Patent classifications
G01T1/29
Multimodal imaging apparatus
A multimodal imaging apparatus (1a, 1b) including scintillator elements (31) for capturing incident gamma quanta (25, 61) and for emitting scintillation photons (26) in response to said captured gamma quanta (25, 61). Photosensitive elements (33) capture the emitted scintillation photons (26) and determine a spatial distribution of the scintillation photons. The imaging apparatus (1a, 1b) is configured to be switched between a first operation mode for detecting low energy gamma quanta and a second operation mode for detecting high energy gamma quanta. The scintillator elements are arranged to capture incident gamma quanta (25, 61) from the same area of interest (65) in both operation modes. The scintillator elements (31) include a first region with high energy scintillator elements (27) for capturing high energy gamma quanta and a second region with low energy scintillator elements (29) for capturing low energy gamma quanta. A positioning mechanism (35) changes the orientation of the scintillator elements (31), in particular for tilting the scintillator elements (31), to switch between operation modes.
Direct conversion radiation detector digital signal processing electronics
A system (100) includes a photon counting detector array (116) including a direct conversion material (118) and a plurality of detector pixels (120) affixed thereto, and a split signal corrector (126) that corrects the output of the plurality of detector pixels for split signals. A method includes receiving an output signal of each of a plurality of detector pixels affixed to a direction conversion material of photon counting detector array, and correcting the output of the plurality of detector pixels for split signals. A computer readable storage medium encoded with computer readable instructions, which, when executed by a processer, cause the processor to: receive an output signal of each of a plurality of detector pixels affixed to a direction conversion material of photon counting detector array, and correct the output of the plurality of detector pixels for split signals.
Multi-spectral static CT apparatuses
Multi-spectral static CT apparatuses are disclosed. The apparatus includes a ray source in a form of multiple distributed spots, multiple columns of detectors, a data acquisition device, an article carrying and control device, and a multi-spectral projection data processing device. An object of the present disclosure is to combine static CT scanning technology with multi-spectral analysis technology. It has an advantage of a static CT system, such as high scanning speed, simple mechanic structure, and/or cost reduction due to omission of slip ring. It also can perform identification of material in an article, and can be widely applied in occasions such as safety inspection, and smuggling suppression at customs.
Calibrating modular charged particle detector arrays
A charged particle detector array includes one or more pairs of super modules, one super module in a pair of super modules is positioned above a volume of interest (VOI), and the other super module in the pair of super modules is positioned below the VOI. This calibration technique first calibrates individual super modules in the one or more pairs of super modules while treating each super module being calibrated as a rigid body. Each super module in the one or more pairs of super modules further includes multiple vertically-stacked modules, and each module in the multiple vertically-stacked modules is composed of multiple layers of drift tubes. The calibration technique then calibrates individual modules in each of the super modules while treating each module being calibrated as a rigid body. Next, the calibration technique calibrates individual drift tubes in each layer of the modules.
METHOD FOR IMPROVING TIMING RESOLUTION USING DEPTH OF INTERACTION CORRECTION IN PET DETECTOR
A method for determining depth-of-interaction correction in a PET system includes modifying crystal and readout configuration to improve depth-dependent arrival profile of scintillation photons, creating a photon dispersion model within a scintillator crystal, measuring photon arrival profile of individual gamma ray event, deriving an estimated depth-of-interaction, and deriving a gamma ray event time based on a time stamp corrected with the estimated depth-of-interaction. The method can include modeling dispersion at different depths of interaction within the scintillator crystal; providing a reflector layer to delay back-reflected photons; providing two respective readouts for the same gamma ray event from two respective pixels optically coupled by a backside reflector or modified crystal configuration, calculating a time difference of the photon arrival at the two pixels, and estimating the depth-of-interaction by applying a statistical weighting. A non-transitory computer readable medium including program code to instruct a processor to determine depth-of-interaction correction is also disclosed.
APPARATUS FOR DETECTING POSITION OF RADIATION SOURCE
The present invention relates to an apparatus for determining the location of a radiation source. The apparatus for determining the location of a radiation source according to the present invention comprises: a collimator part for selectively passing radiation therethrough according to the direction in which the radiation is incident; a scintillator part for converting the radiation incident from the collimator part into a light ray; a first optical sensor for converting the light ray incident from one end of the scintillator part into a first optical signal; a second optical sensor for converting the light ray incident from the other end of the scintillator part into a second optical signal; and a location information acquisition part for acquiring information on the location where the light ray is generated in the scintillator part, by using the second optical signal and the second optical signal.
Detector configuration with semiconductor photomultiplier strips and differential readout
A detector configuration that combines a plurality of elongated semiconductor photo-multiplier sensor strips coupled to a scintillator crystal block with a differential readout that will enhance the time resolution. This is permitted due to a reduction of electronic noise due to reduced cross talk and noise in the ground. In addition, the dead area is minimized and thus the efficiency of the photodetector is enhanced.
Garnet scintillator composition
A ceramic or polycrystalline scintillator composition is represented by the formula (Lu.sub.yGd.sub.3-y)(Ga.sub.xAl.sub.5-x)O.sub.12:Ce; wherein y=1±0.5; wherein x=3±0.25; and wherein Ce is in the range 0.01 mol % to 0.7 mol %. The scintillator composition finds application in the sensitive detection of ionizing radiation and may for example be used in the detection of gamma photons in the field of PET imaging.
Motion-corrected pet images
A method is disclosed for generating a motion-corrected PET image of an examination area in a combined MR-PET system. In an embodiment, the method includes recording PET events from the examination area in a first recording time frame; recording a number of MR images of the examination area in at least the first recording time frame; calculating an at least two-dimensional movement information of the examination area on the basis of the number of MR images, wherein the movement information describes the movement information of the examination area during the first recording time frame, and determining the motion-corrected PET image from the PET events using the calculated movement information.
TIME OF FLIGHT CALIBRATION IN DIGITAL POSITRON EMISSION TOMOGRAPHY
Time of flight (TOF) corrections for radiation detector elements of a TOF positron emission tomography (TOF PET) scanner are generated by solving an over-determined set of equations defined by calibration data acquired by the TOF PET scanner from a point source located at an isocenter of the TOF PET scanner, suitably represented as matrix equation Formula I=CS where Formula I represents TOF time differences, C is a relational matrix encoding the radiation detector elements, and S represents the TOF corrections. A pseudo-inverse C.sup.−1 of relational matrix C may be computed to solve S=C.sup.−1 Formula I. TOF corrections can be generated for a particular type of detector unit by identifying the radiation detector elements in C by detector unit. Further, multi-photon triggering time stamps can be adjusted to first-photon triggering based on Formula II where P1 is average photon count using first-photon triggering and Pm is a photon count using multi-photon triggering.