FDG PET Imaging Acquisition Protocol

FDG PET images were acquired using a 3-dimensional GE Discovery 690 PET/CT scanner or a Siemens ECAT EXACT HR + PET scanner. All patients fasted for at least 6 h prior to scanning, and had a maximum plasma glucose level of 120 mg/dl at time of [¹⁸F]-FDG administration. A dose of 140 ± 7 MBq [¹⁸F]-FDG was injected intravenously in resting conditions, in a room with dimmed light and low noise level. A static emission frame was acquired from 30 min to 45 min p.i. for the GE Discovery 690 PET/CT, or from 30 to 60 min p.i. for the Siemens ECAT EXACT HR + PET scanner. A low-dose CT scan or a transmission scan with external ⁶⁸Ge-sources was performed prior to the static acquisition and was used for attenuation correction. PET data were reconstructed iteratively (GE Discovery 690 PET/CT, voxel size 2.34 × 2.34 × 3.27 mm, 3D recon with a 4.5 mm Gaussian post filter) or with filtered backprojection (Siemens ECAT EXACT HR + PET, voxel-size 2.03 × 2.03 × 2.42 mm with a 2.42 mm Hann filter). This resulted in datasets with comparable resolution (Joshi et al., 2009 (link)).