Method collection of calibration data in radiation tomography apparatus

An object of the present invention, even if the detector ring 12 is wide, there is provided a method of collecting calibration data in radiation tomography apparatus reliably calibration data can be collected. To achieve this object, in the method of collecting calibration data in radiation tomography apparatus according to the present invention, by moving the phantom 41 for irradiating the annihilation γ-ray pair so as to pass through the internal bore having a detector ring 12 while, and has a configuration to get the number of simultaneous events. By configuring in this manner, the width of the detector is not necessary to be more than the width of the ring 12 of the phantom 41, reliably calibrated data can be collected. Further, the detector ring 12 may be annihilation γ-ray pair I than with a uniform property regardless of the position regarded to have been irradiated to obtain calibration data more suitable for image artifact removal.