| 摘要 |
<p>Positron emission transaxial tomography apparatus comprises respective matrices 1 to 6 of detectors TPMij, as corresponding sides of a polygonal arrangement about an examination region, each matrix being associated with a corresponding photon conversion element CSi and optical coupling member GOi. The summed output from each detector matrix (1) is connected to a corresponding set of coincident circuits e.g. CCT13, CCT14, CCT15which are also connected to oppositely located detector matrices 3, 4, 5. If a coincidence is detected, the barycentre (linear) for the detector line array, is determined by a weighting circuit, not shown, from the detector signals after integration, to provide position data which is fed to an a-d converter, and the event is recorded in a memory. Any signal outside an energy window centered at 0.511 Mev is rejected. Tracer events are mapped as occurring on line paths across a sectional region, and the total numbers of events for each path, is stored in a memory M. The distribution of tracer throughout the body section is then computed. <IMAGE></p> |
