True point biograph 16

All patients were examined with a whole-body PET scanner, GE Advance (GE Healthcare, Waukesha, WI, USA), or with a whole-body PET/CT scanner, Siemens True Point Biograph 16 (Siemens/CTI, Erlangen, Germany). All subjects received an intravenous injection of MeAIB (513.6 ± 65.6 MBq) or MET (533.9 ± 35.0 MBq). Brain PET/CT images were acquired 20 min after the radiotracer injection in 1 bed position in both study. Emission images were acquired for 5 min per bed position. The data were reconstructed using the ordered subsets expectation-maximization method using eight subsets, two iterations, and an array size of 256 × 256. For the attenuation correction of PET/CT fusion images, the CT component was performed according to a standard protocol with the following parameters: 140 kV; 50 mAs; tube rotation time, 0.5 s per rotation; slice thickness, 5 mm; and gap, 2 mm. An E-soft workstation (Siemens, Nashville, TN, USA) was used to construct PET/CT fusion images.

Chest CT scans were performed using a single source 32‐detector or 64‐detector CT scanner (Aquilion 32 or 64, Toshiba Medical Systems, Otawara, Japan). The settings were as follows: 1 mm collimation, 0.5 second rotation time, 27 or 53 pitch (ratio of table movement per rotation to total beam width), and 120 kV. The noise level was set at 10 standard deviations using automatic tube current modulation (z‐axis modulation with Real E.C. technique, Toshiba Medical Solutions). All PET‐CT images were obtained using a PET‐CT scanner (True Point Biograph 16, Siemens Healthcare, Tokyo, Japan). Patients received an intravenous administration of 4.0 MBq/kg 18F‐FDG in the sitting position after fasting for 6 hours, and a PET‐CT scan 60 minutes later. Chest CT images were reviewed by two pulmonologists (KU and SH) who were blinded to the results of the final pathological diagnoses, as well as the BSIs and EEIs. PET‐CT images were evaluated by an independent and blinded radiologist.