The on the basis of the projection data D0 which was collected with

摘要

PROBLEM TO BE SOLVED: To reduce time for image reconstitution of an X-ray CT apparatus for acceleration by reducing the number of lines in the case of plane projection when a cone angle formed by a reconstitution surface (XY plane) and an X-ray beam is small and increasing the number of lines when the cone angle is large.;SOLUTION: Data D1 is obtained by the plane projection of projection data D0 collected by axial scanning using a multi-row X-ray detector or a plane X-ray detector having a plurality of detectors on a projection plane. Next, the data D1 plane-projected on each pixel constituting a plurality of lines in a direction parallel to the projection plane, which is a plurality of lines arranged at an interval of a plurality of pixels on a reconstitution area, is projected in the direction of X-ray transmission to obtain back projection pixel data D2 of each pixel constituting a line on the reconstitution area by the portion of the number of plane projection data lines depending on the angle of a reconstitution area plane and the X-ray beam. The plurality of lines are interpolated to obtain the back projection pixel data D2 of each pixel between the lines on the reconstitution areas.;COPYRIGHT: (C)2005,JPO&NCIPI