Abstract: An X-ray computed tomographic (CT) system includes: a beam-hardening correction block that corrects first projection information in terms of the beam-hardening effect so as to produce second projection information; a first fitting block that fits a first function to the second projection information so as to produce third projection information; a second fitting block that fits a second function to the third projection information values that are provided as functions having as independent variables the second projection information values sampled in relation to all the views and each of the channels of an X-ray detector; and a correction coefficient modification block that modifies a second correction coefficient, which is calculated using a second phantom larger in dimensions than a first phantom, using a first correction coefficient calculated using the first phantom.

Abstract: An object of the present invention is to calculate a more accurate beam-hardening correction coefficient. A phantom having an oblong section or a phantom having an annular (sector) section and a uniform thickness is positioned in an X-ray CT system, and scanned from plural directions in order to acquire a plurality of views. The results of the scan are used to calculate a correction coefficient that is used to correct projection information to be acquired from a subject.

Abstract: For the purpose of providing a beam hardening post-processing method that can improve the accuracy of channel-by-channel correction on a BH effect easily and yet taking a non-linear effect into account, phantoms of different diameters are disposed at a position offset from an imaging center to acquire projection information having a transmission length of an X-ray beam varying from view to view (Step S501), hence, acquire projection information having a projection information value varying from view to view, for each channel, correction factors are determined (Step S506), and a corrective function containing even a non-linear effect is determined by higher-order function fitting from the correction factors (Step S508); and therefore, correction with high accuracy can be achieved in the channel-by-channel correction on the projection information values conducted after BH correction, and moreover, correction with high accuracy can be achieved using a smaller amount of phantom projection information, thus reduci

Abstract: In order to efficiently obtain projection data having a variety of slice widths (slice patterns) in one scan, an X-ray CT apparatus is provided in which an X-ray tube 40 and an X-ray detector 70 are opposed to each other interposing a subject 100, in which detector a multiplicity of X-ray detector elements are linearly arranged in the channel arrangement direction to form a plurality of rows in the subject body axis direction, for reconstructing a CT tomographic image of the subject based on detected signals from the X-ray detector, wherein the X-ray CT apparatus comprises signal duplicating means 81a for duplicating channel detected signals of the X-ray detector 70 and distributing the duplicated signals to a plurality of groups a, b, etc.; and signal combining means 81b that can combine the distributed duplicated signals in each group in an arbitrary pattern across the detector rows for each channel.

Abstract: In order to efficiently obtain projection data having a variety of slice widths (slice patterns) in one scan, an X-ray CT apparatus is provided in which an X-ray tube 40 and an X-ray detector 70 are opposed to each other interposing a subject 100, in which detector a multiplicity of X-ray detector elements are linearly arranged in the channel arrangement direction to form a plurality of rows in the subject body axis direction, for reconstructing a CT tomographic image of the subject based on detected signals from the X-ray detector, wherein the X-ray CT apparatus comprises signal duplicating means 81a for duplicating channel detected signals of the X-ray detector 70 and distributing the duplicated signals to a plurality of groups a, b, etc.