摘要:
An X-ray computed tomography apparatus includes a gantry, a reconstruction processing unit which generates first volume data on the basis of a projection data set which covers an angle range of 180°±a fan angle and also generates second volume data on the basis of a projection data set which covers an angle range of 360°, a correction data generating unit which generates correction data for reducing a cone beam artifact on the basis of a difference between the first volume data and the second volume data, and a correction unit which corrects the first volume data on the basis of the correction data.
摘要:
X-ray transmission data of a specific direction is extracted from X-ray transmission data obtained by rotating an X-ray tube irradiating an X-ray around an object. The outline of the object is calculated based on the X-ray transmission data of the specific direction. Then, based on this outline, the X-ray transmission data is corrected, and an image of the inside of the object is reconstructed from the corrected X-ray transmission data.
摘要:
An X-ray computed tomography apparatus includes a gantry, a reconstruction processing unit which generates first volume data on the basis of a projection data set which covers an angle range of 180°+a fan angle and also generates second volume data on the basis of a projection data set which covers an angle range of 360°, a correction data generating unit which generates correction data for reducing a cone beam artifact on the basis of a difference between the first volume data and the second volume data, and a correction unit which corrects the first volume data on the basis of the correction data.
摘要:
X-ray transmission data of a specific direction is extracted from X-ray transmission data obtained by rotating an X-ray tube irradiating an X-ray around an object. The outline of the object is calculated based on the X-ray transmission data of the specific direction. Then, based on this outline, the X-ray transmission data is corrected, and an image of the inside of the object is reconstructed from the corrected X-ray transmission data.
摘要:
To enable radiation rays to be efficiently used. A scout scan parameter setting unit sets a rotation movement position to which an X-ray tube and an X-ray detector are moved so as to rotate around a subject on the basis of subject information of a subject on which a scout scan is performed at the time of performing a scout scan. At the time of starting execution of the scout scan, a rotating unit moves the X-ray tube and the X-ray detector so as to rotate around the subject to the rotation movement position which is set by the scout scan parameter setting unit. After that, a scout scan is performed in the rotation movement position.
摘要:
To enable radiation rays to be efficiently used. A scout scan parameter setting unit sets a rotation movement position to which an X-ray tube and an X-ray detector are moved so as to rotate around a subject on the basis of subject information of a subject on which a scout scan is performed at the time of performing a scout scan. At the time of starting execution of the scout scan, a rotating unit moves the X-ray tube and the X-ray detector so as to rotate around the subject to the rotation movement position which is set by the scout scan parameter setting unit. After that, a scout scan is performed in the rotation movement position.
摘要:
A method for reconstructing an image that can be recognized stably during CAD. The method for reconstructing an image on the basis of a plurality of views of projection data items provided by X-rays having passed through a subject includes image reconstruction dedicated to a computer-aided detection (CAD) mode. The image reconstruction comprises a reconstruction function dedicated to the CAD mode, includes pre-processing that includes a noise removal filter for removing a noise from projection data, such as, a streaky artifact removal dedicated to the CAD mode, and also includes post-processing that includes a noise removal filter dedicated to the CAD mode.
摘要:
An image reconstructing method includes upon reconstructing an image using a multi-row detector having a plurality of detector sequences and on the basis of projection data D0 collected by a helical scan with a scan surface being tilted effecting, on the projection data, a tilt correcting process for correcting variations on every view, in positions of respective channels of the detector sequences with respect to a linear travel axis due to the inclination of the scan surface, projecting respective pixels in an X-ray penetration direction along lines parallel to an X axis or a Y axis on a reconstruction plane to determine the corresponding projection data and defining the same as backprojected pixel data of respective pixels constituting the reconstruction plane, and adding the backprojected pixel data of all views used in image reconstruction in association with the pixels to determine backprojected data.
摘要:
An object of the present invention is to utilize a distance, which is linearly moved for acceleration or deceleration, out of an overall distance linearly moved during a helical scan for the purpose of image reconstruction. Projection data is acquired even during acceleration or deceleration of linear movement made for a helical scan. The acquired projection data is utilized for image reconstruction. Moreover, during the acceleration of linear movement, while a tube current is being increased, projection data is acquired. During the deceleration of linear movement, while the tube current is being decreased, projection data is acquired.
摘要:
For the purpose of reducing exposure of a subject to unnecessary radiation by controlling the tube current according to the X-ray emitting direction with respect to a region to be examined in the subject, a transmission area S is calculated from a cross-sectional plane (S801) and an ellipticity R is calculated for the cross-sectional plane (S802, S803). An image SD of a region having the transmission area S is then calculated (S804), and a SD ratio of a region having the ellipticity R is calculated (S805). An image SD of a region having the transmission area S and ellipticity R is then calculated using the image SD and the SD ratio (S806). Next, a target SD is specified (S807), and the tube current that controls X-rays emitted in the major-axis direction in the cross-sectional plane of the subject is calculated using the image SD obtained at S806 and the target SD (S808), and the tube current that controls X-rays emitted in the minor-axis direction in the cross-sectional plane of the subject is calculated using the obtained tube current and R (S809).