Patent ID: 7490983

Claim:
An X-ray diagnostic apparatus comprising: a spoon shaped floor rotating arm provided at one end on a floor surface so as to be rotatable around a substantially vertical first rotation axis; a stand supported on the other end of the floor rotating arm so as to be rotatable around a substantially vertical second rotation axis; an arm holder supported on the stand so as to be rotatable around a substantially horizontal third rotation axis; a substantial C-arm supported on the arm holder so as to be slidable/rotatable around a substantially horizontal fourth rotation axis; an X-ray generating unit mounted inside the C-arm on one end of the C-arm; and an X-ray detecting unit mounted on the other end of the C-arm, wherein a distance from the first rotation axis to the second rotation axis is substantially equal to a distance from the second rotation axis to an isocenter where an imaging axis passing through an X-ray focal point of the X-ray generating unit and a detection surface center of the X-ray detecting unit, the third rotation axis, and the fourth rotation axis cross each other, wherein the stand is spoon shaped with a curvature retracted away from the substantially vertical first rotation axis, thereby permitting the arm holder supported on the stand to be retracted away from the substantially vertical first rotation axis, wherein a vertical thickness of said spoon shaped floor rotating arm decreases from a maximum vertical height to a constant minimum vertical height in a direction extending from said other end toward said one end, wherein the lowermost portion of said C-arm is located below the maximum vertical height of said spoon shaped floor rotating arm at said other end of said spoon shaped floor rotating arm, and wherein the one end of said floor rotating arm has the constant minimum vertical height over a portion with a certain length in a direction extending from the one end toward the other end, the certain length being sufficient that the X-ray generating unit mounted on one end of the C-arm and the X-ray detecting unit mounted on the other end of the C-arm are both entirely located directly over only the portion of the floor rotating arm having the constant minimum vertical height.