Abstract: An X-ray computer tomography apparatus includes an X-ray tube, an X-ray detector, a rotating mechanism, a reconstruction unit which reconstructs multislice or volume image data based on the projection data detected by the X-ray detector, a profile generating unit which generates a CT value profile in the slice direction for each pixel by using image data, a profile portion extraction unit which extracts a profile portion exceeding a predetermined threshold from each of the CT value profiles, a scattered radiation distribution estimation unit which estimates a scattered radiation distribution centered on the profile portion based on the CT value integral and width of the profile portion, and a scattered radiation correction unit which corrects the image data based on the estimated scattered radiation distribution.

Abstract: An X-ray computer tomography apparatus includes an X-ray tube, a two-dimensional array type X-ray detector, a rotating mechanism, a pair of collimators, a collimator moving mechanism which separately moves the pair of collimators in a direction almost parallel to a rotation axis, a reconstruction processing unit which reconstructs image data in a reconstruction range, and a collimator control unit. The collimator control unit controls the position of each collimator in accordance with the distance between an X-ray central plane corresponding to a cone angle 0° and an end face of the reconstruction range. The collimator moving mechanism moves each of the pair of collimators in the range from the outermost position corresponding to the maximum cone angle to the innermost position offset from a position corresponding to a cone angle of nearly 0° to the opposite side.

Abstract: A control unit performs helical scanning an subject while moving a top along a direction substantially parallel to a body axis. An acquisition unit acquires projection data via an X-ray detector. A projection data extraction unit extracts a projection data set necessary for the reconstruction of image data associated with a predetermined slice position from the projection data. A weighting unit assigns a smaller weight to first projection data of the extracted projection data than a weight assigned to second projection data, the first projection data being acquired outside a predetermined period including a predetermined acquisition time of the projection data at the predetermined slice position, the second projection data being acquired within the predetermined period. A reconstruction processing unit reconstructs image data on the basis of the first projection data and the second projection data to which the weights are assigned.

Abstract: The X-ray CT apparatus that performs a scan after a pre-scan, comprising a reconstruction part reconstructing the pre-scan image of said subject to be examined from transmission data detected by said detector during said pre-scan, and also reconstructing the scan image of said subject to be examined from the transmission data detected by said detector during said scan; and a scan controlling part initiating a scan by directly changing the helical pitch of said bed from the stopped position for said pre-scan to the position toward an ending edge of the reconstruction area of the image. The scan controlling part initiates the scan at a first helical pitch by which X-rays for a predetermined number of views can be emitted at a starting edge of the reconstruction area of the image, and, after X-rays for the predetermined number of views is emitted, the scan at a second helical pitch continues.

Abstract: Noise originating from the difference between a second dose as an X-ray dose used for simulation and a first dose as an X-ray dose associated with raw data obtained by past imaging operation is calculated. Simulation pure raw data as information associated with a photon count and noise which are predicted to be detected by a plurality of X-ray detection elements when imaging is performed by using X-rays of the second dose is generated on the basis of the calculated noise and the raw data obtained by past imaging operation. A simulation image predicted to be obtained by imaging operation using X-rays of the second dose is generated by using the simulation pure raw data and displayed.

Abstract: A cerebral ischemia diagnosis assisting apparatus comprises a storing portion for storing multi-slices or volume data with regard to the head portion of a subject, an image generating portion for generating a tomography image of a brain from the multi-slices or the volume data, an image processing portion for processing the tomography image for generating a contrast highlighting image and a brain sulci highlighting image or either thereof, and a display portion for displaying the tomography image along with the contrast highlighting image and the brain sulci highlighting image.