Patent ID: 7113569

Claim:
An X-ray CT apparatus, comprising: an X-ray irradiation source configured to irradiate X-rays to a volume of interest; an X-ray detector including a plurality of detection element segments configured to detect the X-rays penetrated through the volume of interest; a collimator configured to create an opening that is movable at least in a slice direction and a channel direction; an image processing part configured to generate volume data from the detected X-rays and to extract a portion of the volume data corresponding to the volume of interest; a controller configured to set the opening of the collimator to a first opening size to irradiate a first scanning range and configured to perform a first scan of the first scanning range, and to set the opening of the collimator in the channel direction to a second opening size to irradiate a second scanning range corresponding to the portion of the volume data and configured to perform a second scan of the second scanning range such that the second scanning range receives an amount of X-ray greater than an area external to the second scanning range; and a reconstruction part configured to reconstruct image data based on data collected by the second scan including data from the second scanning range and external data from an area within the first scanning range but external to the second scanning range.