Patent ID: 7912175

Claim:
An X-ray computed tomography (CT) apparatus comprising: an imaging unit for reconstructing an image on the basis of projection data obtained by scanning a subject in which a contrast agent is injected with an X ray; and a control unit for controlling the imaging unit, wherein the control unit comprises: a first control unit for performing a first monitoring scan in a first monitoring position to monitor an arrival of the contrast agent at a region of interest in a start position of a main scan in an imaging range of the main scan that is set along a body axis of the subject or the first monitoring position that is set before the start position in a scan progress direction and, on the arrival of the contrast agent, starting the main scan; and a second control unit for monitoring whether the contrast agent has reached the region of interest in a second monitoring position provided on the forward side of the start position of the main scan in the imaging range in the scan progress direction on arrival of the main scan at the second monitoring position, stopping the main scan and performing a second monitoring scan in the second monitoring position until the contrast agent reaches the second monitoring position, and restarting the main scan when the contrast agent reaches the second monitoring position, wherein the first monitoring scan and the second monitoring scan are performed with a dose that is lower than a dose with which the main scan is performed.