Positron emission tomography (pet) imaging using scattered and unscattered photons

A method for forming a Positron Emission Tomography (PET) image, the method comprising:

• for a plurality of scattering coincident events, the event characterized by a full-energy photon detected at a first detector and partial-energy photon detected at a second detector;
• detecting the scatter coincidence event,
• measuring the energy of the partial-energy photon;
• determining a scattering point as a function of at least:
• the position of the first detector, the position of the second detector,
• the measured energy of the partial-energy photon,
• the expected energy of an unscattered photon,
• the mass of a scattering electron,
• and the speed of light;
• determining a pseudo-Line-Of-Response (LOR) defined by the scattering point and the position of the first detector;
• forming an image from:
• a plurality of pseudo-LOR, and a plurality of LOR determined from a true coincidence events.

A method for forming a Positron Emission Tomography (PET) image, the method comprising:

• detecting a scatter coincidence event, the event characterized by a full-energy photon detected at a first detector and partial-energy photon detected at a second detector;
• and
• for a plurality of scattering coincident events, the event characterized by a full-energy photon detected at a first detector and partial-energy photon detected at a second detector;
• detecting the scatter coincidence event,
• measuring the energy of the partial-energy photon;
• measuring the time difference between the time of arrival of the partial energy photon at the second detector and the time of arrival of the full energy photon at the first detector;
• determining a scattering point as a function of at least:
• the position of the first detector, the position of the second detector,
• the measured energy of the partial-energy photon,
• the expected energy of an unscattered photon,
• the mass of a scattering electron,
• and the speed of light;
• determining the position of a radioactive PET source along a line between the scatter point and the first detector as a function of at least:
• for each determined position of a radioactive PET source within a predetermined boundary, determining a pseudo-Line-Of-Response (LOR) defined by the scattering point and the position of the first detector;
• forming an image from:
• a plurality of pseudo-LOR, and a plurality of LOR determined from a true coincidence events.

A Positron Emission Tomography (PET) system comprising:

• a plurality of detectors;
• a PET data processing system;
• and
• program code for:
• detecting a scatter coincidence event, the event characterized by a full-energy photon detected at a first detector and partial-energy photon detected at a second detector;
• and
• measuring the time difference between the time of arrival of the partial energy photon at the second detector and the time of arrival of the full energy photon at the first detector;
• measuring the energy of the partial-energy photon;
• determining a scattering point as a function of at least:
• the position of the first detector, the position of the second detector,
• the measured energy of the partial-energy photon,
• the expected energy of an unscattered photon,
• the mass of a scattering electron,
• and the speed of light;
• and
• determining the position of a radioactive PET source along a line between the scatter point and the first detector as a function of at least:
• the distance between scatter point and the first detector,
• the distance between scatter point and the second detector, and
• the measured time difference.

A Positron Emission Tomography (PET) system comprising:

• a plurality of detectors;
• a PET data processing system;
• and
• program code for:
• for a plurality of scattering coincident events, the event characterized by a full-energy photon detected at a first detector and partial-energy photon detected at a second detector;
• detecting the scatter coincidence event,
• measuring the energy of the partial-energy photon;
• determining a scattering point as a function of at least:
• the position of the first detector, the position of the second detector,
• the measured energy of the partial-energy photon,
• the expected energy of an unscattered photon,
• the mass of a scattering, electron,
• and the speed of light;
• determining a pseudo-Line-Of-Response (LOR) defined by the scattering point and the position of the first detector;
• forming an image from a plurality of pseudo-LOR, and a plurality of LOR determined from a true coincidence events.

A Positron Emission Tomography (PET) system comprising:

• a plurality of detectors;
• a PET data processing system;
• and
• program code for:
• detecting a scatter coincidence event, the event characterized by a full-energy photon detected at a first detector and partial-energy photon detected at a second detector;
• and
• for a plurality of scattering coincident events, the event characterized by a full-energy photon detected at a first detector and partial-energy photon detected at a second detector;
• detecting the scatter coincidence event,
• measuring the energy of the partial-energy photon;
• measuring the time difference between the time of arrival of the partial energy photon at the second detector and the time of arrival of the full energy photon at the first detector;
• determining a scattering point as a function of at least:
• the position of the first detector, the position of the second detector,
• the measured energy of the partial-energy photon,
• the expected energy of an unscattered photon,
• the mass of a scattering electron,
• and the speed of light;
• determining the position of a radioactive PFT source along a line between the scatter point and the first detector as a function of at least:
• for each determined position of a radioactive PET source within a predetermined boundary, determining a pseudo-Line-Of-Response (LOR) defined by the scattering point and the position of the first detector;
• forming an image from:
• a plurality of pseudo-LOR, and a plurality of LOR determined from a true coincidence events.