Abstract: A weighting function is created according to an arbitrary bio-movement correction range and a projection data angle for back-projection (width in the view direction used for reconstruction), set by a user, by considering the degree of the bio-movement and redundancy. By using this weighting function, an image reconstruction is performed. The bio-movement correction range is set as a correction angle width index ? expressing the width guaranteed as a slope portion of the weighting function. The projection data angle for back-projection (data width) is determined by considering the data redundancy, SN, time width (time resolution) contributing to the image. By determining the weight according to these two parameters, it is possible to apply reconstruction of projection data of all the scan ranges in the reconstruction of the tomogram and prevent lowering of the data contribution ratio as well as reduce the motion artifact, thereby obtaining a high-quality image.

Abstract: An image reconstruction area of a subject is divided into a plurality of image data segments, among projection data obtained by projection, projection data segments necessary for back projection processing are cut out for every image data segments and back projection processing is performed for every image data segments by making use of the cut out projection data segments. Further, detector addresses of the projection data to be used for the back projection processing are obtained from a plurality of limited number of detector addresses within the concerned image data segment region. As a result, a device is realized which permits to produce a high quality tomographic image with high speed by using a small amount of a high speed memory.

Abstract: A radiotomography apparatus according to the present invention includes a radiation detection device that irradiates radiation from a radiation source in multiple directions around an object to be examined and detects radiation transmitted through the object from the multiple directions; a table on which the object lies and which can move the object in a body axis direction of the object; reconstruction parameter setting device that sets reconstruction parameters that include an amount of movement of the table in the body axis direction, and that are used to reconstruct an image of the object; a reconstruction view area calculating device that calculates a reconstruction view area for at least one data segment that is necessary for a reconstruction calculation that is determined for each spatial position that is reconstructed based on the set reconstruction parameters; a reference segment position setting device that sets a reference segment position in the calculated reconstruction view area according to a p

Abstract: An image diagnosis supporting system comprising a means for reading in image data representative of the image of a subject acquired by a medical imaging apparatus, a means for detecting an abnormal shadow candidate satisfying at least one of a plurality of criteria for abnormal shadow criteria from the image thus read in, and a means for displaying the image thus read in and a marker indicative of the abnormal shadow candidate thus detected in a superimposed state. The image diagnosis supporting system is further provided with a means for setting criteria supporting judgment of the abnormal shadow candidate detected by the abnormal shadow candidate detecting means as judgment supporting criteria, and a control means for displaying the judgment supporting criteria thus set, the abnormal shadow candidate and the marker simultaneously on the display means. Accordingly, it is possible to support the user in accurately judging the type of an abnormal shadow candidate.

Abstract: An image reconstruction area of a subject is divided into a plurality of image data segments, among projection data obtained by projection, projection data segments necessary for back projection processing are cut out for every image data segments and back projection processing is performed for every image data segments by making use of the cut out projection data segments. Further, detector addresses of the projection data to be used for the back projection processing are obtained from a plurality of limited number of detector addresses within the concerned image data segment region. As a result, a device is realized which permits to produce a high quality tomographic image with high speed by using a small amount of a high speed memory.

Abstract: An image processing method comprises: an inputting step of inputting image data which is obtained by imaging a subject for a predetermined period of time with a medical imaging apparatus and is arranged in time series; an extracting along the time axis step of extracting pixels which satisfy a predetermined condition along the time axis from all the pixels arranged in time series for each pixel coordinate position with respect to each pixel in the image data; and a constructing step of constructing a two-dimensional or three-dimensional image based on the pixels extracted along the time axis in the extracting along the time axis step.

Abstract: An X-ray CT apparatus comprising a scanner that includes an X-ray source and an X-ray detector having two-dimensionally arranged X-ray detector elements, disposed on the opposite side of the subject to the X-ray source and carries out helical scanning around the revolving axis and an image processor for creating a tomogram of the subject from the data collected by helical scanning using the X-ray detector, wherein the image processor creates a tomogram by reconstructing an image from data on the subject including a plurality of sets of projection data of different phases of helical scanning at the same point on the revolving axis and adding the reconstructed images of different phases, whereby a good image is created while suppressing aritifacts.

Abstract: A tomograph which determines projection data phase range capable of back projection for each reconfigured voxel with an arbitrary value larger than ? so that the absolute values of cone angles at the ends of this phase range is minimized, calculates an approximate straight line for a curve indicating the position of a radiation source with respect to the channel direction position of parallel beam projection data obtained by a parallel beam of a parallel shape viewed from the go-around axis direction generated from the radiation source, and based on the determined projection data range capable of back projection, three-dimension back projects the parallel beam projection data subjected to filter processing created through a filter correction to the back projection region corresponding to the region in concern along the approximate irradiation trace of the radiation beam calculated using the calculated approximate straight line, thereby suppressing generation of the distortion attributed to data discontinuity,

Abstract: Three pairs of X-ray tubes (21A-21C) and single- or multiple-row detectors (31A-31C) are mounted on a rotary disc (49) installed in a scanner unit (12) at a rotational phase difference of 120°, and a deviation (offset) ?Z is set between the three pairs in a rotation axis direction of a subject (16) in accordance with ?Z=d×N, where d is the thickness of the row of the single- or multiple-row detectors (31A-31C), and N is an offset coefficient. Slice collimators (48A-48C) are provided to X-ray tubes (21A-21C) in the three pairs, and are rotated relative to the subject (16) to provide a high-quality tomographic image with high temporal resolution, less motion artifact and high space resolution.

Abstract: An X-ray CT apparatus comprising a scanner that includes an X-ray source and an X-ray detector having two-dimensionally arranged X-ray detector elements, disposed on the opposite side of the subject to the X-ray source and carries out helical scanning around the revolving axis and an image processor for creating a tomogram of the subject from the data collected by helical scanning using the X-ray detector, wherein the image processor creates a tomogram by reconstructing an image from data on the subject including a plurality of sets of projection data of different phases of helical scanning at the same point on the revolving axis and adding the reconstructed images of different phases, whereby a good image is created while suppressing aritifacts.

Abstract: A multi-slice x-ray CT apparatus has detectors arranged in rows, and projection data on a cross section of an object can be simultaneously measured, wherein the spiral pitch can be arbitrarily determined. A virtual detector row is virtually defined to compensate for lack of lines if the spiral pitch is larger than the number of pitches, so as to always create a high-quality image even if the relationship between the number of rows of detectors and the spiral pitches changes. The weight determined for the virtual detector row is distributed to the weights of projection data on the actual detectors used when the projection data on the virtual detector row is determined.