Abstract: A computer-implemented method for penalized-likelihood reconstruction of a Positron Emission Tomography (PET) image includes generating a regularization function in which a smoothing parameter is modulated by one or more data-independent spatially variable modulation factors to compensate for sensitivity variations in a PET voxel dataset, and reconstructing the PET image from the PET emission dataset using the regularization function.

Abstract: A computer-implemented method for partial volume correction in Positron Emission Tomography (PET) image reconstruction includes receiving emission data related to an activity distribution, reconstructing the activity distribution from the emission data by maximizing a penalized-likelihood objective function to produce a reconstructed PET image, quantifying an activity concentration in a region of interest of the reconstructed PET image to produce an uncorrected quantitation, and correcting the uncorrected quantitation based on a pre-calculated contrast recovery coefficient value to account for a partial volume error in the uncorrected quantitation.

Abstract: Systems and methods for attenuation compensation in nuclear medicine imaging based on emission data are provided. One method includes acquiring emission data at a plurality of energy windows for a person having administered thereto a radiopharmaceutical comprising at least one radioactive isotope. The method also includes performing a preliminary reconstruction of the acquired emission data to create one or more preliminary images of a peak energy window and a scatter energy window and determining a body outline of the person from at least one of the reconstructed preliminary image of the peak energy window or of the scatter energy window. The method further includes identifying a heart contour and segmenting at least the left lung. The method additionally includes defining an attenuation map based on the body outline and segmented left lung and reconstructing an image of a region of interest of the person using an iterative joint estimation reconstruction.

Abstract: A computer-implemented method for partial volume correction in Positron Emission Tomography (PET) image reconstruction includes receiving emission data related to an activity distribution, reconstructing the activity distribution from the emission data by maximizing a penalized-likelihood objective function to produce a reconstructed PET image, quantifying an activity concentration in a region of interest of the reconstructed PET image to produce an uncorrected quantitation, and correcting the uncorrected quantitation based on a pre-calculated contrast recovery coefficient value to account for a partial volume error in the uncorrected quantitation.

Abstract: A computer-implemented method for penalized-likelihood reconstruction of a Positron Emission Tomography (PET) image includes generating a regularization function in which a smoothing parameter is modulated by one or more data-independent spatially variable modulation factors to compensate for sensitivity variations in a PET voxel dataset, and reconstructing the PET image from the PET emission dataset using the regularization function.

Abstract: A Nuclear Medicine (NM) imaging system and method using multiple types of imaging detectors are provided. One NM imaging system includes a gantry, at least a first imaging detector coupled to the gantry, wherein the first imaging detector is a non-moving detector, and at least a second imaging detector coupled to the gantry, wherein the second imaging detector is a moving detector. The first imaging detector is larger than the second imaging detector and the first and second imaging detectors have different detector configurations. The NM imaging system further includes a controller configured to control the operation of the first and second imaging detectors during an imaging scan of an object to acquire Single Photon Emission Computed Tomography (SPECT) image information such that at least the first imaging detector remains stationary with respect to the gantry during image acquisition.

Abstract: Systems and methods for attenuation compensation in nuclear medicine imaging based on emission data are provided. One method includes acquiring emission data at a plurality of energy windows for a person having administered thereto a radiopharmaceutical comprising at least one radioactive isotope. The method also includes performing a preliminary reconstruction of the acquired emission data to create one or more preliminary images of a peak energy window and a scatter energy window and determining a body outline of the person from at least one of the reconstructed preliminary image of the peak energy window or of the scatter energy window. The method further includes identifying a heart contour and segmenting at least the left lung. The method additionally includes defining an attenuation map based on the body outline and segmented left lung and reconstructing an image of a region of interest of the person using an iterative joint estimation reconstruction.

Abstract: A Nuclear Medicine (NM) imaging system and method using multiple types of imaging detectors are provided. One NM imaging system includes a gantry, at least a first imaging detector coupled to the gantry, wherein the first imaging detector is a non-moving detector, and at least a second imaging detector coupled to the gantry, wherein the second imaging detector is a moving detector. The first imaging detector is larger than the second imaging detector and the first and second imaging detectors have different detector configurations. The NM imaging system further includes a controller configured to control the operation of the first and second imaging detectors during an imaging scan of an object to acquire Single Photon Emission Computed Tomography (SPECT) image information such that at least the first imaging detector remains stationary with respect to the gantry during image acquisition.

