Patent classifications
G01T7/005
Data correction in X-ray imaging
A method for correction of an input dataset is disclosed. In an embodiment, the method includes acquisition of an input dataset comprising at least one data error; determination of a correction function; creation of a corrected output dataset by application of the correction function to the input dataset; and outputting of the corrected output dataset. The correction function is embodied to bring about a reduction of at least two data errors that mutually influence one another in the input dataset.
METHOD AND SYSTEM FOR CALIBRATING AN IMAGING SYSTEM
The disclosure relates to a system and method for medical imaging. The method may include: move, by a motion controller, a phantom along an axis of a scanner to a plurality of phantom positions; acquire, by a scanner of the imaging device, a first set of PET data relating to the phantom at the plurality of phantom positions; and store the first set of PET data as an electrical file. The length of an axis of the phantom may be shorter than the length of an axis of the scanner, and at least one of the plurality of phantom positions may be inside a bore of the scanner.
X-RAY RIPPLE MARKERS FOR X-RAY CALIBRATION
Various embodiments of the present disclosure include a C-arm registration system employing a controller (70) for registering a C-arm (60) to an X-ray ripple marker (20) including a ripple pattern (50) radially extending from a fixed point (40) of the X-ray ripple marker (20). In operation, the controller (70) identifies the ripple pattern (50) within an X-ray image generated from an X-ray projection by the C-arm (60) and illustrative of a portion or an entirety of the ripple pattern (50), the identification of the ripple pattern (50) within the X-ray image is characteristic of a pose of the X-ray projection by the C-arm (60) relative to the X-ray rippler marker (20). The controller (70) further analyzes the ripple pattern (50) within the X-ray image to derive one or more transformation parameters definitive of the pose of the X-ray projection by the C-arm (60) relative to the X-ray rippler marker (20), and registers the C-arm (60) to the X-ray ripple marker (20) based on the transformation parameter(s).
Combined n-type and p-type MOS-based radiation sensors for environmental compensations
An apparatus is disclosed comprising a metal oxide semiconductor capacitor (MOSCAP) comprising one or more gate layers disposed over a contiguous radiation-sensitive insulating layer, wherein the contiguous radiation-sensitive insulating layer comprises one or more contacting dielectric layers. A method may be employed to measure a value of a radiation-induced capacitance response of a metal oxide semiconductor capacitor (MOSCAP) from multiple non-contacting gate layers disposed over a radiation-sensitive layer comprising of one or more contacting dielectric layers to thereby enhance a sensitivity and a resolution of a radiation response of the MOSCAP.
METHOD FOR OPERATING AN X-RAY DEVICE
A method and device for operating an x-ray device including an x-ray emitter and an x-ray detector are provided. An alternating magnetic field is produced and emitted at the x-ray emitter. At least two sensors are included for capturing at least one physical variable correlating with the alternating magnetic field. An alignment of the x-ray detector relative to the x-ray emitter is determined based on the measurement.
Method for calibration of TOF-PET detectors using cosmic radiation
A method for calibration of TOF-PET detectors comprising polymeric scintillator strips and photoelectric converters, wherein cosmic radiation is used as a source of radiation, the method comprising the steps of: recording times of reactions of particles of cosmic radiation with the scintillator strips (101, 411, 421, 511, 521); determining spectra (301) of distribution of differences in the times at which pulses are recorded at ends of the scintillator strips (101, 411, 421, 511, 521) connected to photoelectric converters (102, 103, 412, 413, 422, 423, 512, 513, 522, 523); using the determined spectra (301) to determine timing synchronization constants of the photoelectric converters (102, 103, 412, 413, 422, 423, 512, 513, 522, 523), the constants being related to: delays within the electronics; speed of light propagation within the scintillator strip of the detection module; and resolution of the difference in times of the signals recorded at the ends of the module.
CLOCK SYNCHRONIZATION BETWEEN TIME CALIBRATION BOARDS
Methods, devices and computer-readable mediums for clock synchronization are provided. The methods include receiving a synchronizing clock in a unit clock cycle of a measuring clock, calibrating position information of a rising edge of the synchronizing clock in the unit clock cycle, determining a phase difference between the measuring clock and the synchronizing clock in the unit clock cycle based on the calibrated position information, and compensating a photon time in the unit clock cycle with the determined phase difference as a time compensation value.
METHOD FOR ESTIMATION AND CORRECTION OF GRID PATTERN DUE TO SCATTER
An apparatus for generating corrected X-ray projection data from target X-ray projection data obtained by performing an X-ray scan with a detector having an anti-scatter grid, and a method for creating a lookup table and generating corrected X-ray projection data. The apparatus includes a detector configured to detect incident X-rays, an anti-scatter grid configured to suppress scattered radiation incident on the detector, and an X-ray source configured to irradiate the target with X-rays. Processing circuitry is configured to cause the X-ray source to scan, using a peak kilovoltage (kVp), the target to produce the target projection data, determine a patient-to-detector distance (PDD) and an area irradiated (FS), transform the target projection data into a spatial frequency domain, determine scatter values by accessing the lookup table using the kVp, PDD, and FS values, and subtract the scatter values from the frequency components to obtain the corrected X-ray projection data.
Method for determining and correcting the stability of response of a semi-conductor matrix detector
Techniques for controlling a stability of response of a semi-conductor matrix imager composed of pixels, including a first phase of characterizing the stability of the pixels and a second phase of correcting the signals arising from the pixels during the measurements. The pixels are classed into stable pixels and unstable pixels according to a predetermined criterion, the unstable pixels being associated individually with a stable pixel whose characteristics serve as base for correcting signals arising from the unstable pixels.
Radiation detector calibration using voltage injection
Among other things, one or more systems and/or techniques for calibrating a direct conversion detector array are provided. An electrical charge is generated on an interface of a photoconductor (e.g., amorphous selenium) of the detector array when there is a change in voltage that is applied to the photoconductor. Such a change in voltage may occur because the voltage that is supplied to the photoconductor by a power supply is changed. The changed voltage causes an electrical charge to be produced, or causes a change in the net charge density at an interface of the photoconductor, that is substantially similar to the electrical charge that may be produced when radiation impinges the detector array. In this way, calibrations of the detector array (e.g., the generation of a uniformity map, defect table, etc.) may be performed without the emission of radiation and onsite or outside of a factory setting.