Serial rotatostereography - A new diagnostic method

In the previous study using cine, a cine film stereoprojector showed the adjacent two frames of cine film simultaneously, such as frames 1 and 2, 2 and 3, 3 and 4, and so on, consecutively. Because some intracranial lesions require emergency surgery immediately after angiography, a real time display method of serial rotatostereography was necessary. In order to show the consecutive adjacent two frames of a video disc simultaneously, using the same method as with the cine stereoprojector, a video disc recorder (VDR) (VM-1000M) and two video memories (Image Σ) were required. This VDR has the ability of advancing, stopping, and reversing the display of memories. A control unit was manufactured in order to display these memories advancing and reversing continuously. As a result of this continuous semirotation stereo display, the anteroposterior projection was reversed, showing the posteroanterior view during ''reversing mode''. Thus a lead relay circuit was manufactured to prevent this phenomenon. Recording was done using a memory disc recorder (FOM 2200F), which has the ability of recording 10,000 frames per disc. Each frame can also be recorded on imaging film using O · X Multi Camera 400X. Finally, stereoscopic views of cerebral circulation, using a single injection of contrast media and rapid rotation of the gantry, were obtained using two cathode-ray tubes (CRTs) and a stereoviewer (Continuous Semi-rotation Classical Stereo Display Method). Stereoscopic views were also obtained using a single CRT, which displayed the images in a semirotating fashion similar to a oscillating fan head (Continuous Semi-rotation New Stereo Display Method). (J.P.N.)