Patent ID: 7535987
Filing Date: 2009-05-19
Classification: A61B,G01N,H05G

Abstract:
1. An X-ray CT apparatus, comprising: a plurality of X-ray tubes; a plurality of X-ray detectors corresponding to said plurality of X-ray tubes, respectively, each X-ray tube and corresponding X-ray detector forming a pair; a support mechanism which supports the X-ray tubes and the X-ray detectors to allow the X-ray tubes and the X-ray detectors to rotate about a single rotation axis; a reconstruction unit which reconstructs image data on the basis of outputs from the X-ray detectors; and a plurality of filters corresponding to said plurality of X-ray tubes, each filter having a characteristic in which an X-ray path length changes as a function substantially equal to an inverted Gaussian curve from the rotation center to two ends of an X-ray beam so as to reduce scattering radiation originating from X-rays generated by an X-ray tube of a first pair, but detected by an X-ray detector of a second, different pair; wherein said each filter has a characteristic in which an intensity of X-rays transmitted through the filter exceeds 90% of a maximum intensity at the rotation center at a middle portion less than 10 cm away from the rotation center, and an intensity at a peripheral portion more than 20 cm away from the rotation center is less than 50% of the maximum intensity at the rotation center.