Scanographic methods in visualization of the blood vessels and skeleton.

Abstract

Now that surgical methods can be used to treat successfully lesions of the aorta and major blood vessels, it is of the utmost importance that the radiologist develop technics for visualization of the larger vessels of the body. When opaque material is injected into an artery, it diffuses with the blood and is rapidly carried away from the point of injection. If a single roentgenogram is made at the time of injection, one may obtain visualization of the opaque material, though usually in a rather limited area of the vessel. If one uses a device for rapidly changing cassettes, a more extended view is obtained, showing the opaque material filling the vessels more peripherally. This method is usually quite adequate if one is dealing with the aorta or its iliac branches, but in investigation of the arteries of the leg, even a 14 × 17-inch film is not large enough to cover all the area desired. It was thought that the problem might be solved by a single exposure, using a 14 × 36-inch cassette, but while the bones of the entire leg were shown, the area of the vessels visualized by the opaque medium was still limited. In a recent review of the subject, Rogoff discussed the various methods employed in angiography, presenting an excellent bibliography. He advocates a method using serial exposures on 14 × 36-inch films, and presents some excellent illustrations to exemplify this procedure. This, however, involves the use of a 14 × 36-inch Potter-Bucky diaphragm, which is not available in most departments and is a comparatively expensive item. We believe that scanographic methods will give accurate results with less expensive and more widely available equipment. It seems exceedingly important to visualize the circulation of the entire leg. One must get an accurate idea of the extent of the runoff in the popliteal branches before undertaking to remedy a femoral block. Little will be gained by bridging a block if the circulation below is inadequate. Astle and Wallace-Jones in 1953 described their method of femoral arteriography with the aid of a scanning device. Using their technic, we have consistently obtained excellent results. This method we now follow routinely and have even extended its use to other purposes. We believe simple scanographic equipment should be used more frequently and should be available in the x-ray departments of all hospitals where vascular surgery is being done. Closely following the suggestions of Astle and Wallace-Jones, we have devised several small pieces of equipment. These include a 10-inch cone to the end of which is fastened a piece of lead 1∕8 inch thick, with a narrow slit in it, 3 inches long and 1∕8 inch wide, and a small hand-operated winch having a metal crank with a shaft 1∕2 inch in diameter. A 14 × 36-inch cassette is used, loaded with two 14 × 17-inch films carefully butted end to end.