Method for reconstructing an image from measured values obtained by helical scanning of an inspection object using a CT apparatus and CT apparatus for carrying out this method

摘要

PROBLEM TO BE SOLVED: To improve the handleability of a CT device by weighting a measured value according to a weighting function corresponding to a spatial interval in the axial direction of spiral scanning from the plane of an image to reconstitute the image concerning all the measured values positioned in a longest distance from the plane of the image concerning each angle of projection. ;SOLUTION: This CT device is provided with an X-ray source 1 with a focal point 2, irradiates an examination object (patient) 4 with an X-ray flux 3 in the shape of a pyramid diaphragmed by a diaphragm to and detects the patient 4 and transmitting X-rays by a detector 5. The source 1 and the detector 5 are rotated around a system axis 6 so as to irradiate the objects 4 with the X-rays at uarious projection angles (a). Then, the picture is reconstituted by a computer 8 from the result of detection and concerning each angle of projection, all the measured values positioned in the longest distance from the plane of the image are weight-processed according to the weighting function corresponding to a spatial interval in the axial direction of spiral scanning from the plane of an image to facilitate the reconstitution of the picture.;COPYRIGHT: (C)2000,JPO