Radiation tomograph

An information processing apparatus mounted in a radiation tomograph including a detector ring for detecting an annihilation radiation pair derived from a radioactive drug distributed in a subject, the information processing apparatus comprising:

• occurrence position specifying means for specifying an occurrence position of annihilation radiation based on a time difference when an annihilation radiation pair enters the detector ring and an incident position of the annihilation radiation pair on the detector ring;
• data selecting means for selecting data on a pair generated in a vicinity of a surface of the subject from data indicating an occurrence position of radiation specified by the occurrence position specifying means;
• absorption characteristic distribution computing means for computing absorption characteristic distribution data indicating a distribution of absorption characteristics of annihilation radiation inside the subject by computing a level of decrease of the number of times of detection of one of a pair scattering in a direction of penetrating the subject due to absorption in the subject based on the number of times of detection of radiation scattering in a tangential direction of a curved surface forming the surface of the subject in an annihilation radiation pair derived from the vicinity of the surface of the subject based on selected data;
• and
• image generating means for generating an image indicating a radioactive drug distribution in the subject based on data indicating an occurrence position of radiation specified by the occurrence position specifying means,
• wherein the image generating means generates an image by executing absorption correction based on the absorption characteristic distribution data.

An information processing apparatus mounted in a radiation tomograph including a detector ring for detecting an annihilation radiation pair derived from a radioactive drug distributed in a subject and a radiation source configured to irradiate radiation from an outside of the subject and disposed inside the detector ring, the information processing apparatus comprising:

• occurrence position specifying means for specifying an occurrence position of annihilation radiation based on a time difference when an annihilation radiation pair enters the detector ring and an incident position of the annihilation radiation pair on the detector ring;
• data selecting means for selecting data on a pair generated by the radiation source from data indicating an occurrence position of radiation specified by the occurrence position specifying means;
• absorption characteristic distribution computing means for computing absorption characteristic distribution data indicating a distribution of absorption characteristics of annihilation radiation in the subject based on selected data;
• and
• image generating means for generating an image indicating a radioactive drug distribution in the subject based on data indicating an occurrence position of radiation specified by the occurrence position specifying means,
• wherein the image generating means generates an image by executing absorption correction based on the absorption characteristic distribution data.