Patent ID: 8744039

Claim:
An X-ray CT apparatus for applying X-ray around an examinee, detecting a dose of X-ray transmitted through the examinee, reconstructing a tomogram of the examinee on the basis of the detected X-ray dose and outputting the tomogram characterized by comprising: a cross-section model generator that generates a cross-sectional model of the examinee by using scanogram projection data of the examinee; an input unit that inputs a desired image quality index value, a position of a site of interest, and an estimated displacement amount of the site of interest in a direction of a body axis during imaging; a scan planning unit that sets an irradiation X-ray dose modulating pattern corresponding to the desired image quality index value, the position of the site of interest and the estimated displacement amount input by the input unit by using the cross-section model generated by the cross-section model generating unit and by considering the estimated displacement amount of the site of interest during imaging; and an X-ray controller that modulates an irradiating X-ray dose on the basis of the irradiation X-ray dose modulating pattern set by the scan planning unit.