摘要:
The present invention provides a method for producing images of an object. The method includes dynamically helically scanning an object on a moving table utilizing a scanning imaging system. During the scan, projection views of the object are acquired and stored together with corresponding table locations. A plane for reconstruction of an image of the object is selected. The stored table locations are used to determine geometric variables applicable to the stored projection views; and the stored projection views are filtered and backprojected utilizing the geometrical variables to reconstruct an image of the object at the reconstruction plane.
摘要:
Methods and systems for scanning a patient by using a medical imaging device are provided. The methods include determining a defective cell in a row n of a detector of the medical imaging device, determining a mode of operation of the medical imaging device, estimating the output of the defective cell using the determined mode of operation and at least one of a conjugate sample of the defective cell, an adjusted conjugate sample of the defective cell, and an estimate of the output of the defective cell using an output of a corresponding cell in an adjacent row and reconstructing an image of the patient using the estimated value of the defective cell.
摘要:
A method and system for an improved data acquisition system with an image detector array and an image processing system which finds a malfunctioning cell, interpolates a signal for the malfunctioning cell using neighboring channels of the cell, and corrects the interpolation with an error rate found in performing interpolations on neighboring rows with cells which are not malfunctioning. The image processing system may include a DAS and a reconstruction system. The step of finding a malfunctioning cell may be accomplished through a variety of methods, such as measuring discrepancies between a cell's and its neighboring cell's average readings over time and exposing the cells to x-rays which should produce similar readings in all the cells and comparing the cells' signals, looking for discrepancies. The step of interpolating and the step of correcting may take into consideration cells within the same projection view as the malfunctioning cell.
摘要:
A CT system includes a gantry, an x-ray source, a detector, and a grating collimator that includes alternating first and second materials. The system includes a controller configured to emit a first beam of x-rays from a first focal spot and to a first detector pixel, wherein the first beam of x-rays passes along a ray and through one of the first materials of the grating collimator, and subsequently emit a second beam of x-rays from a second focal spot and to the first detector pixel, wherein the second beam of x-rays passes substantially along the ray and through one of the second materials of the grating collimator. The system includes a computer programmed to generate first and second kVp image datasets using data acquired from the first beam and second beams of x-rays, and reconstruct a basis material image of the object.
摘要:
A system and method for material decomposition optimization in the image domain include a non-transitory computer readable medium has stored thereon a sequence of instructions which, when executed by a computer, causes the computer to access a reconstructed basis material image. For a first voxel of the reconstructed basis material image, the instructions also cause the computer to optimize a concentration of a pair of materials (a,b) in the first voxel exclusively in the image domain and based on a first probability based on random perturbations and a second probability based on random perturbations. The optimization is further based on a third probability based on known materials and a fourth probability based on concentrations of the pair of materials in a pair of voxels neighboring the first voxel.
摘要:
A CT system includes a gantry, an x-ray source, a detector, and a grating collimator that includes alternating first and second materials. The system includes a controller configured to emit a first beam of x-rays from a first focal spot and to a first detector pixel, wherein the first beam of x-rays passes along a ray and through one of the first materials of the grating collimator, and subsequently emit a second beam of x-rays from a second focal spot and to the first detector pixel, wherein the second beam of x-rays passes substantially along the ray and through one of the second materials of the grating collimator. The system includes a computer programmed to generate first and second kVp image datasets using data acquired from the first beam and second beams of x-rays, and reconstruct a basis material image of the object.
摘要:
A method for reconstructing an image of an object includes scanning an object using a computed tomographic (CT) imaging apparatus to acquire projections of the object. A set of thresholds are determined utilizing the projections, and selected smoothing kernels are associated with the thresholds. The method further includes utilizing the smoothing kernels and the projections to produce smoothed projections in accordance with the thresholds and filtering and backprojecting the smoothed projections to generate an image of the object.
摘要:
A method for reconstructing an image of an object includes performing an air calibration on an imaging system to generate set of air calibration data, estimating an x-ray spectrum using the air calibration data, and reconstructing an image of an object using the estimated x-ray spectrum. An imaging system and a non-transitory computer readable medium are also described herein.
摘要:
A collimator for an imaging system includes a first region comprising a first one-dimensional array of apertures along a channel direction, and a second region comprising a second one-dimensional array of apertures along the channel direction, wherein an aspect ratio of the apertures of the first region is greater than an aspect ratio of the second region.
摘要:
A system, method, and apparatus includes a computed tomography (CT) system having a rotatable gantry, an x-ray source, a generator, a detector having pixels and positioned to receive x-rays, and a computer. The computer is programmed to acquire CT data representative of an object, determine a first subset of the CT data, determine a second subset of the CT data, and determine a difference between the first and second subsets of the CT data to identify a motion region in the object. The computer is also programmed to update image data reconstructed from a first portion of the first subset of the CT data and corresponding to the region and reconstruct an image based on the updated image data and non-updated image data. The non-updated image data is reconstructed from a second portion the first subset of the CT data.