This invention relates to medical diagnostic x-ray apparatus, particularly apparatus for performing angiography.
In angiography procedures it is frequently necessary to obtain simultaneous x-ray views of the blood vessels in two different directions, such as in the postero-anterior direction and in the lateral direction. Apparatus which permits postero-anterior views is shown in U.S. Ser. No. 202,094, filed by Stivender et al. on Oct. 31, 1980 now U.S. Pat. No. 4,358,856 and assigned to the owner of the present invention. That application is incorporated herein by reference in its entirety to explain the construction and operation of the L-U arm apparatus for taking such views.
Two approaches are currently used for taking simultaneous lateral views. In the first approach, an x-ray source hung from the ceiling is positioned on one side of the patient and a freestanding x-ray detection device is positioned on the other side of the patient. As is well known, the freestanding detector and its associated electrical cables prevent the physician from moving freely around the patient and can also interfere with the source or detector for taking postero-anterior views. Another deficiency of this apparatus is that the source and detector for lateral views must be aligned manually.
A second approach is shown in FIGS. 12 and 13, illustrating two prior art devices. In the device shown in FIG. 12, a single structural member 20 carries an x-ray source 22 and an electronic image intensifier 24 at its respective ends. Member 20 is supported by a brace 26 pivotally mounted to an overhead support 28 for rotating the pattern of radiation passing from source 22 to detector 24 about a vertical axis without disturbing the relative alignment of source and detector. In the embodiment shown in FIG. 13, source 22 and detector 24 are rigidly mounted to the respective ends of a rigid C-shaped member 30 received in a guide 32, which again is pivotally mounted to an overhead support 34. In this embodiment, member 30 can be rotated as before, or can be driven in either direction through guide 32 to rotate the pattern of x-rays passing between source 22 and detector 24 about the longitudinal axis of a patient.
The devices of FIGS. 12 and 13 seriously interfere with access to the patient by the physician, and when in motion can present a hazard to the patient and those working around the patient. Also, since in both prior art embodiments the mass of the x-ray tube and image intensifier is supported at a single point between them, support members 20 and 30 are prone to gravitational and inertial bending moments and oscillations which complicate the problem of aiming source 22 at detector 24. Furthermore, such devices can be disturbing to the patient, who is encircled by machinery. These structures also are difficult or impossible to move out of the way when they are not in use, as the entire assembly must be moved as a unit and cannot be retracted or collapsed to provide head room.