Patent ID: 8442292

Claim:
An X-ray CT apparatus comprising: an X-ray source for applying X-ray; an X-ray detector that is disposed so as to face the X-ray source while an examinee is sandwiched between the X-ray source and the X-ray detector and detects an X-ray dose transmitted through the examinee; a gantry that has the X-ray source and the X-ray detector mounted therein and is rotatable around the examinee; a bed that is movable while the examinee is put on the bed; a control device that controls the X-ray source, the X-ray detector, the gantry and the bed; a periodic motion measuring device that measures a periodic motion of the examinee; an image processing device that generates a reconstructed image of the examinee at any phase of the periodic motion on a basis of data of the X-ray dose and data of the periodic motion; and a display device that displays the reconstructed image, characterized by comprising scanning condition calculating means that calculates a period of the periodic motion from the data of the periodic motion and calculates a scanning condition by using as an index a time resolution rate corresponding to a ratio between a time resolution of the reconstructed image and the period of the periodic motion of the examinee.