Patent application number | Description | Published |
20130336443 | SPARSE AND ENERGY DISCRIMINATING COLLIMATED DETECTOR ELEMENTS TO ASSIST SCATTER EVALUATION IN CT IMAGING - A computed-tomography apparatus that includes a CT scanner including an X-ray source and a detector covering respective angle ranges in the axial and transaxial planes of the CT scanner. The CT detector includes first detector elements disposed on a first surface to capture incident X-ray photons emitted from the X-ray source, and second detector elements sparsely disposed on a second surface different from the first surface, the second surface being farther away from the scanner than the first surface, the second detector elements being smaller in number than the first detector elements. Each of the second detector elements is reachable only by X-ray photons originating in a small angle range around a line connecting the X-ray source and a center of the surface of the detector element, the small angle range being determined by the predetermined distance separating the first and second surfaces and a size of the detector element. | 12-19-2013 |
20130343517 | APPARATUS, DETECTOR, AND METHOD FOR APPLYING A PIXEL BY PIXEL BIAS ON DEMAND IN ENERGY DISCRIMINATING COMPUTED TOMOGRAPHY (CT) IMAGING - A Computed Tomography (CT) method, apparatus, and detector, which includes a plurality of energy-discriminating detector elements configured to capture incident X-ray photons emitted from an X-ray source. Each of the plurality of energy-discriminating detector elements of the detector is configured to have a respective bias voltage individually switched ON or OFF, based on a signal received from a controller. | 12-26-2013 |
20140105354 | SPARSE AND ENERGY DISCRIMINATING COLLIMATED DETECTOR ELEMENTS TO ASSIST SCATTER EVALUATION IN CT IMAGING - A computed-tomography apparatus that includes a CT scanner including an X-ray source and a detector covering respective angle ranges in the axial and transaxial planes of the CT scanner. The CT detector includes first detector elements disposed on a first surface to capture incident X-ray photons emitted from the X-ray source, and second detector elements sparsely disposed on a second surface different from the first surface, the second surface being farther away from the scanner than the first surface, the second detector elements being smaller in number than the first detector elements. Each of the second detector elements is reachable only by X-ray photons originating in a small angle range around a line connecting the X-ray source and a center of the surface of the detector element, the small angle range being determined by the predetermined distance separating the first and second surfaces and a size of the detector element. | 04-17-2014 |
20140233693 | APPARATUS AND METHOD FOR COUNT LOSS CALIBRATION OF PHOTON-COUNTING DETECTORS IN SPECTRAL COMPUTED TOMOGRAPHY IMAGING - A method for photon count-loss calibration in a computed-tomography (CT) scanner, including capturing incident X-ray photons via a plurality of energy-discriminating detectors, determining photon counts of the captured incident X-ray photons in a plurality of energy windows at each energy-discriminating detector, and adjusting the determined photon counts in each energy window for each energy-discriminating detector based on a pre-determined photon count-loss look-up table and the determined photon counts. | 08-21-2014 |
20140233694 | APPARATUS AND METHOD FOR ANGULAR RESPONSE CALIBRATION OF PHOTON-COUNTING DETECTORS IN SPARSE SPECTRAL COMPUTED TOMOGRAPHY IMAGING - A method for detector angular response calibration in computed-tomography (CT) comprising capturing incident X-ray photons, emitted from an X-ray source, via a plurality of energy-discriminating detectors, determining photon counts of the captured incident X-ray photons in a plurality of energy windows at each energy-discriminating detector, and adjusting the photon counts based on a pre-determined detector angular response calibration look-up table for a given view for each energy-discriminating detector at each energy window. | 08-21-2014 |
20140270056 | DYNAMIC ALIGNMENT OF SPARSE PHOTON COUNTING DETECTORS - An apparatus and method for controlling movement of a plurality of fixed detectors arranged in a computed tomography (CT) system that includes a rotating X-ray source. The method including obtaining a view angle of the X-ray source, determining a tilt angle for a detector of the plurality of detectors that is within a scan field-of-view of the X-ray source at the obtained view angle so that an outer face of the detector directly faces the X-ray source, and causing the detector to be moved to the determined tilt angle. | 09-18-2014 |
