Abstract: Systems and method for identifying bone marrow in medical images are provided. A method includes obtaining a three-dimensional (3D) computed tomography (CT) volume data set corresponding to an imaged volume and identifying voxels in the 3D CT volume data set having a Hounsfield Unit (HU) value below a bone threshold. The voxels are identified without using image continuity. The method further includes marking the identified voxels as non-bone voxels, determining definite tissue voxels based on the identified non-bone voxels and expanding a region defined by the definite tissue voxels. The method also includes segmenting the expanded region to identify bone voxels and bone marrow voxels and identifying bone marrow as voxels that are not the bone voxels.

Abstract: According to some embodiments, an emission tomography scanner may acquire emission scan data. One or more anatomical images may be generated using an anatomical imaging system, and the anatomical images may be processed to obtain an initial attenuation image. An emission image and a corrected attenuation image may be jointly reconstructed from the acquired emission scan data, the corrected attenuation image representing a deformation of the initial attenuation image. A final reconstructed emission image may then be calculated based on the reconstructed emission image and/or the corrected attenuation image. The final reconstructed emission image may then be stored in a data storage system and/or displayed on a display system.

Abstract: According to some embodiments, an emission tomography scanner may acquire emission scan data. One or more anatomical images may be generated using an anatomical imaging system, and the anatomical images may be processed to obtain an initial attenuation image. An emission image and a corrected attenuation image may be jointly reconstructed from the acquired emission scan data, the corrected attenuation image representing a deformation of the initial attenuation image. A final reconstructed emission image may then be calculated based on the reconstructed emission image and/or the corrected attenuation image. The final reconstructed emission image may then be stored in a data storage system and/or displayed on a display system.

Abstract: Methods, systems and non-transitory computer readable media for imaging are disclosed. Emission projection data corresponding to a target region of a subject is acquired using an emission tomography system. Additionally, one or more magnetic resonance images of the target region are generated using a magnetic resonance imaging system operatively coupled to the emission tomography system. A partially-determined attenuation map is determined by identifying one or more regions in the partially-determined attenuation map with a designated confidence level based on the magnetic resonance images. Further, a complete attenuation map and/or a complete activity map is reconstructed from the emission projection data using the partially-determined attenuation map as a constraint. One or more images corresponding to the target region are then generated based on the partially-determined attenuation map, the complete attenuation map and/or the complete activity map.

Abstract: Exemplary embodiments of the present disclosure are directed to correcting lung density variations in positron emission tomography (PET) images of a subject using a magnetic resonance (MR) image. A pulmonary vasculature and an outer extent of a lung cavity can be identified in a MR image corresponding to a thoracic region of the subject in response to an intensity associated with pixels in the MR image. The pixels within the outer extent of the lung cavity are classified as corresponding to the pulmonary vasculature or the lung tissue. Exemplary embodiments of the present disclosure can apply attenuation coefficients to a reconstruction of the PET image based on the classification of the pixels within the outer extent of the lung cavity.

Abstract: Embodiments of methods, systems and non-transitory computer readable media for tomographic imaging are presented. 3D TOF projection data is processed to generate corresponding data in a designated format that allows for computationally cheaper image reconstruction than the 3D TOF projection data. Further, one or more preliminary images are reconstructed from the processed data using a particular image reconstruction technique for one or more iterations. To that end, one or more imaging parameters are iteratively varied every one or more iterations. The imaging parameters, for example, include the designated format, the image reconstruction technique and one or more image quality characteristics. One or more intermediate images are reconstructed from the one or more preliminary images using the iteratively varying imaging parameters.

Abstract: Present embodiments relate to the calibration of detectors having one or more arrays of pixelated detectors. According to an embodiment, a method includes detecting optical outputs generated by a plurality of scintillation crystals of a detector with an array of pixelated detectors, generating, with the array of pixelated detectors, respective signals indicative of the optical outputs, generating, from the respective signals, a unique energy spectrum correlated to each of the plurality of scintillation crystals, grouping subsets of the plurality of scintillation crystals into macrocrystals, determining a representative energy spectrum peak for each macrocrystal based on the respective energy spectra of the scintillation crystals in the macrocrystal, comparing a value of the representative energy spectrum peak for each macrocrystal with a target peak value, and adjusting an operating parameter of at least one pixelated detector in the array of pixelated detectors as a result of the comparison.

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: Exemplary embodiments of the present disclosure are directed to correcting lung density variations in positron emission tomography (PET) images of a subject using a magnetic resonance (MR) image. A pulmonary vasculature and an outer extent of a lung cavity can be identified in a MR image corresponding to a thoracic region of the subject in response to an intensity associated with pixels in the MR image. The pixels within the outer extent of the lung cavity are classified as corresponding to the pulmonary vasculature or the lung tissue. Exemplary embodiments of the present disclosure can apply attenuation coefficients to a reconstruction of the PET image based on the classification of the pixels within the outer extent of the lung cavity.

