Patent ID: 7773720

Claim:
A unit for X-ray CT imaging to be set in a panorama X-ray imaging apparatus having a cassette holder wherein a film cassette comprising an X-ray film or a digital sensor cassette comprising an electric X-ray detector for acquiring a panorama image data is set, the panorama X-ray imaging apparatus comprising an X-ray generator and an X-ray detector including the cassette holder, a rotation device comprising a rotation mechanism and a rotary arm, which rotation device rotating the X-ray generator and the X-ray detector while keeping them opposing to each other and interposing an object, wherein the rotation mechanism drives the rotary arm and moves a rotation center of the rotary arm, whereby a panorama tomography image of the object is acquired according to X-ray radiations from the X-ray generator, the unit for X-ray CT imaging comprising: a digital sensor cassette for CT imaging to be set in the cassette holder, including a two-dimensional X-ray detector for acquiring X-ray projection data for CT imaging of the object; a controller for controlling a timing of X-ray radiation for CT imaging, a radiation field of X-ray beam generated by the X-ray generator, and the rotation mechanism, and controls a position of the rotation center and a size of the radiation field of X-ray beam depending on the panoramic imaging and the CT imaging; and an image reconstructor which calculates to convert the X-ray projection data acquired by the two-dimensional X-ray detector to a distribution of X-ray absorption coefficients of the object and creates a tomography image data at sections of the object.