Biograph vision scanner

After fasting for a minimum of 8 h and resting for 10 min in a quiet room, patients received an intravenous dose of approximately 5 MBq/kg of ¹⁸F-FDG, followed by a 60-min uptake period. All patients had a serum glucose level less than 120 mg/dL at the time of injection. All ¹⁸F-FDG PET-CT examinations were performed on the Discovery STE scanner (GE Healthcare, Milwaukee, Wisconsin, USA) or the Biograph Vision scanner (Siemens Medical Solutions, Erlangen, Germany). Helical low dose, non-contrast CT images (tube voltage 100 kVp, current intensity 62 mAs, slice thickness 3.75 mm) were obtained for attenuation correction, similar to other groups [18 (link), 19 (link)]. PET images were acquired in three-dimensional mode and reconstructed to 128 × 128 image matrices using an iterative algorithm. Images were sent to our institution’s picture archiving and communications system (Sectra PACS, Sectra Medical, Linkoping, Sweden).

For [¹⁸F]flutemetamol, participants were injected with an average dose of 190.2 ± 14.3 MBq (BBRC cohort) or 179.4 ± 16.1 MBq (GMC cohort), and PET scans were acquired on a Siemens Biograph mCT or a Siemens Biograph Vision scanner. The remaining 75 participants from CHUT were injected with 302.9 ± 23.3 MBq [¹⁸F]florbetaben, and PET scans were acquired on a Siemens Biograph 4 Emission Duo LSO or Siemens Truepoint HiRez scanner (acquisition parameters can be found in Table 1). Prior to the PET scan, a non-diagnostic low-dose computed tomography (ldCT) scan was acquired on the same scanner for attenuation correction purposes. All scans were acquired in list-mode for 20 min, 90–110 min post radiotracer intravenous injection.