Method and apparatus for collecting X-ray absorption data in X-ray computed tomography apparatus

摘要

In a method of collecting X-ray absorption data in an X-ray tomographic apparatus, an X-ray tube and an X-ray detector arranged to face each other via a body are caused to undergo reciprocation along a plane section of the body for collecting X-ray absorption data of the plane section in a given angular aspect. Two different kinds of X-ray absorption data dependent upon respective different energy levels are collected on the basis of different tube voltage during the respective forward and return movements in one reciprocation. After one reciprocation, the X-ray tube and X-ray detector are rotated by a predetermined angle relative to the body. The reciprocation and rotation are alternately repeated to collect X-ray absorption data of the plane section of the body in various angular aspects. The accuracy of the CT value can be increased using the two different kinds of X-ray absorption data during the forward and backward movements and also the difference between these two X-ray absorption data.