Abstract: A method of aligning multiple volumetric sections of imaging data is provided. The method comprises aligning a primary volumetric section and a secondary volumetric section which is adjacent to the primary volumetric imaging section, for moving the secondary volumetric section into alignment with the primary volumetric section. A related apparatus for performing the method is also provided.

Abstract: A time of flight positron emission tomography apparatus (100) includes a detector (106), a data acquisition system (120), a coincidence system (122) and a reconstructor (129). Various elements of an imaging chain influence the temporal resolution of the system (100) so that positron data collected along different lines of response is characterized by different temporal resolutions. The different temporal resolutions are used to estimate the positions of detected events along their respective lines of response.

Abstract: A nuclear imaging system includes a crystal identification system which receives a flood image which includes a plurality of peaks, each peak responsive to radiation detected by a corresponding scintillator crystal. A crystal identification processor partitions the flood image into a plurality of candidate regions with a watershed segmentator implementing a watershed algorithm. The candidate regions are linked in an adjacency graph, and then classified as background or relevant, where relevant regions contain a peak within the watershed lines. The regions are then assigned to a crystal according to an objective function and an assignability score. A calibration processor maps the peaks to a rectangular grid.

Abstract: A nuclear imaging system (10) includes a crystal identification system (40) which receives a flood image (30) which includes a plurality of peaks, each peak responsive to radiation detected by a corresponding scintillator crystal. A crystal identification processor (42) partitions the flood image (30) into a plurality of regions (56), each region being masked to correspond to one of an array of nuclear detectors. A model image (62) is generated in which the at least one Gaussian models represents the identified peaks. Misidentified peaks in the model image (62) in which locations of the peaks in the flood image (30) differ from the corresponding scintillator crystal are determined and the locations of the misidentified peaks in the flood image (30) are corrected. A calibration processor (43) corrects geometric distortions in acquired projection data according to the corrected peaks.

Abstract: A nuclear imaging system includes a crystal identification system which receives a flood image which includes a plurality of peaks, each peak responsive to radiation detected by a corresponding scintillator crystal. A crystal identification processor partitions the flood image into a plurality of candidate regions with a watershed segmentator implementing a watershed algorithm. The candidate regions are linked in an adjacency graph, and then classified as background or relevant, where relevant regions contain a peak within the watershed lines. The regions are then assigned to a crystal according to an objective function and an assignability score. A calibration processor maps the peaks to a rectangular grid.

Abstract: A nuclear imaging system (10) includes a crystal identification system (40) which receives a flood image (30) which includes a plurality of peaks, each peak responsive to radiation detected by a corresponding scintillator crystal. A crystal identification processor (42) partitions the flood image (30) into a plurality of regions (56), each region being masked to correspond to one of an array of nuclear detectors. A model image (62) is generated in which the at least one Gaussian models represents the identified peaks. Misidentified peaks in the model image (62) in which locations of the peaks in the flood image (30) differ from the corresponding scintillator crystal are determined and the locations of the misidentified peaks in the flood image (30) are corrected. A calibration processor (43) corrects geometric distortions in acquired projection data according to the corrected peaks.

Abstract: A method of aligning multiple volumetric sections of imaging data is provided. The method comprises aligning a primary volumetric section and a secondary volumetric section which is adjacent to the primary volumetric imaging section, for moving the secondary volumetric section into alignment with the primary volumetric section. A related apparatus for performing the method is also provided.

Abstract: A method for calibrating an imaging system includes coincident detecting scatter radiation events from a calibration source located within a bore of the imaging system. The scatter radiation events are subsequently used to compute calibration time offsets for each detector channel in the imaging system. Each detector channel is then calibrated with respective calibration time adjustments.

