Abstract: A method for producing an attenuation-corrected time-gated PET image comprising includes obtaining a baseline MR image and a cine MR image of a structure; registering the baseline MR image to the cine MR image to create an image transform; and generating a corresponding cine ACF matrix using the image transform, and time-correlating the ACF matrix to a time-gated PET data set to produce an attenuation-corrected time-gated PET image.

Abstract: Exemplary embodiments of the present disclosure are directed to scheduling positron emission tomography (PET) scans for a combined PET-MRI scanner based on an acquisition of MR scout images of a subject. An anatomy and orientation of the subject can be determined based on the MR scout images and the schedule for acquiring PET scans of the subject can be determined from the anatomy of the subject. The schedule generated using exemplary embodiments of the present disclosure can specify a sequence of bed positions, scan durations at each bed position, and whether respiratory gating will be used at one or more of the bed positions.

Abstract: A method for producing an attenuation-corrected time-gated PET image comprising includes obtaining a baseline MR image and a cine MR image of a structure; registering the baseline MR image to the cine MR image to create an image transform; and generating a corresponding cine ACF matrix using the image transform, and time-correlating the ACF matrix to a time-gated PET data set to produce an attenuation-corrected time-gated PET image.

Abstract: A method for attenuation correction of a plurality of time-gated PET images of a moving structure includes establishing an ACF matrix, based on a baseline MR image of the structure; developing a plurality of image transforms, each of the image transforms registering the baseline MR image to a respective cine MR image of the moving structure; applying each of the image transforms to the ACF matrix to generate a corresponding cine ACF matrix; time-correlating each of the cine MR images, and its corresponding cine ACF matrix, to one of the plurality of time-gated PET data sets; and producing from each of the time-gated PET data sets an attenuation-corrected time-gated PET image.

Abstract: A method for attenuation correction of a plurality of time-gated PET images of a moving structure includes establishing an ACF matrix, based on a baseline MR image of the structure; developing a plurality of image transforms, each of the image transforms registering the baseline MR image to a respective cine MR image of the moving structure; applying each of the image transforms to the ACF matrix to generate a corresponding cine ACF matrix; time-correlating each of the cine MR images, and its corresponding cine ACF matrix, to one of the plurality of time-gated PET data sets; and producing from each of the time-gated PET data sets an attenuation-corrected time-gated PET image.

Abstract: A method for generating a Positron Emission Tomography (PET) image includes defining a scan window having a predetermined length along an examination axis of a PET imaging system, the scan window corresponding to a region of interest to be continuously scanned by the PET imaging system, defining at least two data bins corresponding to two separate scan regions within the scan window, defining a transition region that overlaps a portion of each of the separate scan regions within the scan window, the transition region having a width that is shorter than a length of the scan window, binning emission data acquired within the transition region into the two data bins, binning emission data acquired from outside the transition region into one of the two data bins, and reconstructing an image using the emission data in the two data bins.

Abstract: A method for generating a Positron Emission Tomography (PET) image includes defining a scan window having a predetermined length along an examination axis of a PET imaging system, the scan window corresponding to a region of interest to be continuously scanned by the PET imaging system, defining at least two data bins corresponding to two separate scan regions within the scan window, defining a transition region that overlaps a portion of each of the separate scan regions within the scan window, the transition region having a width that is shorter than a length of the scan window, binning emission data acquired within the transition region into the two data bins, binning emission data acquired from outside the transition region into one of the two data bins, and reconstructing an image using the emission data in the two data bins.

Abstract: Exemplary embodiments of the present disclosure are directed to scheduling positron emission tomography (PET) scans for a combined PET-MRI scanner based on an acquisition of MR scout images of a subject. An anatomy and orientation of the subject can be determined based on the MR scout images and the schedule for acquiring PET scans of the subject can be determined from the anatomy of the subject. The schedule generated using exemplary embodiments of the present disclosure can specify a sequence of bed positions, scan durations at each bed position, and whether respiratory gating will be used at one or more of the bed positions.

Abstract: A method and system for reconstructing an image of an object. The method includes acquiring an image dataset of an object of interest, identifying valid data and invalid data in the image dataset, determining a time period that includes the valid data, weighting the valid data based on the determined time period, and reconstructing an image of the object using the weighted valid data.

Abstract: Apparatus and methods for geometric calibration of positron emission tomography (PET) systems are provided. One method includes obtaining scan data for a uniform phantom and generating reference images based on the scan data for the uniform phantom. The method further includes reconstructing images of the uniform phantom using a PET imaging system and determining a geometric calibration for the PET imaging system based on a comparison of the reconstructed images and the reference images.

