Abstract: A method includes obtaining a combined data set that includes first and second imaging data sets. The first and second imaging data sets correspond to different imaging modalities. The method further includes determining a metric indicative of an alignment between the first and second imaging data sets in the combined data set. The method further includes presenting the metric in a human readable format.

Abstract: A medical imaging system includes a view transformation component (210) and a segment combiner (212). The transformation component (210) transforms projection data in each view of a plurality of individual segments, which each includes at least one view. The transformed projection data for substantially similar views across the plurality of individual segments have a common radius of rotation. The segment combiner (212) combines the transformed projection data to produce a single data set that includes the transformed projection data for each of the views of each of the plurality of individual segments.

Abstract: A nuclear imaging chain (100) includes a molecular agent (102), an acquisition system (104), a reconstruction system (106), a detection system (108), and a display system (110). The various components of the imaging chain are optimized according to desired optimization criteria. The optimized characteristics of the imaging chain (100) may include one or more an agent characteristic, an acquisition characteristic (127), a reconstruction characteristic (143), a detection characteristic (159), and a display characteristic.

Abstract: An imaging system (10) comprises at least one radiation detector (20) disposed adjacent a subject receiving aperture (18) to detect radiation from a subject, receive the radiation and generate measured data. An image processor (38) iteratively reconstructs the detected radiation into image representations, in each reconstruction iteration the image processor (38) applies noise reduction algorithms to at least a difference between the measured data and a portion of a previous iteration image representation.

Abstract: A physiological parameter monitor (44) monitors a cyclic physiological parameter and generates a cyclic parameter phase indicative signal. A radiation system (8) is disposed adjacent an examination region (18, 28) to generate transmission radiation data and emission radiation data. First and second sorting devices (48, 74) sort corresponding transmission and emission radiation data into transmission radiation data sets (50) and emission radiation data sets (78) corresponding to each of a plurality of the cyclic parameter phases. A data processor (60) reconstructs attenuation maps (62) from the transmission data for each of the plurality of cyclic parameter phases. An image processor (80) corrects the emission radiation data of each cyclic parameter phase with the attenuation map (62) of the same cyclic parameter phase and reconstructs the attenuation corrected emission data sets into an image representation for each cyclic parameter phase.

Abstract: A medical imaging system (10) includes at least one radiation detection head (16) disposed adjacent a subject receiving aperture (18) to detect radiation from a subject. The detected radiation is reconstructed into at least one initial 2D projection image (?). Resolution in each initial 2D image (?) is restored by using the extended iterative constrained deconvolution algorithm by incorporating different estimates of the system response function which estimates correspond to different distances between the detection head and the origins of the detected radiation. Measured response functions are used to restore a series of images. The optimal image is determined by automatic searching with the figure of merit, by user's observation, or by using blind deconvolution for a concurrent estimating of the system response function and updating the original image.

Abstract: In a method for generating an attenuation map (30), image elements of a reconstructed tomographic image (24) are segmented into at least first, second, and third classes (50, 52, 54). Each image element of the first class (50) is transformed using a first image element value-dependent attenuation transform (60). Each image element of the second class (52) is transformed using a second image element value-dependent attenuation transform (62) different from the first image element value-dependent attenuation transform. Each image element of the third class (54) is transformed using a third image element value-dependent attenuation transform (64) different from both the first and second image element value-dependent attenuation transforms.

Abstract: Medical images are collected in a plurality of cardiac and respiratory phases. The images are transformed into a series of respiratory compensated images with the plurality of cardiac phases, but all at a common respiration phase. The series of respiratory compensated images are transformed into one image at a selected cardiac phase and the common respiration phase. In some embodiments, a database of gated transform matrices is generated. The database may be based on specific patient information or on information generated from a pool of patients. The database may account for respiratory motion, cardiac contractile motion, other physiological motion, or combinations thereof. For a current image to be motion corrected, the transformation matrices collected in the database are used to estimate a current set of transformation matrices accounting for the motion in the current image, and a motion-compensated image is generated based on the current set of transform matrices.

Abstract: In an imaging method, estimated data is iteratively projected and backprojected. The iterative projecting and backprojecting includes projecting or backprojecting the estimated data along parallel paths each employing energy-dependent parameters appropriate for a different energy. During each iteration, the estimated data is adjusted based on comparison of the estimated data with measured data.

Abstract: A method for non-rigid registration and fusion of images with physiological modeled organ motions resulting from respiratory motion and cardiac motion that are mathematically modeled with physiological constraints. A method of combining images comprises the steps of obtaining a first image dataset (24) of a region of interest of a subject and obtaining a second image dataset (34) of the region of interest of the subject. Next, a general model of physiological motion for the region of interest is provided (142). The general model of physiological motion is adapted with data derived from the first image data set (140) to provide a subject specific physiological model (154). The subject specific physiological model is applied (172) to the second image dataset (150) to provide a combined image (122).

Abstract: A diagnostic imaging system (20) comprising a computer workstation (26) for controlling the imaging system, interfacing with an operator and generating images. A coordinate system (100) is in data communication with the computer workstation. The coordinate system (100) is adapted to describe relative position of components in the diagnostic imaging system (20). A subject support (30) is describable within the coordinate system and an X-ray sub-system (22) is positionable around the subject support (30). Position sensors (44a) are operatively connected to the x-ray sub-system (22) and they provide signals to the workstation (26) indicative of the position of components of the x-ray sub-system (22) within the space represented by the coordinate system. A nuclear camera sub-system (24) is positionable around the subject support (30).

