Patent ID: 7486759

Claim:
An X-ray CT apparatus, which comprises an X-ray generating section that applies X-rays and an X-ray detecting section in opposing positions, and which rotates said X-ray generating section and X-ray detecting section with an imaging object arranged between said X-ray generating section and X-ray detecting section and also detects X-rays having been radiated from said X-ray generating section and transmitted through said imaging object in said X-ray detecting section to back-project X-ray CT data, so as to form a CT image, wherein said apparatus comprises an imaging mode selecting device for selecting: a panoramic imaging mode in which, during imaging, a rotational arm having said X-ray generating section and X-ray detecting section is rotationally driven while a rotational central axis of the rotational arm is moved, to form a panoramic image of said imaging object; and an offset scan/CT mode in which a CT image of said imaging object is constructed on the basis of X-ray CT data obtained by rotating the rotational arm around a rotational central axis wherein the rotational arm is set in such a position as a part of a region of interest of said imaging object is constantly irradiated with a cone beam radiated from said X-ray generating section and detected in said X-ray detecting section.