Abstract: A method and apparatus for calibrating a PET scanner is provided. First phantom sinogram data is acquired from a scan of a solid cylinder phantom within a PET scanner imaging FOV; second phantom sinogram data is acquired from a scan of a second solid plane or scanning line phantom within the PET scanner imaging FOV; and a PET scanner detector component scanner efficiency normalization is determined from at least one of the first and second sinogram data. In one aspect a crystal determining efficiency factor is determined as a function of phantom sinogram data without a solid angle correction, and a detector geometry factor is determined as a function of the crystal efficiency factor and phantom sinogram data. In one aspect a smoothed crystal efficiency normalization factor is determined from a noisy crystal efficiency factor through an iterative smoothing technique.

Abstract: A time of flight positron emission tomography apparatus (100) includes a detector (106), a data acquisition system (120), a coincidence system (122) and a reconstructor (129). Various elements of an imaging chain influence the temporal resolution of the system (100) so that positron data collected along different lines of response is characterized by different temporal resolutions. The different temporal resolutions are used to estimate the positions of detected events along their respective lines of response.

Abstract: A scintillator (18) includes radioactive elements which emit radiation of a characteristic energy, such as lutetium176, which emits 202 keV and 307 keV ?-rays. The scintillators have light output levels that vary and photomultiplier tubes that respond to the light scintillations tend to drift. When a scanner (10) is not generating diagnostic images, the photomultiplier tubes detect scintillations from the lutetium 176 radiation. A self-calibration processor (40) adjusts the gain for each photomultiplier tube such that its output peak corresponds to 202 keV or 307 keV and adjusts a scaling factor for PMT outputs corresponding to each scintillator such that the output peaks have a common amplitude.

Abstract: A method for calibrating an imaging system includes coincident detecting scatter radiation events from a calibration source located within a bore of the imaging system. The scatter radiation events are subsequently used to compute calibration time offsets for each detector channel in the imaging system. Each detector channel is then calibrated with respective calibration time adjustments.

Abstract: A scintillator (18) includes radioactive elements which emit radiation of a characteristic energy, such as lutetium176, which emits 202 keV and 307 keV ?-rays. The scintillators have light output levels that vary and photomultiplier tubes that respond to the light scintillations tend to drift. When a scanner (10) is not generating diagnostic images, the photomultiplier tubes detect scintillations from the lutetium 176 radiation. A self-calibration processor (40) adjusts the gain for each photomultiplier tube such that its output peak corresponds to 202 keV or 307 keV and adjusts a scaling factor for PMT outputs corresponding to each scintillator such that the output peaks have a common amplitude.

Abstract: A method and apparatus for calibrating a PET scanner is provided. First phantom sinogram data is acquired from a scan of a solid cylinder phantom within a PET scanner imaging FOV; second phantom sinogram data is acquired from a scan of a second solid plane or scanning line phantom within the PET scanner imaging FOV; and a PET scanner detector component scanner efficiency normalization is determined from at least one of the first and second sinogram data. In one aspect a crystal determining efficiency factor is determined as a function of phantom sinogram data without a solid angle correction, and a detector geometry factor is determined as a function of the crystal efficiency factor and phantom sinogram data. In one aspect a smoothed crystal efficiency normalization factor is determined from a noisy crystal efficiency factor through an iterative smoothing technique.

Abstract: A method for calibrating an imaging system includes coincident detecting scatter radiation events from a calibration source located within a bore of the imaging system. The scatter radiation events are subsequently used to compute calibration time offsets for each detector channel in the imaging system. Each detector channel is then calibrated with respective calibration time adjustments.

Abstract: A method of locating an event with a gamma camera (12) of an emission computed tomography (ECT) scanner (10) is provided. The gamma camera (12) includes a matrix of sensors (22) situated to view the event. The sensors (22) have respective outputs that are responsive to the event. The method includes: identifying a first sensor in the matrix that has in response to the event a highest output relative to the other sensors in the matrix (step (B2)); identifying a number of second sensors in the matrix that are closest neighbors to the first sensor (step (B3)); combining into a total output a number of outputs from the identified sensors, the number of outputs being at least one (1) and less than the number of all the identified sensors (step (B4)); and, determining a threshold value which is a percentage of the total output (step (B4)).