Overview

In order to rea1ize real-time medica1 imaging systems, such as are used for computed tomography, automated miscroscopy, dynamic radioisotope imaging, etc., special techno1ogy is required. The high-speed image sour ce must be successfu11y married with the u1tra- high-speed computer. Usua11y the ordinary genera1-purpose computer is found to be inadequate to the image generation and/or image pro- cessing task. The ordinary computer executes instructions at be- tween 1 and 10 million per second. Speed has improved by only about a factor of 10 during the past 20 years. In contrast a typical com- puter used in recognizing blood cell images at 10,000 per hour must execute instructions at between 1 billion and 10 billion per second. Simi1ar execution rates are required to construct a computed tomogra- phy image in real-time (1 to 10 seconds). For the reasons given above, engineering development in image generation and processing in the field of biomedicine has become a discipline unto itself; a discipline wherein the computer engineer is driven to design extremely high-speed machines that far surpass the ordinary computer and the x-ray, radioisotope, or microscope scanner designer must also produce equipment whose specifications extend far beyond the state-of-the-art.