GAMMA CAMERA, SPECT DEVICE, PET DEVICE AND GAMMA-RAY MEASUREMENT IMAGE GENERATION METHOD

摘要

PROBLEM TO BE SOLVED: To make a gamma-ray measurement image brighter by appropriately estimating and removing a noise amount caused by a scattered gamma ray.SOLUTION: An energy-window-specific count image generation unit 33 generates a main measurement count image and a secondary measurement count image on the basis of energy of a gamma ray 6 measured by a detector head 10 and count information; a spectrum storage unit 31 stores an energy spectrum at the time of unscattered incidence of the gamma ray 6 as detector response data; a secondary measurement window scattered line count amount estimation unit 41 estimates a count amount of a scattered gamma ray at a secondary measurement energy window on the basis of the secondary measurement count image and the detector response data; and a main measurement window direct delivery line count amount estimation unit 42 estimates a count amount of a scattered gamma ray at a main measurement energy window on the basis of the estimated count amount of the scattered gamma ray at the secondary measurement energy window, and estimates a count amount of a directly-delivered gamma ray at the main measurement energy window by deducting the estimated count amount of the scattered gamma ray from the main measurement count image.