RESOURCE SHARING COMPUTER HIERARCHY FOR THREE-DIMENSIONAL X-RAY IMAGE RECONSTRUCTION OF THE HEART, LUNGS, AND CIRCULATION.

Future generation x-ray computed tomography scanners will be racterized by their ability to record simultaneously a sufficient number of x-ray projections to allow reconstructions of multiple adjacent cross sections of the object under study. An ability to repeat the entire data collection procedure with great rapidity, allowing many scan passes per second, should encourage research and diagnostic studies of moving organs such as the heart and lungs in truly three dimensions and in real time. The enormous amounts of data collected by such scanners will require major advances in associated computational hardware, with ultimate throughput capacities four to five orders of magnitude beyond the current state-of-the-art. A combined series of algorithmic, software, special-purpose computer architecture, and hardware implementation studies have demonstrated significant progress toward computed tomography reconstruction processing rates of 10**9 to 10**1**0 arithmetic operations per second.