Abstract: A method of determining component misalignment in a multi-modality imaging system includes imaging a plurality of target objects with a first modality unit to generate a tomographic image data set and imaging the plurality of targets with a second modality unit to generate an emission image data set. The method also includes determining a location of the target objects in the emission image data set to produce emission target object location coordinates, calculating a positional alignment vector for each target object based on the emission target object location coordinates, and aligning the multi-modality imaging system based on the positional alignment vectors.

Abstract: A method of determining component misalignment in a multi-modality imaging system includes imaging a plurality of target objects with a first modality unit to generate a tomographic image data set and imaging the plurality of targets with a second modality unit to generate an emission image data set. The method also includes determining a location of the target objects in the emission image data set to produce emission target object location coordinates, calculating a positional alignment vector for each target object based on the emission target object location coordinates, and aligning the multi-modality imaging system based on the positional alignment vectors.

Abstract: Methods and systems for calibrating a positron emission tomography (PET) system are provided. The method includes determining at least one non-acquisition time period for the PET system. The method further includes automatically acquiring calibration data during the at least one non-acquisition time period.

Abstract: Methods and systems for controlling a positron emission tomography (PET) system are provided. The method includes receiving timing information from a PET system during an imaging scan using the PET system. The method further includes processing the received timing information and timing bias information relating to the PET system to control the PET system.

Abstract: Methods and apparatus for correcting for at least one of deadtime losses and random coincidences in a positron emission tomography (PET) medical imaging device having a plurality of detectors at successive locations circumferentially spaced about a viewing area, the method comprising, receiving signals indicative of positron-electron annihilation events occurring along a line of response between pairs of detectors for a plurality of predetermined time segments of data acquisition of the events, calculating a correction sinogram for each predetermined time segment from data acquired during each respective single time segment, calculating corrected counts in the correction sinogram for each time segment, calculating a time-weighted correction sinogram for each time segment, combining the time-weighted correction sinogram to generate an acquisition sinogram, and generating an image from the acquisition sinogram.

Abstract: The invention is directed to a method and apparatus for timing calibration in a PET scanner. According to one embodiment, the invention relates to a method for timing calibration in a PET scanner having a plurality of scintillator blocks. The method comprises: detecting, in a first scintillator block, a first radiation event, wherein the first scintillator block time-stamps the first radiation event; detecting, in a second scintillator block that is adjacent to the first scintillator block, a second radiation event that corresponds to the first radiation event, wherein the second scintillator block time-stamps the second radiation event; and determining a timing characteristic of the first scintillator block with respect to the second scintillator block based on a comparison between the time-stamps of the first radiation event and the second radiation event.

Abstract: The invention relates to a system and method for generating a detector position map for an array of detectors. The detector position map comprises a map which converts measured position coordinates from a detection event to the detector in the array which detected the detection event. The method comprises the steps of illuminating an array of detectors with a source of radiation to generate a histogram, the histogram comprising an event count as a function of two dimensions, the two dimensions corresponding to a face of the array of detectors, wherein the histogram comprises a plurality of first peaks; modifying the histogram to comprise a plurality of second peaks, wherein the second peaks have a greater degree of isolation from each other than the first peaks; and for each detector, determining a region on the detector position map which corresponds to the detector, each region being based on a position of one of the second peaks.

Abstract: A method and apparatus for calibrating PET PMTs includes conducting a calibration procedure and determining whether a number of photons absorbed by a corresponding crystal exceeds a count threshold. If the threshold is exceeded the steps of conducting a calibration procedure and determining whether a number of photons absorbed by a corresponding crystal exceeds a count threshold would be repeated and if the threshold is not exceeded then the calibration procedure would be ended.

Abstract: A method and apparatus for eliminating the picket fence effect in PET scanners where the scanner includes a master clock and an event processing circuit that generates time stamps during each clock cycle, the scanner also including a coincidence detector that compares the time stamps during each clock cycle to identify coincidence events, the method including the steps of, for consecutive master clock cycles, identifying an overlap period that includes a portion of a first of the master cycles adjacent a second of the master cycles, adding an overlap period that occurs during the overlap period to the second of the master cycles to generate an extended cycle, identifying overlap events that occur during the overlap period in the first of the master cycles, copying the overlap events to the overlap period in the extended second cycle and performing a comparison of the events in the extended cycle to identify coincidence event pairs

Abstract: A method and apparatus for calibrating PET PMTs includes conducting a calibration procedure and determining whether a number of photons absorbed by a corresponding crystal exceeds a count threshold. If the threshold is exceeded the steps of conducting a calibration procedure and determining whether a number of photons absorbed by a corresponding crystal exceeds a count threshold would be repeated and if the threshold is not exceeded then the calibration procedure would be ended.

Abstract: A method and apparatus for calibrating PET PMTs, the method including, during a commissioning process, determining gain factors for each crystal in a detector unit that cause the peak energy level in a crystal energy spectrum to be equal to a target value and, during a calibration process, generating energy spectrums for each crystal in the unit, combining the gain factors and crystal spectrums to generate shifted crystal spectrums, combining the shifted spectrums to generate a unit spectrum, identifying the peak unit spectrum energy level and comparing the peak unit level to the target value to generate PMT adjustment levels.

Abstract: A method and apparatus for eliminating the picket fence effect in PET scanners where the scanner includes a master clock and an event processing circuit that generates time stamps during each clock cycle, the scanner also including a coincidence detector that compares the time stamps during each clock cycle to identify coincidence events, the method including the steps of, for consecutive master clock cycles, identifying an overlap period that includes a portion of a first of the master cycles adjacent a second of the master cycles, adding an overlap period that occurs during the overlap period to the second of the master cycles to generate an extended cycle, identifying overlap events that occur during the overlap period in the first of the master cycles, copying the overlap events to the overlap period in the extended second cycle and performing a comparison of the events in the extended cycle to identify coincidence event pairs

Abstract: A method and apparatus for calibrating PET PMTs, the method including, during a commissioning process, determining gain factors for each crystal in a detector unit that cause the peak energy level in a crystal energy spectrum to be equal to a target value and, during a calibration process, generating energy spectrums for each crystal in the unit, combining the gain factors and crystal spectrums to generate shifted crystal spectrums, combining the shifted spectrums to generate a unit spectrum, identifying the peak unit spectrum energy level and comparing the peak unit level to the target value to generate PMT adjustment levels.