| 摘要 |
<p>Apparatus for obtaining CT scans employs a rotating unit operative to produce a scanning pencil beam of X-ray radiant energy by use of a mechanical scanning device consisting of a first collimator which shapes radiation emitted from an X-ray source into a fan- shaped beam of X-rays, and a second collimator comprising a disc- shaped chopper wheel which is rotated through the fan-shaped beam. A single pencil beam is produced and caused to scan through an angle, sufficiently great to embrace a cross section of a body being examined, onto at least one elongate detector forming a portion of the rotating unit and located on the side of the body opposite to the X- ray source and mechanical scanning device. The system can also be used to generate its own localization images and to perform digital radiography on those images and, because of the relative rotation feature, can be employed in this mode of to obtain anterior-posterior, lateral or oblique images at any desired angle. <IMAGE></p> |
