Patent ID: 7039227
Filing Date: 2006-05-02
Classification: A61B,G01T

Abstract:
1. A PET apparatus comprising: a detecting section which includes a plurality of cylindrical detectors each formed by two-dimensionally arraying a plurality of photon detection elements, each of which detects a photon flying from a measurement space including a central axis, on a cylinder surrounding the central axis, the plurality of cylindrical detectors being arrayed in a direction parallel to the central axis; a plurality of slice collimators which are alternately arranged with said cylindrical detectors at least between the measurement space and said detecting section in a direction parallel to the central axis, and pass only photons, of photons flying from the measurement space, which are substantially parallel to a predetermined plane perpendicular to the central axis toward said detecting section; a determining section which determines, when a pair of photon detection elements included in said detecting section simultaneously detect a photon pair, whether a straight line connecting light-receiving surfaces of the pair of photon detection elements crosses any one of said plurality of slice collimators; a first coincidence counting information accumulating section which accumulates coincidence counting information of the photon pair detected by the pair of photon detection elements when said determining section determines that the straight line crosses none of said plurality of slice collimators; a second coincidence counting information accumulating section which accumulates coincidence counting information of the photon pair detected by the pair of photon detection elements when said determining section determines that the straight line crosses one of said plurality of slice collimators; and an image reconstructing section which corrects an influence of a scattered component on the coincidence counting information accumulated by said first coincidence counting information accumulating section on the basis of the coincidence counting information accumulated by said second coincidence counting information accumulating section, and reconstructs an image representing a spatial distribution of occurrence frequencies of photon pairs in the measurement space on the basis of the corrected coincidence counting information.