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: Methods and systems for signal processing in molecular imaging. The system may include at least one storage device including a set of instructions and at least one processor in communication with the storage device. The at least one processor may obtain a first signal that is acquired by sampling, according to a first sampling frequency, an electrical signal of a detector. The at least one processor may also generate, based on the first signal and a target machine learning model, a second signal, the second signal corresponding to a second sampling frequency that is different from the first sampling frequency. The target machine learning model may specify a target mapping between the first signal and the second signal. The at least one processor may further generate an image based on the second signal.

Abstract: A method and system for calibrating a PET scanner are described. The PET scanner may have a field of view (FOV) and multiple detector rings. A detector ring may have multiple detector units. A line of response (LOR) connecting a first detector unit and a second detector unit of the PET scanner may be determined. The LOR may correlate to coincidence events resulting from annihilation of positrons emitted by a radiation source. A first time of flight (TOF) of the LOR may be calculated based on the coincidence events. The position of the radiation source may be determined. A second TOF of the LOR may be calculated based on the position of the radiation source. A time offset may be calculated based on the first TOF and the second TOF. The first detector unit and the second detector unit may be calibrated based on the time offset.

Abstract: A method and system for calibrating a PET scanner are described. The PET scanner may have a field of view (FOV) and multiple detector rings. A detector ring may have multiple detector units. A line of response (LOR) connecting a first detector unit and a second detector unit of the PET scanner may be determined. The LOR may correlate to coincidence events resulting from annihilation of positrons emitted by a radiation source. A first time of flight (TOF) of the LOR may be calculated based on the coincidence events. The position of the radiation source may be determined. A second TOF of the LOR may be calculated based on the position of the radiation source. A time offset may be calculated based on the first TOF and the second TOF. The first detector unit and the second detector unit may be calibrated based on the time offset.

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.

Abstract: A method for positron emission tomography (PET) imaging may include obtaining photon information of photons that are emitted from an object and detected by detector units of a detector of a PET scanner. The method may also include obtaining, based on the photon information and lines of response (LORs), more than one coincidence window width value of the PET scanner. The method may also include determining coincidence events of the photons based on the more than one coincidence window width value.

Abstract: A method and system for calibrating a PET scanner are described. The PET scanner may have a field of view (FOV) and multiple detector rings. A detector ring may have multiple detector units. A line of response (LOR) connecting a first detector unit and a second detector unit of the PET scanner may be determined. The LOR may correlate to coincidence events resulting from annihilation of positrons emitted by a radiation source. A first time of flight (TOF) of the LOR may be calculated based on the coincidence events. The position of the radiation source may be determined. A second TOF of the LOR may be calculated based on the position of the radiation source. A time offset may be calculated based on the first TOF and the second TOF. The first detector unit and the second detector unit may be calibrated based on the time offset.

Abstract: A method and system for calibrating a PET scanner are described. The PET scanner may have a field of view (FOV) and multiple detector rings. A detector ring may have multiple detector units. A line of response (LOR) connecting a first detector unit and a second detector unit of the PET scanner may be determined. The LOR may correlate to coincidence events resulting from annihilation of positrons emitted by a radiation source. A first time of flight (TOF) of the LOR may be calculated based on the coincidence events. The position of the radiation source may be determined. A second TOF of the LOR may be calculated based on the position of the radiation source. A time offset may be calculated based on the first TOF and the second TOF. The first detector unit and the second detector unit may be calibrated based on the time offset.

Abstract: A method and system for calibrating a PET scanner are described. The PET scanner may have a field of view (FOV) and multiple detector rings. A detector ring may have multiple detector units. A line of response (LOR) connecting a first detector unit and a second detector unit of the PET scanner may be determined. The LOR may correlate to coincidence events resulting from annihilation of positrons emitted by a radiation source. A first time of flight (TOF) of the LOR may be calculated based on the coincidence events. The position of the radiation source may be determined. A second TOF of the LOR may be calculated based on the position of the radiation source. A time offset may be calculated based on the first TOF and the second TOF. The first detector unit and the second detector unit may be calibrated based on the time offset.