METHOD OF QUICK BACK PROJECTION FOR COMPUTED TOMOGRAPHY AND IMPROVED CT MACHINE EMPLOYING THE METHOD

Computer tomography employs quick back projection, allowing for example software based back projection in a minicomputer. From the line of sight absorption data which is normally taken for computed tomography, the apparatus generates additional data files of more limited resolution, the most limited resolution file has such resolution that software controlled back projection employed in the minicomputer can be completed in a period of time of one minute or less. Thereafter, the operator controls a cursor so that subsequent back projection, on files of higher resolution, employ only a subset of the available data to also limit the processing time.