Abstract: For count loss correction, the capability of the discriminator, measured periodically, to detect an event is identified. Rather than inserting an actual event or a signal emulating an actual event for discrimination, the capability to discriminate is tested by a virtual injection. The count loss may be directly measured without causing extra actual discrimination by the discriminator. Direct measurement with virtual testing may avoid loss of accuracy due to time and use-case variation.

Abstract: A method comprises: detecting a plurality of radiation events using a plurality of radiation detectors; determining a fraction of the plurality of radiation events, such that a coincidence circuit has sufficient capacity to process each radiation event in the fraction of the plurality of radiation events; counting the determined fraction of the plurality of radiation events using the coincidence circuit, and excluding a remainder of the plurality of radiation events from the counting; and performing positron emission tomography (PET) processing on each radiation event in the fraction of the plurality of radiation events.

Abstract: In a method and a computer for identifying a group of persons, from a number of persons, to whom at least one contrast agent has been applied during an examination which was carried out in an imaging system with which medical images of each of the number of persons were produced, existing examination data provided for each of the number of persons are used to determine to which of those persons the at least one contrast agent was applied. The persons to whom at least one contrast agent was applied during the examination are identified as a group of persons. For each person in the group, person-specific contrast agent data are determined that include at least identification information identifying the person to whom the at least one contrast agent was applied, and contrast agent information identifying the fact that the at least one contrast agent was applied. A designation of each person in the group of persons is stored with that person's corresponding person-specific contrast agent data in a register.

Abstract: Classification preprocessing is provided for medical ultrasound shear wave imaging. In response to stress, the displacement at one or more locations in a patient is measured. The displacement over time is a curve representing a shift in location. One or more characteristics of the curve, such as signal-to-noise ratio and maximum displacement, are used to classify the location. The location is classified as fluid or fluid tissue, solid tissue, or non-determinative. Subsequent shear imaging may provide shear information for locations of solid tissue and not at other locations.

Abstract: Disclosed herein is a method for estimating count loss in a gamma camera comprising injecting a synthetic pulse at a given rate into a data stream emanating from a photo detector; integrating the synthetic pulse into the data stream to form an integrated data stream; determining a number of synthetic pulses from the data stream that pass onto a final image; and determining the count loss from the Equation (2) Percent ? ? Count ? ? Loss = ( Number ? ? of ? ? pulses ? ? introduced - Number ? ? of ? ? pulses ? ? detected ) × 100 Number ? ? of ? ? pulses ? ? ? introduced .

Abstract: To accurately generate the three-dimensional ultrasound data and/or determine the position of the ultrasound scan relative to pre-operative data, a tracking sensor is releasably connected with the ultrasound probe. The connection positions the tracking sensor near a distal end of the probe for insertion into the patient. A needle guide may be similarly releasably connected with the probe and, at least in part, inserted into the patient.

Abstract: Computerized characterization of cardiac wall motion is provided. Quantities for cardiac wall motion are determined from a four-dimensional (i.e., 3D+time) sequence of ultrasound data. A processor automatically processes the volume data to locate the cardiac wall through the sequence and calculate the quantity from the cardiac wall position or motion. Various machine learning is used for locating and tracking the cardiac wall, such as using a motion prior learned from training data for initially locating the cardiac wall and the motion prior, speckle tracking, boundary detection, and mass conservation cues for tracking with another machine learned classifier. Where the sequence extends over multiple cycles, the cycles are automatically divided for independent tracking of the cardiac wall. The cardiac wall from one cycle may be used to propagate to another cycle for initializing the tracking. Independent tracking in each cycle may reduce or avoid inaccuracies due to drift.

Abstract: A set of first modality data is provided to an intra-reconstruction motion correction method. The set of first modality data includes a plurality of views. A set of second modality data is provided to the method. A motion estimate is generated for each of the plurality of views in the set of first modality data by registering the set of first modality data with the set of second modality data. A motion corrected model of the set of first modality data is generated by a forward projection including the motion estimate.

Abstract: A set of set of first modality data is received including at least one view comprising a plurality of gates. The set of first modality data is received from a first imaging modality of an imaging system. A set of second modality data is received from a second imaging modality of the imaging system. A motion corrected model of the set of first modality data is generated by forward projecting the set of first modality data including a motion estimate. An update factor for each of the plurality of views is generated by comparing at least one of the plurality of gates to the motion corrected model. The motion corrected model is updated by the update factor to generate a motion corrected image.

