Patent ID: 7688950

Claim:
An X-ray diagnostic apparatus, comprising: a tabletop configured to support a subject; an X-ray tube configured to irradiate X-rays and disposed on one side of the tabletop; an X-ray detector configured to detect X-rays that penetrate the subject and disposed on the other side of the tabletop; four diaphragm blade units located between the X-ray tube and the tabletop, a first pair of diaphragm blade units configured to move antithetically in a longer direction of the tabletop, and a second pair of diaphragm blade units configured to move antithetically in a shorter direction of the tabletop, each of the four diaphragm blade units configured to form an exposure field on the X-ray detector; a beam-limiting drive unit configured to drive each of the four diaphragm blade units individually; a center transfer control unit configured to indicate a moving destination at a center of the exposure field; a beam-limiting control unit configured to receive information about a moving amount and a moving direction when the center of the exposure field moves, to control the beam-limiting drive unit to move each of the four diaphragm blade units individually, and to form the exposure field of the moving center that is concentric therewith; and an operating information processing unit configured to calculate the moving amount and the moving direction of the center of the exposure field when receiving an indication from the center transfer operation unit and to output the calculated moving amount and moving direction of the center of the exposure field to the beam-limiting control unit.