Abstract: A diagnostic imaging system (20) comprising a computer workstation (26) for controlling the imaging system, interfacing with an operator and generating images. A coordinate system (100) is in data communication with the computer workstation. The coordinate system (100) is adapted to describe relative position of components in the diagnostic imaging system (20). A subject support (30) is describable within the coordinate system and an X-ray sub-system (22) is positionable around the subject support (30). Position sensors (44a) are operatively connected to the x-ray sub-system (22) and they provide signals to the workstation (26) indicative of the position of components of the x-ray sub-system (22) within the space represented by the coordinate system. A nuclear camera sub-system (24) is positionable around the subject support (30).

Abstract: A method for non-rigid registration and fusion of images with physiological modeled organ motions resulting from respiratory motion and cardiac motion that are mathematically modeled with physiological constraints. A method of combining images comprises the steps of obtaining a first image dataset (24) of a region of interest of a subject and obtaining a second image dataset (34) of the region of interest of the subject. Next, a general model of physiological motion for the region of interest is provided (142). The general model of physiological motion is adapted with data derived from the first image data set (140) to provide a subject specific physiological model (154). The subject specific physiological model is applied (172) to the second image dataset (150) to provide a combined image (122).

Abstract: A gamma camera system and method are described which use multiple point sources to detect inaccuracies in detector translational and rotational alignment. In practice of the method of the preferred embodiment, three capillary tubes, each containing a drop of an isotope, are located in different planes and locations with respect to the axis of rotation of the detectors. A SPECT acquisition is performed and the point source projection data is processed to calculate the point source coordinates, from which center-of-rotation correction factors may be calculated. These correction factors are applied by mechanical and software adjustments to the gantry and acquisition systems of the camera to correct for both translational and rotational inaccuracies.

Abstract: A gamma camera system and method are described which use multiple point sources to detect inaccuracies in detector translational and rotational alignment. In practice of the method of the preferred embodiment, three capillary tubes, each containing a drop of an isotope, are located in different planes and locations with respect to the axis of rotation of the detectors. A SPECT acquisition is performed and the point source projection data is processed to calculate the point source coordinates, from which center-of-rotation correction factors may be calculated. These correction factors are applied by mechanical and software adjustments to the gantry and acquisition systems of the camera to correct for both translational and rotational inaccuracies.

Abstract: A method of correcting for deadtime and for emission contamination of a transmission scan in a nuclear camera system is provided. The transmission scan is used to correct positron emission tomography (PET) images for attenuation. The camera system includes two detectors and two corresponding single-photon point sources that are collimated to produce fanbeam illumination profiles. A transmission detection window and an emission contamination detection window is defined on each detector. Radiation from each source is scanned axially across the field of view of the corresponding detector in synchronization with the corresponding transmission detection window to acquire transmission projection data. The emission contamination detection windows are also scanned axially concurrently with, but offset from, the transmission detection windows to acquire emission data.

Abstract: A nuclear medicine imaging system includes the capability to correct for the deadtime, including the capability to correct for spatial variations in deadtime across the imaging surface of a detector. The imaging system includes one or more radiation detectors, each using a large, monolithic scintillation crystal. Each detector has deadtime associated with it. A given detector is used to acquire an energy profile of a patient based on emission radiation. The detector includes a number of timing channels. The energy profile is used to select a zone influence map indicating the extent of spatial overlap in response between the various timing channels. Emission data of the patient is then acquired during an emission scan. During acquisition of the emission data, a rate meter assigned to each timing channel samples the number of counts associated with each timing channel to acquire deadtime data.

Abstract: A transmission pre-scan of a patient is used in a nuclear medicine imaging system to determine the duration of a subsequent transmission scan of the patient. The transmission scan is for acquiring an attenuation map of the patient to correct emission data of the patient for non-uniform attenuation. As a result, the patient's exposure to radiation during the transmission scan is not excessive, yet transmission image quality is maintained. A radiation transmission source and a radiation detector are operated to perform the transmission pre-scan of the object, during which the transmission source remains in a fixed position. Downscatter correction is applied to correct the transmission pre-scan data for emission contamination. Count values from the pre-scan data are integrated axially.

Abstract: A method of correcting for deadtime and for emission contamination of a transmission scan in a nuclear camera system is provided. The transmission scan is used to correct positron emission tomography (PET) images for attenuation. The camera system includes two detectors and two corresponding single-photon point sources that are collimated to produce fanbeam illumination profiles. A transmission detection window and an emission contamination detection window is defined on each detector. Radiation from each source is scanned axially across the field of view of the corresponding detector in synchronization with the corresponding transmission detection window to acquire transmission projection data. The emission contamination detection windows are also scanned axially concurrently with, but offset from, the transmission detection windows to acquire emission data.

Abstract: A method and apparatus for correcting for random coincidences in a gamma camera imaging system are provided, based on the distribution of the object to be imaged as well as the measured singles and coincidence rates. Gamma radiation emitted from the object is detected for multiple projection angles, including detection of a plurality of coincidence events, to generate an object profile. The singles rate and the coincidence rate are also measured for each of the projection angles. A randoms distribution representing random coincidences in the detected coincidence events is then determined, including computing a randoms profile as the convolution of the object profile and a Gaussian function.