Patent ID: 9282935
Filing Date: 2016-03-15
CPC Classification: A61B

Claim Text:
1. An X-ray CT apparatus configured to rotate an X-ray tube and an X-ray detector around a subject mounted on a table top, radiate X-rays with a cone angle enlarging from the X-ray tube to the subject, and acquire images of the subject based on the X-rays transmitted through the subject and detected by the X-ray detector, the X-ray CT apparatus comprising: the X-ray tube, which includes a radiation surface of the X-rays and is configured such that a size of an effective focal point, which is a point when the radiation surface is viewed from a side on which the X-rays are radiated, is small at one end of the cone angle and is increased toward another end of the cone angle; the X-ray detector, which is configured to include at least two divided ranges, one range is configured to include a small detection range in which X-ray detection elements of a small size for detecting the X-rays radiated from the X-ray tube are arrayed, the other range is configured to include a large detection range in which X-ray detection elements of a large size for detecting the X-rays radiated from the X-ray tube are arrayed, and the radiation surface and the X-ray detector are configured such that positions thereof are transferable; and a control unit configured to select the small detection range or the large detection range, and transfer the positions according to the detection range selected and a position of the detection range to detect X-rays from the effective focal point in a size corresponding to the size of the X-ray detection elements of the X-ray detector.