X-ray CT apparatus

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.