Patent ID: 7756241

Claim:
An X-ray computed tomography apparatus comprising: an X-ray tube that irradiates a subject with X-rays; an X-ray detecting unit that detects the X-rays irradiated from the X-ray tube and passed through the subject; an electrocardiograph that acquires an electrocardiographic waveform of the subject; an image reconstructing unit that reconstructs a tomographic image of a heart of the subject, based on X-ray detection information detected by the X-ray detecting unit and the electrocardiographic waveform of the subject acquired by the electrocardiograph; a characteristic-wave detecting unit that detects a predetermined characteristic wave from the electrocardiographic waveform acquired from the electrocardiograph; an X-ray irradiation control unit that determines an X-ray detection information collecting period during which the X-ray detection information is collected, based on an appearance interval of the predetermined characteristic wave detected by the characteristic-wave detecting unit; an input unit that receives an instruction to start collection of the X-ray detection information; a heartbeat determining unit that performs heartbeat determination whether an appearance interval of the predetermined characteristic wave detected by the characteristic-wave detecting unit is a normal heartbeat or an abnormal heartbeat, after a point of time at which the input unit receives the instruction to start the collection; and a control unit that controls the X-ray irradiation control unit such that the X-ray irradiation control unit recalculates and determines the X-ray detection information collecting period, when the heartbeat determining unit determines that an appearance interval is an abnormal heartbeat, during after the input unit receives the instruction to start the collection until reaching a time of starting the collection of the X-ray detection information determined by the X-ray irradiation control unit.