Pet device and imaging method therefor

A positron emission tomography (PET) device for imaging a plurality of probes comprising:

• a group of PET gamma ray detectors adapted to receive a pair of pair-annihilation gamma rays from a subject to be imaged, wherein the pair of pair-annihilation gamma rays are generated by a positron-electron pair annihilation, and wherein to the subject to be imaged both of a first probe and a PET probe are administered, the first probe having a nuclide that becomes an excited state of a daughter nuclide through beta decay and, following a positron emission by the beta decay emits a unique gamma ray during transition into a ground state of the daughter nuclide, and the PET probe having a positron emitting nuclide that mainly becomes a ground state of a daughter nuclide through beta decay,
• an energy-resolving gamma ray detector adapted to receive the unique gamma ray emitted by the first probe;
• and
• an imaging processor that receives both of a pair-annihilation detection signal supplied according to coincidence measurement with a pair of PET gamma ray detectors in the group of PET gamma ray detectors and a signal supplied by the energy-resolving gamma ray detector, wherein the imaging processor executes reconstruction of images for the pair-annihilation detection signal differently according to whether detection of the pair-annihilation gamma rays and detection of the unique gamma ray occurred within a predetermined time or not.

A method for imaging a plurality of probes in a positron emission tomography (PET) device comprising steps of:

• coincidence measurement using a group of PET gamma ray detectors for a pair of pair-annihilation gamma rays from a subject to be imaged, wherein the pair of pair-annihilation gamma rays have been generated by a positron-electron pair annihilation, and wherein to the subject to be imaged both of a first probe and a second probe were administered, the first probe having a nuclide that becomes an excited state of a daughter nuclide through beta decay and, following a positron emission by the beta decay, emits a unique gamma ray of a first energy during transition into a ground state of the daughter nuclide, and the second probe having a nuclide that becomes an excited state of a daughter nuclide through beta decay and, following a positron emission by the beta decay, emits a unique gamma ray of a second energy during transition into a ground state of the daughter nuclide,
• performing measurement using an energy-resolving gamma ray detector that is adapted to detect one of the unique gamma rays for resolving the first energy and the second energy, and
• imaging processing for receiving both of a pair-annihilation detection signal supplied according to the coincidence measurement with a pair of PET gamma ray detectors in the group of PET gamma ray detectors and a signal supplied by the energy-resolving gamma ray detector, and for executing reconstruction of images for the pair-annihilation detection signal differently according to whether an energy value of a unique gamma ray detected within a predetermined time of the detection of the pair-annihilation gamma rays corresponds to the first energy or the second energy.

A method for imaging a plurality of probes in a positron emission tomography (PET) device comprising steps of:

• coincidence measurement using a group of PET gamma ray detectors for a pair of pair-annihilation gamma rays from a subject to be imaged, wherein the pair of pair-annihilation gamma rays have been generated by a positron-electron pair annihilation, and wherein to the subject to be imaged both of a first probe and a PET probe were administered, the first probe having a nuclide that becomes an excited state of a daughter nuclide through beta decay and, following a positron emission by the beta decay, emits a unique gamma ray during transition into a ground state of the daughter nuclide, and the PET probe having a positron emitting nuclide that mainly becomes a ground state of a daughter nuclide through the beta decay;
• performing measurement using an energy-resolving gamma ray detector for the unique gamma ray emitted by the first probe;
• and
• imaging processing for receiving both of a pair-annihilation detection signal supplied according to the coincidence measurement with a pair of PET gamma ray detectors in the group of PET gamma ray detectors and a signal supplied by the energy-resolving gamma ray detector, and for executing reconstruction of images for the pair-annihilation detection signal differently according to whether detection of the pair-annihilation gamma rays and detection of the unique gamma ray occurred within a predetermined time or not.