Abstract: When compensating for truncated patient scan data acquired by a multi-modal PET/CT or PET/MR imaging system (14, 16), such as occurs when a patient is larger than a field of view for an anatomical imaging device, a segmented contour of a non-attenuation-corrected (NAC) PET image is used to identify a contour of the truncated region. An appropriate tissue type is used to fill in truncated regions of a truncated CT or MR image for the attenuation map. The corrected attenuation map is then used to generate an attenuation-corrected PET image of the patient or a region of interest. Alternatively, the system can be employed in PET/CT or PET/MR imaging scenarios where two modalities are performed sequentially (e.g., not simultaneously), and thus the contour derived from the PET scan can be compared to the CT or MR image to infer potential subject motion between the PET and CT or MR scans.

Abstract: An ultrasonic probe suitable for reducing reflected waves returning from a rear surface part to a transducer side, and an ultrasonic diagnostic apparatus. Ultrasonic probe 1 comprises transducer 10 transmitting and receiving ultrasonic waves to and from a subject, a backing material 12 disposed on the rear side of the transducer 10, and heat dissipating block 14 stacked on the backside of the backing material 12. At least one of the backing material 12 and heat-dissipating block 14 comprises void 16 therein. A sound absorbing material 18 is desirably filled in void 16.

Abstract: Methods, systems and apparatuses for processing data associated with nuclear medical imaging techniques are provided. Data is ordered in LUT's and memory structures. Articles of manufacture are provided for causing computers to carry out aspects of the invention. Data elements are ordered into a plurality of ordered data groups according to a spatial index order, and fetched and processed in the spatial index order. The data elements include sensitivity matrix elements, PET annihilation event data, and system and image matrix elements, the data grouped in orders corresponding to their processing. In one aspect geometric symmetry of a PET scanner FOV is used in ordering the data and processing. In one aspect a system matrix LUT comprises total number of system matrix elements equal to a total number of image matrix elements divided by a total number of possible third index values.

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 and apparatus for performing an iterative image reconstruction uses two or more processors (130). The reconstruction task is distributed among the various processors (130). In one embodiment, the projection space data (300) is distributed among the processors (130). In another embodiment, the object space (200) is distributed among the processors (130).

Abstract: A method and apparatus are provided for reconstructing list mode data acquired during a positron emission tomography scan of an object, the data including information indicative of a plurality of detected positron annihilation events. Detected events occurring in a region of interest are identified; the identified events are reconstructed using an iterative reconstruction technique which includes a ray tracing operation to generate volumetric data indicative of the region of interest, wherein the ray tracing operation traces only image matrix elements located in the region of interest; and a human readable image indicative of the volumetric data is generated. In another aspect an image mask and a projection mask are defined correlating to the region of interest; image matrix elements located in the region of interest are determined by applying the image mask; and detected events occurring in a region of interest are identified by applying the projection mask.

Abstract: A method and system for use in positron emission tomography, wherein a first processor element (234) is configured to reconstruct a plurality of positron annihilation events detected during a positron emission tomography scan using a list-based reconstruction technique to generate first volumetric data. A second reconstructor (226) is configured to reconstruct the plurality of events using a second reconstruction technique to generate second volumetric data for determining an error correction (228), the error correction applied to the first volumetric data to generate corrected volumetric data for generating a human-readable image (234). In one embodiment a multiplicative error correction is performed on the plurality of events, the first processor element (234) reconstructing the corrected plurality of events; and the second volumetric data error correction comprises an additive error correction.

Abstract: An ultrasonic probe suitable for reducing reflected waves returning from a rear surface part to a transducer side, and an ultrasonic diagnostic apparatus. Ultrasonic probe 1 comprises transducer 10 transmitting and receiving ultrasonic waves to and from a subject, a backing material 12 disposed on the rear side of the transducer 10, and heat dissipating block 14 stacked on the backside of the backing material 12. At least one of the backing material 12 and heat-dissipating block 14 comprises void 16 therein. A sound absorbing material 18 is desirably filled in void 16.

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 and apparatus for performing an iterative image reconstruction uses two or more processors (130). The reconstruction task is distributed among the various processors (130). In one embodiment, the projection space data (300) is distributed among the processors (130). In another embodiment, the object space (200) is distributed among the processors (130).