Abstract: Projection data are acquired by one or more gamma detectors of a medical imaging system. The counts for each projection are binned into time bins to provide respective frames. Using a computer processor, a respective weight factor is computed for each pair of input points among a plurality of input points associated with respective time bins, each input point being an M-dimensional representation of the frame corresponding to the associated time bin for one of the projections. Each weight factor is inversely proportional to a distance computed between the corresponding pair of input points according to an adaptive distance measure that is dependent on the projection data corresponding to said one projection. An N-dimensional surrogate respiratory signal (N<M) is generated based on an optimization of a nonlinear objective function using the weight factors, wherein the surrogate respiratory signal is indicative of patient respiratory activity.

Abstract: Shear waves are detected with ultrasound. The detection of the shear wave is constrained using prior measurements in a more controlled environment (e.g., less noise). For example, shear waves measured in a phantom are used to constrain the detection of shear waves in a patient to avoid false positive detections.

Abstract: A regurgitant orifice of a valve is detected. The valve is detected from ultrasound data. An anatomical model of the valve is fit to the ultrasound data. This anatomical model may be used in various ways to assist in valvular assessment. The model may define anatomical locations about which data is sampled for quantification. The model may assist in detection of the regurgitant orifice using both B-mode and color Doppler flow data with visualization without the jet. Segmentation of a regurgitant jet for the orifice may be constrained by the model. Dynamic information may be determined based on the modeling of the valve over time.

Abstract: A radiation detector comprises a first scintillator having a first peak wavelength and a second scintillator positioned on the first scintillator. The second scintillator has a second peak wavelength different from the first peak wavelength. A plurality of photon detectors are provided. The first scintillator is positioned over and contacts each of the plurality of photon detectors. The plurality of photon detectors include first detectors and second detectors. The second detectors differ from the first detectors in doping profile, pn junction depth, or front-versus-backside illumination geometry. The first detectors are more sensitive to the first peak wavelength than the second peak wavelength. The second detectors are more sensitive to the second peak wavelength than the first detectors.

Abstract: For dose calibration in functional imaging, an amount of bias in a dose calibrator measurement of activity is determined using a spectroscopic detector. The bias may then be used to correct dose values for the same isotope used to determine a factory-based sensitivity of the functional imaging system. When local functional imaging systems are calibrated, any difference in sensitivity from the factory measured sensitivity may be due to local dose calibrator bias, so the difference in sensitivity is used to determine a local correction.

Abstract: Systems and methods for generating corrected emission tomography images are provided. A method includes obtaining a reconstructed image based on emission tomography data of a head of a patient and defining a boundary region in the reconstructed image estimating a position of a skull of the patient in the reconstructed image. The method also includes generating a map of attenuation coefficient values for the reconstructed image based on the boundary region. The reconstructed image can then be adjusted based on the map. In the method, the attenuation coefficient values within the boundary region are selected to correspond to an attenuation coefficient value for bone and the attenuation coefficient values for the portion of the image surrounded by the boundary region are selected to correspond to an attenuation value for tissue.

Abstract: A method of growing a rare-earth oxyorthosilicate crystal, and crystals grown using the method are disclosed. The method includes preparing a melt by melting a first substance including at least one first rare-earth element and providing an atmosphere that includes an inert gas and a gas including oxygen.

Abstract: Apparatuses, computer-readable mediums, and methods are provided. In one embodiment, a positron emission tomography (“PET”) detector array is provided which includes a plurality of crystal elements arranged in a two-dimensional checkerboard configuration. In addition, there are empty spaces in the checkerboard configuration. In various embodiments, the empty spaces are filled with passive shielding, transmission source assemblies, biopsy instruments, surgical instruments, and/or electromagnetic sensors. In various embodiments, the crystal elements and the transmission source assemblies simultaneously perform emission/transmission acquisitions.

Abstract: A patient support for a nuclear medicine imaging system has a base a joint and a chair. The chair can pivot or rotate about the joint. This allows the patient chair to assume a patient loading and a patient imaging position with respect to the detectors of the imaging system. Furthermore, the chair is adjustable to improve the ability of a patient region to be covered by the filed of view of the detectors.

Abstract: Projection data are acquired for a portion of the body of a patient at multiple views using one or more detectors, the projection data including multiple two dimensional (2D) projections. A 3D image is initialized. For each view among the plurality of views, the 3D image is transformed using a view transformation corresponding to said view to generate an initial transformed image corresponding to said view, and multiple iterations of an MLEM process are performed based on at least the initial transformed image and the projection data. The MLEM process is initialized with the initial transformed image. The 3D image is updated based on an output of the MLEM process.

Abstract: Reconstruction quality is assessed in medical imaging. An amount of local non-uniformity in a distribution of a statistical measure (e.g., MCDF) is determined. The amount indicates a level of reconstruction quality. A more easily understood amount rather than a rendering of MCDF and/or the amount being a function of local artifacts aids a radiologist in recognizing reconstruction quality and determining whether different reconstruction is warranted.