Abstract: Apparatus and methods for determining a boundary of an object for positron emission tomography (PET) scatter correction are provided. One method includes obtaining positron emission tomography (PET) data and computed tomography (CT) data for an object. The PET data and CT data is acquired from an imaging system. The method further includes determining a PET data boundary of the object based on the PET data and determining a CT data boundary of the object based on the CT data. The method further includes determining a combined boundary for PET scatter correction. The combined boundary encompasses the PET data boundary and the CT data boundary.

Abstract: A method for estimating randoms in PET imaging data includes acquiring imaging data that includes a plurality of singles and a plurality of randoms, where the randoms exhibit a non-exponential decay, generating a randoms correction estimate based on the non-exponential decay, and applying the randoms correction estimate to the imaging data to generate corrected imaging data. The method further includes generating an image using the corrected image data. An imaging system and computer readable medium programmed to estimate randoms is also provided.

Abstract: A method and apparatus are provided for correcting primary and secondary emission data. The method includes obtaining an emission data set having primary and secondary emission data representative of primary and secondary emission particles emitting from a region of interest and applying a scatter correction model to the emission data set to derive an estimated scatter vector. The method also includes comparing the emission data set to the estimated scatter vector to identify an amount of secondary emission data in the emission data set and correcting the emission data set based on the amount of secondary emission data identified in the comparing operation.

Abstract: Apparatus and methods for determining a boundary of an object for positron emission tomography (PET) scatter correction are provided. One method includes obtaining positron emission tomography (PET) data and computed tomography (CT) data for an object. The PET data and CT data is acquired from an imaging system. The method further includes determining a PET data boundary of the object based on the PET data and determining a CT data boundary of the object based on the CT data. The method further includes determining a combined boundary for PET scatter correction. The combined boundary encompasses the PET data boundary and the CT data boundary.

Abstract: Methods and systems for correcting image scatter are provided. The method includes generating an estimate of a detector activity, determining a probability that a scatter event has been counted as a true event using the estimate of a detector activity; generating a scatter correction estimate based on the determined probability, and applying the scatter correction estimate to an emission data set to generate an image of an object.

Abstract: A method and system for reconstructing an image of an object. The method includes acquiring an image dataset of an object of interest, identifying valid data and invalid data in the image dataset, determining a time period that includes the valid data, weighting the valid data based on the determined time period, and reconstructing an image of the object using the weighted valid data.

Abstract: Apparatus and methods for geometric calibration of positron emission tomography (PET) systems are provided. One method includes obtaining scan data for a uniform phantom and generating reference images based on the scan data for the uniform phantom. The method further includes reconstructing images of the uniform phantom using a PET imaging system and determining a geometric calibration for the PET imaging system based on a comparison of the reconstructed images and the reference images.

Abstract: A method for retrospectively correcting data prior to image reconstruction using an imaging system, wherein the method includes acquiring a first sinogram of a first slice of an object at a first axial field of view and a second sinogram of the first slice of the object at a second axial field of view different than the first axial field of view, determining at least one boundary of the object in the first sinogram and the second sinogram at the first slice, measuring a shift between the first sinogram and the second sinogram using the determined boundaries, and generating a corrected image using the measured shift.

Abstract: A method and apparatus are provided for correcting primary and secondary emission data. The method includes obtaining an emission data set having primary and secondary emission data representative of primary and secondary emission particles emitting from a region of interest and applying a scatter correction model to the emission data set to derive an estimated scatter vector. The method also includes comparing the emission data set to the estimated scatter vector to identify an amount of secondary emission data in the emission data set and correcting the emission data set based on the amount of secondary emission data identified in the comparing operation.

Abstract: Methods for performing image reconstruction that include deriving background projection data for an area outside a targeted field of view of a tomographic image, and reconstructing the tomographic image of the targeted field of view, wherein the background projection data is used in the reconstruction. Methods for selecting a reconstruction methodology that include determining a number of pixels in a reconstructed image for a first reconstruction methodology, determining a number of pixels in a reconstructed image for a second reconstruction methodology, comparing the number of pixels for the first reconstruction methodology and the number of pixels for the second reconstruction methodology, and selecting the reconstruction methodology for image reconstruction based on the comparison of the number of pixels. Imaging systems implementing these methods are also provided.