摘要:
A method for calibrating a computed tomographic imaging apparatus having a gantry, a radiation source operable at a plurality of kVp's, and a detector array having a plurality of detector elements includes using a system detection function to estimate signals of each detector element that would have been detected through air and through a given thickness of water to determine estimated datasets. The estimated datasets are used to determine data pair sets each comprising a normalized water projection value and an ideal projection value for each detector element. The method further includes determining and storing a representation of a mapping function of the normalized water projections values to the ideal projection values in a memory of the computed tomographic imaging apparatus as a spectral calibration of the computed tomographic imaging apparatus.
摘要:
A method for determining a correction for beam hardening in CT images includes obtaining air scans at a plurality of kVp's, determining detection efficiencies for detector elements of the CT imaging apparatus, and estimating projection values through a combination of at least two different materials of different thicknesses. The method further includes determining a transfer function that translates the estimated projection values into ideal projection values for at least two of the different materials and storing the transfer function as the beam hardening correction for images of the CT imaging apparatus.
摘要:
A method for performing BIS correction includes scanning an object with a computed tomography (CT) system to obtain data, reconstructing an image using the obtained data, and using the image to perform BIS correction.
摘要:
A method for performing BIS correction includes scanning an object with a computed tomography (CT) system to obtain data, reconstructing an image using the obtained data, and using the image to perform BIS correction.
摘要:
A method for measuring an alignment of a detector is described. The method includes determining, by a processor, the alignment of the detector with respect to a collimated radiation beam. The determination of the alignment is based on a plurality of signals from a first cell of the detector and a second cell of the detector, and is independent of a shape of the collimated radiation beam.
摘要:
Systems, processes and apparatus are described through which non-destructive imaging is achieved, with equivalent or increased contrast, in comparison to conventional approaches, and that facilitate reduced dosage of X-rays delivered to the object or patient being imaged.
摘要:
A method for determining tracking control parameters for positioning an x-ray beam of a computed tomography imaging system, the imaging system including a movable collimator positionable in steps and a detector array including a plurality of detector elements arranged in rows and channels, the rows extending from a detector A-side to a detector B-side. The method includes determining a detector A-side and a detector B-side target beam penumbra position, computing a plurality of Z-ratio curves corresponding to different detector rows and detector channels, and comparing the Z-ratio curves at the detector A-side and detector B-side target beam positions to determine the optimal Z-ratio curve and corresponding detector channels and rows for controlling the X-ray beam positioning.
摘要:
A computed tomography assembly is providing including an x-ray gantry assembly, an x-ray source projecting a beam of x-rays, a detector assembly positioned opposite the x-ray source and receiving the beam of x-rays, and a control mechanism in communication with the x-ray source and the detector assembly. The control mechanism includes logic adapted to: execute at least one scout scan of the object to produce a first scout scan image; generate an elliptical patient model based on the first scout scan image; match the elliptical patient model to a phantom diameter approximation; generate a dose report based on the phantom diameter approximation; and display said dose report on a display in communication with the control mechanism.
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:
A method and system for automatically determining regions in scanned object are provided. The method includes performing a scout scan of an object and automatically determining regions within the object based on attenuation information from the scout scan.