Biograph truepoint pet ct scanner

PET images were acquired following European guidelines (Varrone et al., 2009 (link)). Images were obtained in a Siemens Biograph True Point PET-CT scanner that integrates a 6-detector CT with a late-generation PET using lutetium oxyorthosilicate crystals. Patients fasted for at least 6 h before the scan. ¹⁸F-FDG (185 MBq) was administered intravenously 30 min before acquisition of images. During this period of time, patients remained at sensory rest. CT scan parameters were: kVp/effective mAs/rotation: 130/40/1; slice thickness: 3 mm; reconstruction interval: 1.5 mm; and pitch: 0.75. For PET acquisition, one bed position was obtained, and the acquisition time was 10 min.
Images were preprocessed using Statistical Parametric Mapping 8 software (https://www.fil.ion.ucl.ac.uk/spm/). They were realigned, and normalized to the Montreal Neurological Institute standard space using a specific FDG-PET template for cognitive disorders (Della Rosa et al., 2014 (link)). Global mean normalization was performed individually. Marsbar software was used to perform a region of interest analysis of 116 brain areas of the Automatic Anatomical Labeling atlas belonging to the whole brain. Thus, mean uptake values were obtained for each participant in 116 regions of interest.

Intravenous 0.1 mCi/kg ¹⁸F-FDG was administered to each patient following 6 hours of fasting, with a blood glucose level below 200 mg/dL. The intravenous/oral contrast agent was administered. After 45-60 minutes of waiting period, PET/CT images were acquired from the vertex to the upper thigh with Siemens Biograph True Point PET/CT scanner (CT section thickness 3 mm, 110 mAs, 120 kV; 3 minutes per-bed PET) (Siemens, Erlangen, Germany) at the PET/CT unit. Attenuation corrected PET, CT and fusion PET/CT images were reviewed simultaneously; visual and semiquantitative assessments were performed. The maximum standard uptake value (SUV_max) was the quantitative parameter used for ¹⁸F-FDG-PET scan. In visual assessment, bone marrow metabolic activity that is greater than the liver was considered to be pathologic. For semiquantitative assessment, regions of interest (ROI) were drawn for SUV_max estimation, which included iliac crest in cases with diffusely increased metabolic activity and the highest activity area in cases with focal involvement.