Abstract: A method of computed-tomography and a computed-tomography apparatus where a interpolation kernel width is adaptively determined as a function of the distance from the x-ray source to the reconstruction pixel. The width of the kernel is the projection of the reconstruction pixel on the detector. The method can be implemented in the channel direction. The method can also be implemented in the segment direction, or in the channel and segment directions at the same time. Backprojection is performed using the adaptive kernel width and may by used with helical and circular scanning, and with cone-beam or fan beam x-ray CT.

Abstract: The CT imaging system optimizes its image generation by substantially reducing artifacts caused by a known amount of readout time lag in the X-ray detectors or data acquisition system. Although each detector row takes the same amount of time to read out the signals, the time lag cumulates over the rows as each row is sequentially read out. The back-projection coordinates are correspondingly corrected based upon the above described delay.

Abstract: The CT imaging system optimizes its image generation by substantially reducing artifacts caused by a known amount of readout time lag in the X-ray detectors or data acquisition system. Although each detector row takes the same amount of time to read out the signals, the time lag cumulates over the rows as each row is sequentially read out. The back-projection coordinates are correspondingly corrected based upon the above described delay.

Abstract: An X-ray computed tomography apparatus includes an X-ray tube (101) which generates X-rays, a multi-channel X-ray detector (103) which detects X-rays transmitted through an object to be examined, a rotating frame (102) which is equipped with the X-ray tube and the X-ray detector, a reconstruction unit (114) which reconstructs an image on the basis of an output from the X-ray detector, and a control unit (121) which alternately shifts the X-ray focal spot of the X-ray tube along the rotating direction on the anode by a distance +? and a distance ?? for each view. The distance ? is set to ? = S ? ? O ? ? D · tan ( ? ? ? ? 2 ) where SOD is the distance between the X-ray tube and the rotation center, and ?? is the angle difference between adjacent views, such that X-ray focal spots in the adjacent views overlap each other at almost the same position.

Abstract: A method of computed-tomography and a computed-tomography apparatus where a interpolation kernel width is adaptively determined as a function of the distance from the x-ray source to the reconstruction pixel. The width of the kernel is the projection of the reconstruction pixel on the detector. The method can be implemented in the channel direction. The method can also be implemented in the segment direction, or in the channel and segment directions at the same time. Backprojection is performed using the adaptive kernel width and may by used with helical and circular scanning, and with cone-beam or fan beam x-ray CT.

Abstract: An X-ray computed tomography apparatus includes an X-ray tube (101) which generates X-rays, a multi-channel X-ray detector (103) which detects X-rays transmitted through an object to be examined, a rotating frame (102) which is equipped with the X-ray tube and the X-ray detector, a reconstruction unit (114) which reconstructs an image on the basis of an output from the X-ray detector, and a control unit (121) which alternately shifts the X-ray focal spot of the X-ray tube along the rotating direction on the anode by a distance +? and a distance ?? for each view. The distance ? is set to ? = S ? ? O ? ? D · tan ( ? ? ? ? 2 ) where SOD is the distance between the X-ray tube and the rotation center, and ?? is the angle difference between adjacent views, such that X-ray focal spots in the adjacent views overlap each other at almost the same position.

Abstract: A method of removing an imaging artifact in a medical image, including obtaining a first plurality of images, the first plurality of images collectively defining a first image volume; filtering the first plurality of images to create a second plurality of images, each image in the second plurality of images comprising an average of at least two images in the first plurality of images; selecting a first image from the first plurality of images; adding a lost noise image to a second image in the second plurality of images to create a noise restored image, the second image in the second plurality of images corresponding to the first image in the first plurality of images; determining a gradient image based on pixel values in the second plurality of images, the gradient image comprising a gradient value at each pixel location in the second image; and combining, based on the determined gradient image, the first image and the noise restored image to obtain a corrected image that does not contain the imaging artifac

Abstract: A method of computed-tomography and a computed-tomography apparatus where a flying focal spot x-ray interpolation interlacing is used. Weighted or non-weighted interlacing of zero values is performed, or interpolation interlacing is performed. The interpolation interlacing may be implemented as part of backprojection and or may be a separate process prior to backprojection. In both cases interlacing is performed on post-logged convolved data. The interpolation interlacing may also be incorporated into different parts of the processing chain, such as before convolution.

Abstract: An x-ray computed tomography system, method, and computer product that generates an x-ray beam with an x-ray generator and detects with an x-ray detector at least one characteristic of the x-ray beam generated by the x-ray generator, after the x-ray beam has passed through an object, the system including a converting unit configured to obtain analog projection data outputted by the x-ray detector and to convert the analog projection data to digital projection data, and a processing unit configured to obtain the digital projection data from the converting unit, to detect overflow digital projection data that overflows a measuring range of the computed tomography system, and to correct the overflow digital projection data of the digital projection data by using a curve fitting function.

Abstract: A method of removing an imaging artifact in a medical image, including obtaining a first plurality of images, the first plurality of images collectively defining a first image volume; filtering the first plurality of images to create a second plurality of images, each image in the second plurality of images comprising an average of at least two images in the first plurality of images; selecting a first image from the first plurality of images; adding a lost noise image to a second image in the second plurality of images to create a noise restored image, the second image in the second plurality of images corresponding to the first image in the first plurality of images; determining a gradient image based on pixel values in the second plurality of images, the gradient image comprising a gradient value at each pixel location in the second image; and combining, based on the determined gradient image, the first image and the noise restored image to obtain a corrected image that does not contain the imaging artifac

Abstract: An x-ray computed tomography system, method, and computer product that generates an x-ray beam with an x-ray generator and detects with an x-ray detector at least one characteristic of the x-ray beam generated by the x-ray generator, after the x-ray beam has passed through an object, the system including a converting unit configured to obtain analog projection data outputted by the x-ray detector and to convert the analog projection data to digital projection data, and a processing unit configured to obtain the digital projection data from the converting unit, to detect overflow digital projection data that overflows a measuring range of the computed tomography system, and to correct the overflow digital projection data of the digital projection data by using a curve fitting function.

Abstract: An X-ray computed tomography apparatus includes a helical scanning device configured to collect projection data while at least one of a gantry and a couch moves along a body axial direction of an object on the couch when at least one of the gantry and the couch is tilted, the helical scanning device including an X-ray source configured to generate X-rays, and a detector disposed opposite the X-ray source and having detector elements arranged in a plurality of rows along the body axial direction, and a reconstructing device configured to reconstruct an image based on the projection data using cone-beam Feldkamp reconstruction.