PET device and method of acquiring gamma ray generation position using scattered coincidence with PET device
AssigneeHamamatsu Photonics K.K.
InventorsMitsuo Watanabe, Takahiro Moriya, Tomohide Omura
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Abstract
A PET device includes detectors including detector signal processing units and a data processing circuit configured to acquire a gamma ray generation position. The detector signal processing unit includes a Compton cone estimating unit configured to estimate incidence directions of gamma rays detected by a pair of detectors as a first and second Compton cones. The data processing unit includes: a coincidence acquiring unit; a scattering surface estimating unit; an intersection line determining unit; an intersection point determining unit; and a gamma ray generation position.
Claims11
A method of acquiring a gamma ray generation position using scattered coincidence with a positron emission tomography (PET) device, the method comprising:
- detecting gamma rays using a pair of detectors arranged on a periphery of a subject, the subject being interposed between the pair of detectors;
- estimating incidence directions of gamma rays detected by the pair of detectors as first and second Compton cones;
- acquiring coincidence information of the gamma rays detected by the pair of detectors;
- estimating a scattering surface of the gamma rays on the basis of energy information of the gamma rays and a measurement line of the coincidence based on the coincidence information;
- determining presence/absence of an intersection line at which surfaces of the first and second Compton cones overlap each other;
- determining presence/absence of an intersection point at which the intersection line and the scattering surface intersect each other, when the intersection line is present and none of the first and second Compton cones overlaps the measurement line of the coincidence;
- and
- calculating a measurement line of scattered coincidence on the basis of the intersection point and acquiring a gamma ray generation position on the basis of the measurement line of the scattered coincidence and TOF information of the gamma rays, when the intersection point is present.
A PET device comprising:
- detectors arranged on a periphery of a subject, each of the detectors including a signal processing unit, and the subject being interposed between a pair of detectors in the detectors;
- a data processing unit configured to acquire a gamma ray generation position on the basis of information detected by the detectors,
- wherein the signal processing unit includes a Compton cone estimating unit configured to estimate incidence directions of gamma rays incident on the pair of detectors as first and second Compton cones, and
- wherein the data processing unit includes:
- a coincidence acquiring unit configured to acquire coincidence information of the gamma rays detected by the pair of detectors;
- a scattering surface estimating unit configured to estimate a scattering surface of the gamma rays on the basis of energy information of the gamma rays and a measurement line of coincidence based on the coincidence information;
- an intersection line determining unit configured to determine presence/absence of an intersection line at which surfaces of the first and second Compton cones overlap each other;
- an intersection point determining unit configured to determine presence/absence of an intersection point at which the intersection line and the scattering surface intersect each other, when the intersection line is present and none of the first and second Compton cones overlaps the measurement line of the coincidence;
- a coincidence line calculating unit configured to calculate a measurement line of scattered coincidence on the basis of the intersection point when the intersection point is present;
- and
- a gamma ray generation position acquiring unit configured to acquire a gamma ray generation position using the scattered coincidence on the basis of the measurement line of the scattered coincidence and the TOF information of the gamma rays when the intersection point is present.
Dependencies are inferred from the claim text.