Ge discovery vct pet ct scanner

⁶⁸Ga-DOTA-peptides were synthesized as previously described [12 (link)]. Radiochemical purity and specific activity (mean) was 99.9% and 31.5 GBq/μmol for ⁶⁸Ga-DOTANOC, and 96.5% and 26.8 GBq/μmol for ⁶⁸Ga-DOTATOC, respectively. PET/CT of the brain was performed using a GE Discovery VCT PET/CT Scanner (General Electric Medical Systems, Pewaukee, WI, USA). Dynamic PET was acquired over 60 min (8 × 15-, 6 × 30-, 5 × 180-, 4 × 300-, and 2 × 600-s frames) after intravenously injected ⁶⁸Ga-DOTANOC (123 MBq, median) or ⁶⁸Ga-DOTATOC (130 MBq, median). Low-dose CT (120 kV, 10 to 95 mA, noise index 25, slice thickness 3.75 mm) was used for attenuation correction. PET images were reconstructed (256 × 256 matrix, OSEM3D, 3 iterations, 28 subsets, 4.8-mm Hanning postfilter) yielding a pixel size of 1.4 mm. A duration of 60 min was determined after 90-min dynamic PET performed to one patient (no. 13) and 5-min static scans performed to three patients (nos. 11, 12, and 23) 96 min post-injection confirmed that tumor uptake did not increase after 60 min.
Clinical preoperative MRI nearest in time to PET scan (mean interval 14 days) was employed, and post-contrast T1-weighted images (MRI-T1-Gad) were used to define the tumor volume with contrast enhancement. MRI scanners and parameters used are listed in Online Resource 1.

¹⁸F-FDG PET/CT scans were acquired on a GE Discovery VCT PET/CT scanner (GE Healthcare, Waukesha, WI, USA) in accordance with EANM procedure guidelines for tumor imaging [31 (link)] and EANM/SNMMI guidelines for ¹⁸F-FDG use in inflammation and infection [32 (link)]. Patient preparation with at least 4 or 6 h of fasting prior to the administration of ¹⁸F-FDG, blood glucose levels lower than 11 mmol/l, and a resting time of approximately 60 min after tracer injection were obligatory. The mean injected activity of ¹⁸F FDG was 370 MBq. The CT portion was acquired with a low dose and 0.65–5.0 mm slice thickness. Corrected and uncorrected transaxial, sagittal, and coronal images were acquired with an iterative reconstruction algorithm and an existing metal artifact reduction algorithm.

¹¹C-DHE, 10–20 mCi, was injected as an intravenous bolus. Arterial blood samples were taken at the following time points: 1, 2, 3, 4, 5, 10, 15, 30, 45, and 60 min. Dynamic PET scans were acquired over 60 min using a GE Discovery VCT PET/CT scanner (GE Healthcare) in 3D mode with septa retracted. A low-mA CT scan prior to the PET was used for attenuation correction. Images were reconstructed by 3D iterative reconstruction into 47 image planes (separation 3.27 mm) and into a 128 × 128 image matrix (pixel size: 2.1 × 2.1 mm
²).