Abstract: The present disclosure is related to systems and methods for data masking. The method includes obtaining data associated with coincidence events related to intrinsic background radiations of a plurality of crystals of the PET device. Each of the coincidence events may be detected by two crystals of the plurality of crystals of the PET device. The data associated with the each coincidence event may include first time information and second time information. The method includes determining a first time of fight (TOF) difference corresponding to the each coincidence event based on the first time information and the second time information. The method includes determining a second TOF difference corresponding to the each coincidence event based on locations of the two crystals that detect the each coincidence event. The method includes correcting the PET device based on the first TOF difference and the second TOF difference.

Abstract: The embodiments of the present disclosure provide a state detection method and system for an imaging device. The method includes: obtaining a first background event of a crystal of a detector of the imaging device, the first background event being related to an inherent radiating particle of the crystal; correcting a crystal position look-up table based on the first background event; correcting an energy state of the imaging device; obtaining the second background event of the crystal, the second background event being related to the inherent radiating particle of the crystal; and correcting a state of time of flight of the detector based on the first background event and the second background event.