Gemini dual slice exp scanner

All patients underwent FDG PET/CT on the same PET scanner (Philips Gemini Dual-slice EXP scanner, PET AllegroTM system with Brilliance CT scanner, Philips Medical Systems, Cleveland, OH). The median time interval between PET imaging and biopsy was 1.5 months (0–6 months). In accordance with the procedure guidelines for PET imaging [29 (link)], the injected 18F-FDG activity was 242 +/− 52 MBq (range, 148–393 MBq). After 60 min of uptake and following free-breathing CT acquisition for attenuation correction from the vertex of the skull to the mid-thigh (5 mm slice, 40 mAs and 120 kVp), PET data were acquired in 3-dimensional (3D) mode, covering the same anatomical region of the CT, with 2.5 min per bed position and 6–8 bed positions per patient. The PET scans were reconstructed by the ordered subset expectation maximization (OSEM) algorithm (3D-RAMLA), with the following settings: 4 iterations, 8 subsets, and a field of view (FOV) of 576 mm. For all reconstructions, the matrix size was 144 × 144 voxels, resulting in isotropic voxels of 4.0 × 4.0 × 4.0 mm³. All acquisitions were corrected for attenuation (using the corresponding CT image), as well as for scatter and random coincidences.

All patients underwent PET/CT on an analog 3-dimensional (3D) PET scanner (Philips Gemini Dual-slice EXP scanner—PET Allegro^TM system with Brilliance CT scanner—Philips Medical Systems, Cleveland, OH). In accordance with the procedural guidelines for PET imaging [36 (link)–38 (link)], the injected tracer activity was 145.1 ± 25.3 MBq of ⁶⁸Ga-DOTA-TOC (range, 100–212 MBq). After 60 min of uptake and following free-breathing CT acquisition for attenuation correction from the vertex of the skull to the mid-thighs (5 mm slice, 40 mAs, and 120 kVp), PET data were acquired in 3-dimensional (3D) mode, covering the same anatomical region of the CT, with 2.5 min per bed position and 6–8 bed positions per patient. The PET scans were reconstructed by ordered subset expectation maximization (OSEM) algorithm (3D-RAMLA), with the following settings: 4 iterations, 8 subsets, and field of view (FOV) of 576 mm. For all reconstructions, matrix size was 144 × 144 voxels, resulting in isotropic voxels of 4.0 × 4.0 × 4.0 mm³. All acquisitions were corrected for photon attenuation (using the corresponding CT image), as well as for scatter and random coincidences.