摘要:
A digital photosensor that includes a photomultiplier tube (PMT) including a power distribution circuit, the PMT outputting an analog signal in response to received light; an analog-to-digital converter (ADC) to receive the analog signal and to generate a digital signal; and a non-transitory memory storing manufacturing parameters of the PMT and operational parameters of the PMT, the operational parameters being calculated by a parameter calculation unit during operation of the PMT, wherein the PMT, the ADC, and the memory are integrated into a single housing.
摘要:
A positron emission tomography scanner system that includes detector modules arranged adjacent to one another to form a cylindrical detector ring. Each of the detector modules includes an array of scintillation crystal elements, a plurality of photosensors arranged to cover the array of crystal elements and configured to receive light emitted from the array of crystal elements, and a fiber optics plate arranged between the array of scintillation crystal elements and the plurality of photosensors, the fiber optics plate including a plurality of fibers configured to guide the light emitted from the scintillation crystal to the plurality of photosensors.
摘要:
When employing hygroscopic scintillation crystals (32) in a nuclear detector (e.g., PET or SPECT), Silicon photo-multiplier (SiPM) sensors (34) are coupled to each scintillation crystal (32) to improve scintillation event detection and reduce scatter. The crystals (32) and sensors (34) are hermetically sealed in a detector housing (50) using a sealant layer (51). Electrical contacts (60) from each sensor (34) extend through the sealant layer (51) or are bused together such that the bus extends through the sealant layer (51). In this manner, hygroscopic scintillation crystals (e.g., LaBr, NaI, etc.) are protected from humidity and light scatter is reduced by direct coupling of the sensors (34) and crystals (32).
摘要:
An imaging system comprises: a ring of positron emission tomography (PET) detectors; a PET housing at least partially surrounding the ring of PET detectors and defining a patient aperture of at least 80 cm; a coincidence detection processor or circuitry configured to identify substantially simultaneous 511 keV radiation detection events corresponding to electron-positron annihilation events; and a PET reconstruction processor configured to reconstruct into a PET image the identified substantially simultaneous 511 keV radiation detection events based on lines of response defined by the substantially simultaneous 511 keV radiation detection events. Radiation planning utilizing such an imaging system comprises: acquiring PET imaging data for a human subject arranged in a radiation therapy position requiring a patient aperture of at least about 80 cm; reconstructing said imaging data into a PET image encompassing an anatomical region to undergo radiation therapy; and generating a radiation therapy plan based on at least the PET image.
摘要:
Disclosed is a triple-sensor motion detector for illuminating the approach to a display case or other object. The triple-sensor motion detector provides a field of detection that spans the front width of the case, yet does not include the areas along the sides of the case. The detector reduces inadvertent triggering of the illumination by persons approaching the side of the case or approaching another case on the other side of an aisle.
摘要:
A PET system includes an improved image reconstruction algorithm based on an improved modeling of the point-spread function. PET time of flight data is used to obtain a mean emitting point and a time of flight probability function. This information is then used to model the point-spread function. The time of flight probability function and the detector response function are used to define a probability volume for a given line of response, which is then used in the reconstruction of the image.
摘要:
A nuclear camera (10) includes four or more gamma detectors (20, 20′, 20″, 201, 202, 203, 204, 205, 206) arranged or, a generally circular rotatable gantry (12, 12′, 12″, 12′″) around an imaging region that emits emission radiation. The gamma detectors are each disposed at a fixed equal distance (R, R2, R3, R5) from an imaging isocenter (22, 22′, 22′, 22″) to rotate in a fixed radius circular orbit. Each gamma detector includes a radiation sensitive surface (72) that responds to the emission radiation and a slat collimator (70) that spins about an axis 88. Resolution and sensitivity at the fixed radius are selected by selecting collimator slat height (Wz) and spacing (G) and radiation sensitive surface width (Cy). The gamma detectors and rotating gantry are enclosed in an optically opaque toroidal housing (14) that defines a generally circular bore (16) that admits imaging subjects over a range of sizes.
摘要:
A method of ML-EM image reconstruction is provided for use in connection with a diagnostic imaging apparatus (10) that generates projection data. The method includes collecting projection data, including measured emission projection data. An initial emission map and attenuation map are assumed. The emission map and the attenuation map are iteratively updated. With each iteration, the emission map is recalculated by taking a previous emission map and adjusting it based upon: (i) the measured emission projection data; (ii) a reprojection of the previous emission map which is carried out with a multi-dimensional projection model; and, (iii) a reprojection of the attenuation map. As well, with each iteration, the attenuation map is recalculated by taking a previous attenuation map and adjusting it based upon: (i) the measured emission projection data; and, (ii) a reprojection of the previous emission map which is carried out with the multi-dimensional projection model. In a preferred embodiment, with source-assisted reconstruction, the recalculation of the attenuation map is additionally based upon: (iii) measured transmission projection data; and, (iv) a reference or blank data set of measured transmission projection data taken without the subject present in the imaging apparatus (10).
摘要:
A diagnostic imaging system includes oppositely disposed radiation detectors (32, 34) configured to detect coincidence radiation events caused by a substance injected into a subject which generates positron emissions. A coincidence data processor (40) collects and processes the radiation detected by the detectors (32, 34) and a coincidence circuitry (44) matches and compares the detected events to determine coincidence. Coincidence data is generated and stored in a coincidence data memory (46). A collimated radiation detector (50) is disposed at an angle to the coincidence radiation detectors (32, 34) and is configured to detect single photon radiation traveling along a selected projection path determined by a collimator (52) mounted on a front face of the collimated radiation detector (50). A single photon data processor (60) generates collimated data (74) based on the radiation detected by the collimated radiation detector (50). A combiner (80) selectively combines the coincidence data (46) and the collimated data (74) and the combined data is reconstructed into an image representation (84) of a region of interest.
摘要:
A nuclear camera system includes oppositely disposed radiation detectors (10a, 10b) which view an examination region 14 wherein a subject 16 is received therein. During a diagnostic scan, a motor and drive assembly (18) concurrently moves the detectors (10a, 10b) in a straight path along a longitudinal axis (20) for a selected time interval. The radiation detectors (10a, 10b) are positioned at a first angle at which the subject is viewed and the angle is maintained through the scan. A data processor (23) collects the data from the detected radiation and a coincidence circuitry (26) determines coincidence radiation events occurring on the detectors 10a, 10b. A first set of image data is generated for the first angular view and stored in a view memory (28). A second scan is performed where the detectors (10a, 10b) are shifted to a second angular view and the detectors are moved along the longitudinal axis for a second selected time interval. Radiation data is collected and a second set of image data is generated for the second scan. The first and second sets of image data are combined and a reconstruction processor (50) reconstructs the combined data into an image representation or a whole-body tomographic image (60).