Patent ID: 8842804

Claim:
An X-ray computed tomography apparatus, comprising: an X-ray tube configured to generate X-rays; a detector configured to detect X-rays which are generated from the X-ray tube and transmitted through a subject; a first support mechanism configured to rotatably support the X-ray tube and the detector; a first driving unit configured to drive the first support mechanism to rotate the X-ray tube and the detector around the subject; a top on which the subject is placed; a second support mechanism configured to movably support the top; a second driving unit configured to drive the second support mechanism to move the top; an acquisition unit configured to acquire projection data associated with the subject via the detector; a position determination unit configured to determine a position of the top at an estimated start time of projection data acquisition by the acquisition unit; a first angle determination unit configured to determine a first rotational angle of the X-ray tube at the estimated start time of projection data acquisition; a second angle determination unit configured to determine a second rotational angle of the X-ray tube at an estimated start time of movement of the top based on the determined first rotational angle and a time interval from the estimated start time of movement to the estimated start time of projection data acquisition; and a control unit configured to control the first driving unit to rotate the X-ray tube around the subject, control the second driving unit to make the top start moving in response to arrival of the X-ray tube at the determined second rotational angle, and control the acquisition unit to start acquiring projection data in response to arrival of the top at the determined position of the top.