Patent classifications
A61B6/583
Self calibration method and apparatus for correcting offset angle in a photon counting computed tomography system
An apparatus, system and method for calibrating an x-ray apparatus including acquiring sinogram data by scanning a symmetrical phantom using a plurality of detector channels; generating mirror-copied sinogram data by mirror-copying at least one of first sinogram data and second sinogram data of the acquired sinogram data, wherein the first sinogram data and the second sinogram data are generated by dividing the sinogram data at a center detector channel of the plurality of detector channels; outputting a first reconstructed image by reconstructing the mirror-copied sinogram data; and determining a calibration parameter based on the first reconstructed image.
Calibration method for a spectral computerized tomography system
A calibration method for an x-ray computerized tomography system and a method of tomographic reconstruction are provided. The calibration method includes steps of measuring at least one point spread function (PSF) at each of a plurality of points, compressing each PSF, and in one or more storing operations, storing the compressed PSFs in a computer-accessible storage medium. The PSF measurements are made in a grid of calibration points in a field of view (FOV) of the system. In the measuring step, an absorber is positioned at each of the calibration points, and an x-ray projection is taken at least once at each of those absorber positions. In the method of tomographic image reconstruction, projection data from an x-ray tomographic projection system are input to an iterative image reconstruction algorithm. The algorithm retrieves and utilizes a priori system information (APSI) The APSI comprises comprising point spread functions (PSFs) of all voxels in a voxelization of the field of view that are compressed in the form of vectors of parameters. For utilization, each retrieved vector of parameters is decompressed so as to generate a discretized PSF.
IMAGE-GUIDED RADIATION TREATMENT WITH IMAGING DATA USING IMAGING RADIATION AT DIFFERENT ENERGY LEVELS
A method of image-guided radiation treatment is described. The method includes processing a first and second sets of image data to generate an enhanced image, wherein the enhanced image comprises a combination of the first and second sets of image data, wherein part or all of the image data comprises a target of a patient. The method also includes registering the enhanced image with another image to obtain a registration result and tracking the target using the registration result to generate tracking information. The method also includes directing treatment delivery to the target based on the tracking information obtained from the enhanced image.
ELECTRONIC CALIBRATION OF FOCAL SPOT POSITION IN AN X-RAY TUBE
Technology is described for calibrating a deflected position of a central ray of an x-ray tube to a radiation imager. An x-ray system includes an x-ray tube and a tube control unit (TCU). The x-ray tube includes a cathode that includes an electron emitter configured to emit an electron beam, an anode configured to receive the electron beam and generate x-rays with a central ray from electrons of the electron beam colliding on a focal spot of the anode, and a steering magnetic multipole between the cathode and the anode that is configured to produce a steering magnetic field from a steering signal. At least two poles of the steering magnetic multipole are on opposite sides of the electron beam. The TCU includes at least one steering driver configured to generate the steering signal. The TCU is configured to convert a position correction value to the steering signal.
SPECTRUM-NEUTRAL DETERMINATION OF CALCAREOUS DEPOSITS IN BLOOD VESSELS
A method is described for the determination of a calcium score for a patient to be examined with the aid of a CT system. The method is used to define patient-specific CT-acquisition parameters. In addition, material parameters for a model method for the generation of synthetic image data for virtual CT-acquisition parameters are calibrated using phantom image data recorded with reference CT-acquisition parameters. A calcium score assigned to synthetic phantom image data corresponds to a calcium score determined with phantom image data recorded with reference CT-acquisition parameters. Next, CT-projection-measurement data is acquired for a region of interest using the patient-specific CT-acquisition parameters. The acquired CT-projection-measurement data is used to generate synthetic image data using the calibrated model method. Finally, a calcium score is determined using a standard method on the basis of the synthetic image data. Also described is a calcium-score-determining device. Also described is a computed tomography system.
Radiation image processing apparatus and method
A composition information obtaining unit calculates a mammary gland/fat ratio and a first information obtaining unit obtains imaged contrast information representing a contrast of the radiation image. A second information obtaining unit sets target application condition of X-ray, and obtains target contrast information representing an intended contrast for the radiation image based on the intended application condition. A contrast correction amount determination unit determines a contrast correction amount based on the imaged contrast information and the target contrast information. An image processing unit performs image processing, including gradation processing based on the determined contrast correction amount, on the radiation image, and obtains a processed radiation image.
PHANTOM FOR QUALITY ASSURANCE OF MAGNETIC RESONANCE IMAGING AND COMPUTED TOMOGRAPHY FOR MULTI-ARTIFACT CORRECTION
The present invention relates to a phantom for quality assurance of magnetic resonance imaging (MRI) and computed tomography (CT) for multi-artifact correction. An aspect of the present invention provides a phantom capable of simultaneously evaluating performance of magnetic resonance imaging (MRI) and computed tomography (CT), the phantom including: a first hemispheric container; and a second hemispheric container which has the same structure and the same size as the first container, in which the first container and the second container are connected by being in direct contact with each other so as to form a symmetrical structure, each of the first container and the second container includes a teeth retainer into which a plurality of teeth mimics, which mimics teeth of a body, is inserted, and an insertion hole into which at least one bone mimic is inserted, and an interior of each of the first container and the second container is filled with at least one solution that mimics a brain metabolite.
Automated tracking of fiducial marker clusters in x-ray images
Various embodiments of the present technology generally relate to identification of tumor location. More specifically, some embodiments of the present technology relate automated tracking of fiducial marker clusters in x-ray images for the real-time identification of tumor location and guidance of radiation therapy beams. Some embodiments use processed CBCT projection images, an automated routine of reconstruction, forward-projection, tracking, and stabilization generated static templates of the marker cluster at arbitrary viewing angles. Breathing data can be incorporated into some embodiments, resulting in dynamic templates dependent on both viewing angle and breathing motion. In some embodiments, marker clusters can be tracked using normalized cross correlations between templates (either static or dynamic) and CBCT projection images.
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.
POST ACQUISITION CALIBRATION
A method of operating a tomographic imaging system whereby a plurality of radiographic images of an object are captured at a first orientation of the system's source and detector. After the radiographic images are captured and stored, geometric calibration data for the system is measured, corresponding to the first orientation of the system. A three dimensional image of the object is reconstructed using the measured geometric calibration data corresponding to the first orientation.