⁶⁸Ga-FAPI-04 imaging. The ⁶⁸Ga-FAPI-04 and 2-[¹⁸F]FDG PET/CT scans were acquired using a Biograph mCT Flow 64 scanner (Siemens, Erlangen, Germany) [120 kV, 146 mAs, slice: 3 mm, matrix: 200 × 200, full width at half maximum (FWHM): 5 mm, filter: Gaussian, field of view (FOV): 256 (head), 576 (body)], which continuously moved the patient bed to cover the entire body of each subject (from the top of the skull to the middle of the femur).