Vereos digital pet ct scanner

In total, 33 glioma patients (20 males, 28 surgically treated, of median age 55 year) admitted to our institution for a diagnosis or follow-up [¹¹C]MET PET scan were enrolled in this study. Patient’s clinical data, 2016 WHO classification, and undergone treatments at imaging time are provided for each lesion in Table A1. The patient cohort was further split into PCA model-building ( $n=20$ , patients 1 to 20 in Table A1) and evaluation ( $n=13$ , patients 21 to 33 in Table A1) sets (see Section 2.8). All patients underwent a 30 min and 30 s PET acquisition started 30 s before the intravenous injection of 287–555 MBq of [¹¹C]MET. All acquisitions were performed on a Vereos digital PET-CT scanner (Philips Healthcare, Best, The Netherlands) with an axial and trans-axial resolution of 4.1 mm at 1 cm from the field-of-view center. In total, 906 overlapping frames of 20 s, spaced by 2 s with a voxel size of 2 mm × 2 mm × 2 mm were reconstructed from the LIST files using time-of-flight ordered subset expectation maximization (TOF-OSEM, 10 subsets and 3 iterations) with computed tomography-based attenuation correction (CTAC). No post-reconstruction filter was applied to the dynamic frames. A routine static PET image (20–27 min post-injection (p.i.)) was also reconstructed for each patient (2 mm × 2 mm × 2 mm—CTAC TOF-OSEM, 15 subsets and 3 iterations—no filter).

The L-[methyl-11C] methionine radiotracer was synthesized utilizing an on-site cyclotron (GE PETtrace; GE Healthcare, Chicago, IL, USA). To ensure stable baseline metabolic conditions, all patients underwent a 4 h fasting period before scanning. Subsequently, patients received injections ranging from 370 to 555 MBq of 11C-methionine on the scan day.
To minimize potential confounding effects, patients were instructed to limit physical activity, followed by a 10 min rest period post-injection. Approximately 10 min after injection, low-dose transmission CT images were acquired to facilitate brain attenuation correction for the PET emission data and provide morphological information.
Whole-brain emission data were acquired in three-dimensional mode, 15–20 min post-injection of 11C-MET, utilizing a Philips Vereos Digital PET/CT scanner (Philips Healthcare, Amsterdam, the Netherlands). This comprehensive imaging protocol ensured optimal visualization and quantification of metabolic activity within the brain tissue.

All PET scans were acquired using a Philips Vereos Digital PET/CT scanner (Philips Healthcare, Best, The Netherlands) with 3D emission acquisition. First, a 5 min transmission scan was also performed to enable attenuation correction. Next, following an intravenous bolus injection of ¹¹C-PIB, a 70 min dynamic PET scan was acquired (frames: 4 × 15 s, 8 × 30 s, 9 × 60 s, 2 × 180 s and 10 × 300 s). Data from the PET scans were reconstructed with a 3D-FRP (direct Fourier method with Fourier reprojection) algorithm for dynamic and a 3D-ordered subset expectation maximum algorithm for static analyses, achieving an isotropic 2.0 mm reconstructed image spatial resolution.