Abstract: An x-ray absorptiometry apparatus and method utilize a radiation source having a beam opening angle of less than or equal to 30 milliradians in at least one dimension, an array of scintillator units to receive radiation from the radiation source with the beam angle after the radiation has passed through a body being imaged and at least one solid-state photomultiplier to receive photons from the array of scintillator units and to produce electrical signal based on the photons. In one implementation, an optical area transmission passage modifier is employed in a dual energy x-ray absorptiometry system. In one implementation, the array of scintillator units are arranged in staggered rows. In yet another implementation, the solid-state photomultiplier includes a plurality of solid-state photomultipliers arranged in rows. In one implementation, a single solid-state photomultiplier receive photons from a plurality of scintillators of the array.

Abstract: A wavelength shifting material is optically coupled to one of a scintillator and a solid-state photomultiplier and transmits photons along and about a straight linear path. The wavelength shifting material enhances photon sensing performance of the solid state photomultiplier.

Abstract: Embodiments of methods, systems and non-transitory computer readable media for tomographic imaging are presented. 3D TOF projection data is processed to generate corresponding data in a designated format that allows for computationally cheaper image reconstruction than the 3D TOF projection data. Further, one or more preliminary images are reconstructed from the processed data using a particular image reconstruction technique for one or more iterations. To that end, one or more imaging parameters are iteratively varied every one or more iterations. The imaging parameters, for example, include the designated format, the image reconstruction technique and one or more image quality characteristics. One or more intermediate images are reconstructed from the one or more preliminary images using the iteratively varying imaging parameters.

Abstract: Methods and systems for multiple scatter estimation in Positron Emission Tomography (PET) are provided. One method includes determining attenuation sinograms and determining a varying convolution kernel as a function of the attenuation sinograms, wherein the kernel varies in amplitude and width over a radial length of a PET imaging system. The method also includes using the varying convolution kernel to estimate multiple PET scatter.

Abstract: Nuclear imaging systems, non-transitory computer readable media and methods for adaptive imaging are presented. Particularly, the present method includes acquiring preliminary projection data by scanning each of one or more views of a subject for a determined preliminary scan interval. Further, a region of interest of the subject is identified. The preliminary projection data is then used to perform a constrained optimization of a rapidly computable image quality metric for determining an acquisition protocol that improves the image quality metric at the identified region of interest. Particularly, the determined acquisition protocol is used to acquire target projection data corresponding to at least the identified region of interest. Further, an image of at least the identified region of interest is reconstructed using the target projection data, the preliminary projection data, or a combination thereof.

Abstract: Present embodiments relate to the calibration of detectors having one or more arrays of pixelated detectors. According to an embodiment, a method includes detecting optical outputs generated by a plurality of scintillation crystals of a detector with an array of pixelated detectors, generating, with the array of pixelated detectors, respective signals indicative of the optical outputs, generating, from the respective signals, a unique energy spectrum correlated to each of the plurality of scintillation crystals, grouping subsets of the plurality of scintillation crystals into macrocrystals, determining a representative energy spectrum peak for each macrocrystal based on the respective energy spectra of the scintillation crystals in the macrocrystal, comparing a value of the representative energy spectrum peak for each macrocrystal with a target peak value, and adjusting an operating parameter of at least one pixelated detector in the array of pixelated detectors as a result of the comparison.

Abstract: An imaging method comprises reconstructing gated emission tomography images for a region of interest, adjusting a mismatch between the gated emission tomography images and a computed tomography image of the region of interest, registering the gated emission tomography images, and combining the registered gated emission tomography images to generate motion corrected images.

Abstract: Nuclear imaging systems, non-transitory computer readable media and methods for tomographic imaging are presented. Projection data is acquired by scanning one or more views of a subject for a designated scan interval less than a total scan interval. A first image of a target region of interest (ROI) is reconstructed using projection data acquired over a first fraction of the designated scan interval. A second target ROI image is reconstructed using at least a subset of projection data acquired over the first and/or a second fraction. A change in an image quality characteristic over the first and the second fractions is determined by determining one or more differences between the first and the second images. A value of an imaging parameter is estimated based on the change to acquire projection data for generating a target ROI image having at least a predetermined level of the image quality characteristic.

Abstract: Nuclear imaging systems, non-transitory computer readable media and methods for adaptive imaging are presented. Particularly, the present method includes acquiring preliminary projection data by scanning each of one or more views of a subject for a determined preliminary scan interval. Further, a region of interest of the subject is identified. The preliminary projection data is then used to perform a constrained optimization of a rapidly computable image quality metric for determining an acquisition protocol that improves the image quality metric at the identified region of interest. Particularly, the determined acquisition protocol is used to acquire target projection data corresponding to at least the identified region of interest. Further, an image of at least the identified region of interest is reconstructed using the target projection data, the preliminary projection data, or a combination thereof.

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 multiple scatter estimation in Positron Emission Tomography (PET) are provided. One method includes determining attenuation sinograms and determining a varying convolution kernel as a function of the attenuation sinograms, wherein the kernel varies in amplitude and width over a radial length of a PET imaging system. The method also includes using the varying convolution kernel to estimate multiple PET scatter.