Abstract: A method for determining the effectiveness of an image transformation process includes acquiring a four-dimensional (4D) image data set, sorting the 4D image data set into separate field-of-view bins using a temporal gating system generating a plurality of deformation vectors using the sorted 4D image data set, and using the plurality of deformation vectors to generate a transformation effectiveness value that is representative of the effectiveness of the image transformation process. The method further includes acquiring a respiratory signal, calculating a power spectrum of the respiratory signal, calculating a power spectrum for each of the plurality of deformation vectors, and comparing the power spectrum of the respiratory signal to the power spectrum of the plurality of deformation vectors to generate the transformation effectiveness value.

Abstract: A region of interest is automatically evaluated. The automatic evaluation is based on assessments of one or more characteristics. The one or more characteristics of the region of interest are assessed in a plurality of image data sets acquired by a respective plurality of imaging modalities. In some embodiments, the evaluation is based on assessments of one or more characteristics for each region of interest derived from a combination of structural and functional image data. In one embodiment, the set of structural image data is a set of CT image data and the set of functional image data is a set of PET image data. The one or more lesions may be detected in the structural and/or functional image data by automated routines or by a visual inspection by a clinician or other reviewer.

Abstract: A method for determining the effectiveness of an image transformation process includes acquiring a four-dimensional (4D) image data set, sorting the 4D image data set into separate field-of-view bins using a temporal gating system generating a plurality of deformation vectors using the sorted 4D image data set, and using the plurality of deformation vectors to generate a transformation effectiveness value that is representative of the effectiveness of the image transformation process. The method further includes acquiring a respiratory signal, calculating a power spectrum of the respiratory signal, calculating a power spectrum for each of the plurality of deformation vectors, and comparing the power spectrum of the respiratory signal to the power spectrum of the plurality of deformation vectors to generate the transformation effectiveness value.

Abstract: A method and system for calibrating a time of flight (TOF) positron emission tomography (PET) scanner are provided. The method stores acquired scan data from detector pairs including data and timing information. The method further calculates an intensity distribution of emission sources based on the scan data and defines a timing pivot point based on a median of an intensity histogram. The method determines a timing correction for each detector based on the location of the timing pivot point. The positron emission tomography (PET) system further provides a plurality of detectors, used in performing imaging scans, and a processor. The processor is configured to determine a timing correction for each detector.

Abstract: A malignancy probability is automatically calculated for one or more lesions. The malignancy probability is based on assessments of one or more malignancy characteristics for each lesion derived from two or more structural and/or functional image data sets. Likewise, in some embodiments, the malignancy probability is based on assessments of one or more malignancy characteristics for each lesion derived from a combination of structural and functional image data. In one embodiment, the set of structural image data is a set of CT image data and the set of functional image data is a set of PET image data. The one or more lesions may be detected in the structural and/or functional image data by automated routines or by a visual inspection by a clinician or other reviewer.

Abstract: A method and system for calibrating a Time of Flight Positron Emission Tomography (TOF PET) system are provided. The method includes storing acquired scan data from detector pairs. The acquired scan data includes image data and timing information. The method further includes reconstructing images using scan data. The method also includes determining a timing correction for each detector based on intensity distribution histograms of emission sources. The system includes a controller, which is configured to perform the above-mentioned method steps.

Abstract: The invention is directed to a technique for reconstructing PET scan images. According to one embodiment, the invention relates to a method for reconstructing PET scan images. The method comprises: detecting a plurality of coincidence events in a PET scanner; storing data associated with the plurality of coincidence events in a chronological list based on a detection time for each of the plurality of coincidence events; generating correction data based on scatter coincidence events and random coincidence events in the plurality of coincidence events; and reconstructing one or more PET scan images based at least in part on the chronological list of data and the correction data.

Abstract: A method and system for reconstructing an image in a time-of-flight (TOF) positron emission tomography (PET) system is provided. The method includes using a reconstructed image to determine predicted timing information. Timing bias data is updated based on received timing information associated with acquired scan data from a PET system and the predicted timing information. The method further includes reconstructing the image, based on the updated timing bias data.

Abstract: A method and system for controlling a positron emission tomography (PET) system is disclosed. The method includes acquiring image data and time-of-flight information from a PET system during an imaging scan. Further, the method includes performing scatter correction on the image data using the time-of-flight information.

Abstract: Methods and systems for providing scatter correction in a positron emission tomography (PET) system are provided. The method includes determining a look-up table of scatter sinograms during a PET acquisition scan period. The method further includes scatter correcting acquired scan data obtained during the PET acquisition scan 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 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.