Discovery st pet ct scanner

The control group comprised 39 healthy adult controls aged between 21 and 59 years (mean 40, SD 11). The scans were provided by the Department of Nuclear Medicine, Assistance Publique Hôpitaux de Marseille and were acquired after a 4–6 h fast on a GE Discovery ST PET-CT scanner over 15 min after bolus intravenous injection of 150 MBq of FDG and a 30-min uptake period (with eyes closed) and reconstructed via OSEM (ClinicalTrials reference: NCT00484523). These healthy subjects were free of neurological/psychiatric symptoms or antecedent diagnosis, had a normal neuropsychological evaluation, and a normal brain MRI. This control PET database was ethically approved by CPP Sud Mediterranée (2007-A00180-53).

Subjects underwent a PET scan 90 min after intravenous injection of 300 MBq ¹⁸F-florbetaben using a dedicated Discovery ST PET-CT scanner (General Electric Medical Systems, Milwaukee, WI, USA). Non-contrast-enhanced computed tomography (CT) scans were used for attenuation correction with technical parameters of 120 Kvp, 10–130 mAs, eight slices, helical, and 3.79 mm slice thickness. PET and CT scan data were reconstructed using ordered subset expectation maximization after attenuation correction with two iterations and 21 subsets. A Gaussian filter was applied with 5.14 mm FWHM to reconstruct a 128 × 128 matrix with 3.27-mm slice thickness.

A PET scan using [¹⁸F]THK5317 and a 3D-T1-weighted MRI sequence were acquired for all participants. Additionally, all participants except the yHC group underwent a [¹¹C]PIB-PET scan, and all patients (i.e. those with prodromal AD, AD dementia, MCI PIB-negative, and non-AD dementia) underwent an [¹⁸F]FDG-PET scan.
The [¹⁸F]THK5317- and [¹¹C]PIB-PET scans were acquired on an ECAT EXACT HR+ scanner (Siemens/CTI) or a Discovery ST PET/CT scanner (GE) at the Uppsala PET centre, Uppsala, Sweden. Both tracers were synthesised according to standard good manufacturing processes as previously described [11 , 20 (link)]. For [¹⁸F]THK5317-PET, 22 frames were acquired over 60 min (6 × 10 s, 3 × 20 s, 2 × 30 s, 2 × 60 s, 2 × 150 s, 4x300 s, and 3x600 s frames) after intravenous injection of 212 ± 42 MBq. For [¹¹C]PIB-PET, 24 frames were acquired over 60 min (4 × 30s, 9 × 60 s, 3 × 180 s and 8 × 300 s) after intravenous injection of 253 ± 69 MBq. The [¹⁸F]FDG-PET scans were acquired on a Biograph mCT PET/CT scanner (Siemens) at the Department of Nuclear Medicine, Karolinska University Hospital Huddinge, Stockholm, Sweden, with a 15 min static run, 30 min after injection (30–45 min) of 3 MBq/kg. All acquisitions were reconstructed using ordered subset expectation maximisation.

As detailed previously [14 (link)], PET-CT scan was carried out with a Discovery ST PET/CT scanner (GE Medical Systems; Waukesha, WI, USA) at the Yotsuya Medical Cube (Tokyo Japan). Two experienced nuclear medicine radiologists (W. K. and M. A.) evaluated the PET-CT images, side by side, and reached a consensus on the findings.

The imaging technique was performed according to a recommended clinical protocol [11 (link)]. The patients were well hydrated and requested to empty their bladder directly before scanning. Examination was performed after intravenous administration of 3 MBq/kg of 18F-labeled sodium fluoride at 1 h after injection.
Examinations were performed on a Discovery ST PET/CT Scanner (GE Healthcare, Waukesha, WI): field of view (FOV) of 15.7 cm in axial and 70 cm in transaxial direction and slice thickness of 3.27 mm. Patients were positioned supine with arms elevated. An unenhanced CT (40–80 mA) from mid-thigh to vertex of the skull was used for attenuation correction. Images were acquired in 3D mode with an acquisition time of 3 min/bed position. The images were reconstructed iteratively with ordered subset expectation maximisation (2 iterations, 21 subsets, 5 mm Gaussian post-filter), applying all relevant corrections according to the recommendations of the manufacturer, to a 128 × 128 matrix in a 50-cm FOV and fused with unenhanced CT.