A method for daily setup and quality checks of LSO:Ce based time of flight positron emission tomographs

The setup of PET scanners usually requires an external positron source. A correct setup procedure has to ensure that the detectors are calibrated for gain adjustments, photopeak locations, and positioning maps for individual detector crystals. In order to verify the quality of the setup on a daily basis, daily quality checks are performed where the variations are checked with an external source and flagged if a new setup should be performed. Performing equivalent checks and calibrations using the intrinsic radiation of LSO have successfully been studied previously. Using additional information given by the time of flight information, the intrinsic source originating from the isotope 176Lu can create very accurate setup data within time durations allowing daily scheduling of data collection. The addition of time of flight information also gives an intrinsic method to check the timing calibration essential to time of flight PET scanners. This intrinsic automated setup and quality checks are performed daily without the need of an operator or mechanical devices, creating a consistent condition that data is collected in.