In order to see the cerebral arteries as continuous stereoscopic views, a new device for serial rotatostereocineangiography has been devised. A rotating ring, USZ-30, which is a device for Xray fluoroscopy using television, was utilized as a gantry, in which an X-ray tube and an image intensifier were installed, resulting in the same rotating center as the ring. The gantry is manually rotated from the lateral to the contralateral (180°) position in about 1.8 seconds. Because of the difference in density of the skull in the anteroposterior versus lateral positions, an aluminum filter was designed to correct this difference. A polyethylene bucket, with the bottom removed, was used as the head supporting device to avoid a shadow on the film. In order to control the exposure during rotation, two microswitches were used along with a cycle counter to measure the speed. A 35 mm cine film analysis projector, Nac 350, was modified, so as to project the adjacent cine film frames simultaneously. An observer can view the pictures of the cine film stereoscopically, using an adjustable stereoviewer, constructed with an over-screen hood, which corrects the human pupillary distance with mirrors.
Using the Seldinger technique, 15 ml of contrast medium were injected into either the internal carotid, external carotid or vertebral artery while rotating the gantry manually. Exposures taken at five degree intervals using an Arritechno 35 mm cine camera at the speed of 20 frames per second provided adequate stereoscopic views of the cerebral circulation when adjacent cine frames were observed through the adjustable stereoviewer. The afferent and efferent lesion vessels, such as aneurysms, arteriovenous malformations, carotid cavernous fistula or vascular tumors, could be observed using this method.
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