Patent ID: 7718971

Claim:
A positron emission computer tomography (PET) imaging apparatus including a detector configured to detect gamma-rays emitted from a predetermined diagnosis portion of an object containing a radioactive isotope, and an image generation unit configured to generate an image of the radioactive isotope from the object based on the detected gamma-rays, the PET imaging apparatus further comprising: a direction calculating unit configured to acquire incident directions of the gamma rays to the detector based on the detected gamma-rays; a first counting unit configured to acquire first count values of the gamma rays for each detecting position of the detector and each incident direction in a first time period; a second counting unit configured to acquire second count values of the gamma rays for each detecting position of the detector and each incident direction in a second time period; and a judging unit configured to judge whether a movement of the object has occurred based on differences between the first count values and the second count values at respective detecting positions and incident directions.