Discovery pet ct 690

Detailed FDG-PET/CT acquisition protocols have been reported previously [14 (link), 15 (link)]. In brief, fasting patients with a blood glucose serum concentration below 12 mmol/l were injected with a standardised dose of 18F-FDG, according to our institution’s protocol. After the injection, the patients rested for one hour in supine position in a warm environment. Scanning was performed using integrated PET/CT systems (Discovery MI PET/CT or Discovery PET/CT 690, GE Healthcare, Waukesha, WI, USA).
OPTs were generated in a standing position, with the head oriented to the Frankfurt plane, using a Cranex 3D (Soredex, KaVo, Biberach, Germany). Periapical radiographs were generated using a Heliodent DS (Dentsply-Sirona, Bensheim, Germany) intraoral X-ray, operating at 60 kV and 7 mA. The parallel technique was used with a focus-patient distance of approximately 21 cm.

PET/CT acquisitions were performed on a GE Discovery PET/CT 690. The time between injection and imaging was (64 ± 5) min. Images were acquired from head to mid-thigh, with acquisition time 3 min per bed position. Tomographic images were reconstructed with an in-plane matrix size of 192 × 192 and voxel size 3.65 × 3.65 × 3.27 mm³, using time-of-flight information and OS-EM with 3 iterations and 12 subsets, compensation for attenuation and scatter, three-dimensional point-spread function (PSF) modelling (referred to as VPFX-S on the camera system), a transaxial 5 mm full width at half maximum (FWHM) Gaussian post-filter, and an axial z-filter.

Each patient underwent a three-dimensional PET/CT scan from skull base to
mid-thigh approximately 60 min after injection of 370 MBq (10 mCi) of
¹⁸F-FDG. Images were obtained on a PET/CT scanner with
time-of-flight technology (Discovery PET/CT 690; GE Healthcare, Milwaukee, WI,
USA). The PET images were acquired for 3 min per bed position (15-cm slice
thickness with a 3-cm overlap). The iterative technique with 24 subsets was used
for PET image reconstruction in all studies. For attenuation correction and
diagnostic purposes, we obtained non-contrast-enhanced CT transmission scans
using the following parameters: current, 125 mAs; voltage, 120 kVp; gantry
rotation, 0.5 s; pitch, 1.375; and axial slice thickness, 3.75 mm.

[¹⁸F]FDG-PET/CT image acquisition was performed according to the European Association of Nuclear Medicine (EANM) guidelines (Boellaard et al. 2014 (link)). Images were acquired 60 ± 5 min after [¹⁸F]FDG administration, in the fasting state using an integrated PET/CT scanner, either a Siemens Biograph LS 6 scanner (Siemens, Munich, Germany) equipped with LSO crystals and a six-slice CT scanner, or a GE Discovery PET/CT 690 equipped with LYSO crystals and a 64-slice CT scanner (General Electric Healthcare, Waukesha, WI, USA). Both scanners are EARL certified (http://www.eanm.org) and images were processed in order to minimize differences between semi-quantitative evaluation.

The specimens were collected at autopsy and consent was obtained to authorize the use of specimens for research purposes. We obtained all de-identified pathological specimens with an extracardiac Fontan PTFE conduit (GORE-TEX®) available within our institution (Nationwide Children’s Hospital; IRB STUDY00003038). These samples were not separately consented for this particular research. The majority of them were collected at the time of autopsy – not surgery. They were collected for non-human subjects research under a general autopsy consent, indicating the following: “I authorize the removal, examination, and retention of specimens including tissue, organs (including the brain), fluids, and devices (“Autopsy specimens”) for diagnostic, education, quality improvement, and or research purposes”. Patient demographics were obtained, gross pathological images were taken, and computed tomography (CT) scans of the entire pathological specimen were acquired with a slice thickness of 0.625 mm, at 450 mA, and 120 kVp using a commercially available clinical scanner (Discovery PET/CT 690, GE Healthcare). After scanning the pathological specimen, a section of the conduit was obtained and Von Kossa staining was carried out. Images were obtained using the Nikon AX R confocal imaging system.