X-ray CT apparatus and X-ray CT method

An X-ray computer tomography apparatus wherein a conical X-ray beam is radiated on a local area of an object while a rotary means with an X-ray generator and a two-dimensional X-ray image sensor faced to each other is rotated relative to the object which is disposed between the X-ray generator and the two-dimensional X-ray image sensor, and the obtained image is shown, said X-ray computer tomography apparatus comprising:

• a preliminary imaging means for imaging said object under plural positional conditions wherein positional relations among said X-ray generator, said object and said two-dimensional X-ray image sensor are varied;
• a positioning operation means for specifying the two-dimensional position of a target region in said object on plural fluoroscopic images, which are obtained by said preliminary imaging means and shown on a display means in array, with a crosswise cursor for specifying horizontal position and a vertical cursor for specifying longitudinal position, wherein when the horizontal position is being specified with said crosswise cursor, the same horizontal position is being positioned on other fluoroscopic images;
• a processing means for obtaining a three dimensional position of said target region in said object by calculating a two-dimensional positional data of said target region in said object;
• a position adjustment means for adjusting said positional relation among said X-ray generator, said object and said two-dimensional X-ray image sensor in such a manner that the rotary center comes to said three dimensional position of said target region in said object obtained from said processing means;
• a main imaging means for obtaining a tomogram of said object while said rotary means and said object are relatively rotated after adjusting with said position adjustment means;
• a display means;
• and
• an image invocation means having a function for displaying the tomogram in said target region as specified on said display means when said target region in said object is specified on said fluoroscopic image selected from those stored in said image storage means and displayed on said display, and/or a function for displaying the fluoroscopic image used for obtaining said region corresponding to the tomogram displayed on said display means while said tomogram selected from said plural tomograms stored in said image storage means is displayed on said display means.