*2.4. 18F-FDG PET/CT Imaging Procedure*

Patient preparation for 18F-FDG PET/CT included a minimum of 4 h of fasting which is in keeping with published guidelines [25,26]. Blood sugar before 18F-FDG injections was less than 7.1 mmol/L in all cases. The injected activity of 18F-FDG was between 3–5 MBq/kg. We imaged patients after an uptake period of 60 min. Thirteen of the patients were imaged on a Biograph 40 Truepoint PET/CT scanner (Siemens Medical Solutions, Lincolnshire, IL, USA), while the other seven were imaged on a Biograph Vision 450 PET/CT scanner (Siemens Medical Solutions, Lincolnshire, IL, USA). We performed a vertex to mid-thigh CT scan with parameters adjusted for patients' weight (120 KeV, 40–150 mAs) with a section width of 5 mm and pitch of 0.8.
