Patent ID: 6175118
Filing Date: 2001-01-16
Classification: A61B,G01T

Abstract:
A gamma camera comprising:a camera head for detecting photons radiated from RIs administered to a human subject or from an external ray source;means for counting, out of the detected photons, those photons whose energy enters within a main window, the counted photon number being given as a first value;means for counting, out of the detected photons, those photons whose energy enters within a first sub-window arranged to a high energy side relative to the main window, the counted photon number being given as a second value, the first sub-window being centered to an energy corresponding to the number of photons of MAX/n in a standard energy spectrum wheren represents a rational number exceeding one,the standard energy spectrum represents an energy distribution of the photon number relating to direct rays from the RIs without scattering rays, andMAX represents a maximal photon number of the standard energy spectrum;means for counting, out of the detected photons, those photons whose energy enters within a second sub-window arranged to a low energy side relative to the main window, the counted photon number being given as a third value, the second sub-window being centered to an energy corresponding to the photon number of MAX/m in the standard energy spectrum wherem represents a rational number exceeding one, andmeans for correcting the first value on the basis of the second and third values.