Patent ID: 6493415
Filing Date: 2002-12-10
Classification: A61B

Abstract:
An X-ray computed tomography method, comprising:sequentially obtaining on a two-dimensional X-ray image sensor an X-ray projection image information of a curved sectional area by photographing with a rotary am tuning while locally radiating conical X-ray beams constantly passing through only a specific region from an X-ray generator, conforming a rotating center of the rotary arm and a center of the specific region in the curved sectional area along a dental arch, which is an object to be examined, or inside of a bow-shape of the curved sectional area, said rotary am including the X-ray generator and the two-dimensional X-ray image sensor facing to each other; arithmetically processing thus obtained X-ray projection image information by a backprojection method and computing a three-dimensional distribution information of an X-ray absorption coefficient of said curved sectional area; and calculating said three-dimensional distribution information of X-ray absorption coefficient on a projection line intersecting a normal line of a panoramic image layer at a specified angle for any regions of the panoramic image layer of said curved sectional area and obtaining a panoramic X-ray image of said curved sectional area seen from said projection line by expanding the calculated result on a two-dimensional plane.