20140314196 | TILTED DETECTOR ARRAY FOR MEDICAL IMAGING SYSTEMS INCLUDING COMPUTED TOMOGRAPHY - A medical imaging system can include a frame that has a bore that has a central longitudinal axis that intersects a target area for imaging, and a radiation source to emit radiation in radial directions towards the target area to form a fan or cone of emitted radiation that irradiates a cross-section of the target area with respect to the longitudinal axis. The system can include one or more detector arrays including a plurality of detector segments that extend along a detector axis that extends in a direction that is effectively parallel to the longitudinal axis, such that radiation emitted from the radiation source passes through the target area and is incident on one or more of the detector segments. The detector segments can each include a detecting surface that is tilted such that the detecting surface has a tilt (e.g., a non-zero slope) with respect to the detector axis. | 10-23-2014 |
20140314211 | PILEUP CORRECTION METHOD FOR A PHOTON-COUNTING DETECTOR - A method and apparatus for determining a parameter vector that includes a plurality of parameters of a detector pileup model of a photon-counting detector, the detector pileup model being used for pileup correction for a spectral computed-tomography scanner. The method includes setting values of the parameters, the parameters including a dead time parameter and individual probabilities of different pileup events, the probabilities including a probability of single photon events, a probability of double quasi-coincident photon events, and a probability of at least three quasi-coincident photon events. The method include determining, using (1) a detector response model, (2) an incident spectrum, and (3) the set values of the parameter vector, a plurality of component spectra, each component spectrum corresponding to one of the individual probabilities of the different pileup events, and summing the plurality of component spectra to generate an output spectrum. | 10-23-2014 |
20140328451 | APPARATUS AND METHOD FOR DYNAMIC CALIBRATION OF SPECTRAL CT WITH ROTATING X-RAY SOURCE AND STATIONARY ENERGY DISCRIMINATING DETECTORS - An apparatus and method for dynamically calibrating a computed-tomography (CT) scanner that includes a rotating X-ray source and a plurality of stationary energy-discriminating detectors configured to capture incident X-ray photons emitted from the X-ray source. A bowtie filter with a unique geometry and material composition is used to generate reference beams of a desired intensity. The apparatus includes a processor that is configured to remove a scattering background based on data obtained from the reference beams and compute a change in a predetermined calibration function. | 11-06-2014 |
20140341333 | APPARATUS AND METHOD FOR COLLIMATING X-RAYS IN SPECTRAL COMPUTER TOMOGRAPHY IMAGING - A detector includes a photon-counting detector (PCD) layer and a cathode layer arranged adjacent to the PCD layer. The detector further includes a plurality of pixilated anodes arranged adjacent to the photon-counting detecting layer on a side opposite to the cathode layer. The detector also includes a plurality of collimator segments arranged above the cathode layer so as to block a portion of X-ray photons emitted from an X-ray source from reaching the anodes, where each collimator segment is arranged above a portion of at least one anode. | 11-20-2014 |
20140355853 | NOISE BALANCE PRE-RECONSTRUCTION DATA DECOMPOSITION IN SPECTRAL CT - More than two acquired energy or spectral M bins are used for photon counting detectors in a CT system. In the pre-reconstruction data decomposition, the measured photo counts in the M acquired spectral bines are combined into a predetermined fewer number of processed or weighted spectral bines N, which is at least two in number and represents a number of selected basic materials. Since the N basis materials are selected in the imaged subject where N12-04-2014 | |
20140376689 | APPARATUS AND METHOD FOR REDUCING X-RAY FLUX IN SPECTRAL CT - An apparatus and method for reducing the X-ray flux in a computed-tomography (CT) scanner that includes a rotating X-ray source and a plurality of stationary photon-counting detectors configured to capture incident X-ray photons emitted from the X-ray source. A bowtie filter equipped with an edge filter that can be positioned in a reconfigurable manner such that the high X-ray flux at the leading edge of an X-ray fan beam incident on the detector is reduced. The CT apparatus includes a processor that is configured to compute the displacement of the edge filter in either a static or dynamic manner such that that the intensity of X-ray flux at the detectors in within acceptable operating limits. | 12-25-2014 |