| 摘要 |
<p>An imaging system is described which utilises pairs of gamma ray photons, the members of each pair travelling in mutually opposite directions. Position sensitive detection of the first of a photon pair allows determination of the direction of the second. This information is used in conjunction with information derived from back scattering of the second from the target volume permits generation of a two dimensional image of the density distribution within the target volume.</p> |
