Patent ID: 7734006

Claim:
An X-ray CT apparatus, comprising: an X-ray source which irradiates X-rays; an X-ray detector which is arranged opposite to the X-ray source and detects said irradiated X-rays; a scanner having a rotary disk which rotatably supports the X-ray source and X-ray detector and a power source of the rotary disk; an image processing device which makes said scanner rotate in a state where an object is inserted in between said X-ray source and said X-ray detector to irradiate said object with X-rays from directions at a plurality of angles, and makes said X-ray detector detect X-rays transmitted through said object in directions at a plurality of angles as projection data, to reconstruct a tomographic image of said object by use of the projection data in the directions at the plurality of angles; a display device which displays said reconstructed tomographic image; a setting device which sets an X-ray irradiation condition including a combination of a tube current and a tube voltage supplied to said X-ray source; and a control device which supplies said X-ray source with said set X-ray irradiation condition, to perform scanning, wherein said setting device includes an X-ray irradiation condition information creating section configured to generate X-ray irradiation condition information, by use of a plurality of X-ray irradiation condition candidates and image quality indexes corresponding to the plurality of X-ray irradiation condition candidates, the image quality indexes being based on a transmission thickness of a scanning subject site of said object and an attenuation model of at least two tissues, and an X-ray irradiation condition information displaying section configured to cause the X-ray irradiation condition information to be displayed on the display device, for selection of an X-ray irradiation condition candidate from among the plurality of X-ray irradiation condition candidates, the X-ray irradiation condition being set to the selected X-ray irradiation condition candidate.