Optimizing Imaging Protocols for Overweight and Obese Patients: A Lutetium Orthosilicate PET/CT Study

High photon attenuation and scatter in obese patients affect image quality. The purpose of the current study was to opti-mize lutetium orthosilicate (LSO) PET image acquisition pro-tocols in patients weighing 91 kg (200 lb). Methods: Twen-ty-five consecutive patients (16 male and 9 female) weighing 91 kg (200 lb; range, 91–168 kg [200–370 lb]) were studied with LSO PET/CT. After intravenous injection of 7.77 MBq (0.21 mCi) of 18F-FDG per kilogram of body weight, PET emission scans were acquired for 7 min/bed position. Single-minute frames were extracted from the 7 min/bed position scans to reconstruct 1–7 min/bed position scans for each patient. Three reviewers independently analyzed all 7 recon-structed whole-body images of each patient. A consensus reading followed in cases of disagreement. Thus, 175 whole-body scans (7 per patient) were analyzed for number o