Method and system for using tissue-scattered coincidence photons for imaging

1. In an imaging system including a plurality of 3-D detectors, a method for determining a location of a photon event, the photon event producing a photon pair, the method comprising:

for one of the photons in the photon pair, detecting an interaction in a first 3-D detector, at least one photon of the photon pair being scattered prior to interacting with said plurality of 3-D detectors;

for the other of the photons in the photon pair, detecting at least two interactions in a second 3-D detector;

producing a cone-surface projector function based on the at least two interactions in the second 3-D detector;

producing a projector function based on said produced cone-surface projector function, the detected interaction in the first 3-D detector, and the at least two detected interactions in the second 3-D detector.

2. The method of claim 1 , wherein the at least two detected interactions in the second 3-D detector occur in 3-D space within the second 3-D detector.

3. The method of claim 1 , wherein the cone-surface projector function provides a set of locations for the photon event at which a probability is greater than zero.

4. The method of claim 1 , wherein each of the detected interaction in the first 3-D detector and the at least two detected interactions in the second detector provide an interaction location and energy.

5. The method of claim 1 , wherein the photon event is one of a plurality of photon events, and wherein the method further comprises:

for each of the plurality of photon events, producing a projector function, wherein a plurality of projector functions are produced;

generating an image based on the plurality of projector functions.

6. The method of claim 1 , wherein said produced projector function comprises a single scatter projector function, said single scatter projection function being based on the produced cone-surface projector function;

generating an image based on the produced single scatter projector function;

wherein the single scatter projector function is defined at least in part by a volume defined by the produced cone-surface projector function and by a volume enclosed by a single scatter surface.

7. The method of claim 6 , wherein the single scatter surface is produced using the detected interaction in the first 3-D detector and at least one of the detected interactions in the second 3-D detector.

8. An imaging system for performing the method of claim 1 .

9. An image generator configured to perform the method of claim 1 .

10. A computer-readable medium comprising computer-readable instructions that, when read, cause a computer to perform the method of claim 1 ;

wherein the computer comprises a processor and memory;

wherein said detecting an interaction from one photon in a pair in a first 3-D detector comprises the computer receiving signals from the first 3-D detector including an interaction location and energy and processing the received signals;

wherein said detecting the other photon in the pair produces at least two interactions in a second 3-D detector comprises the computer receiving signals from the second 3-D detector including at least two interaction locations and at least two energies; and

wherein the method further comprises:

generating an image from the detected interactions and the detected at least two interactions; and

displaying said generated image on an output device.

11. An imaging method comprising:

within a predetermined time window, receiving at least one signal from each of a pair of 3-D detectors, the signal indicating a photon interaction within the 3-D detector;

for each of the pair of 3-D detectors, determining a combined energy of the at least one signal;

if the combined energy for both of the pair of 3-D detectors is within a first energy window, generating a line projector function based on the received at least one signal from each of the pair of 3-D detectors;

if the combined energy is within a second energy window for one of the pair of 3-D detectors and within the first energy window for the other of the pair of 3-D detectors, generating a projector function based on the received at least one signal from each of the pair of 3-D detectors, wherein the received at least one signal comprises at least two signals from one of the pair of 3-D detectors;

wherein said generating a projector function comprises generating a cone-surface projector function based on the at least two signals from one of the pair of 3-D detectors and generating the projector function based on the generated cone-surface projector function and the received at least one signal from the pair of 3-D detectors.

12. A system for producing an image comprising:

a plurality of 3-D detectors disposed to receive emitted photons from a source, said plurality of 3-D detectors being configured to generate a signal in response to a photon interaction;

an image generator coupled to said plurality of 3-D detectors for producing an image based on the generated signal;

wherein, for an emitted pair of photons in coincidence in which one of the photons in the photon pair is scattered prior to interacting with the plurality of 3-D detectors, the emitted pair of photons generating an interaction signal in a first 3-D detector and at least two interaction signals in a second 3-D detector, said image generator is configured to produce a cone-surface projector function based on the at least two interaction signals in the second 3-D detector;

said image generator being further configured to produce a projector function based on the produced cone-surface projector function, the interaction signal from the first 3-D detector, and the at least two interaction signals in the second 3-D detector.

13. The system of claim 12 , wherein said plurality of 3-D detectors comprise cadmium-zinc-telluride (CZT) detectors.

14. The system of claim 13 , wherein said CZT detectors are disposed edge-on with respect to the source.

15. The system of claim 14 , further comprising:

a source of emitted photons.

16. The system of claim 12 , wherein said image generator comprises a computer.

17. The system of claim 12 , wherein said image generator is configured to produce a plurality of projector functions, and generate an image based on the plurality of projector functions.

18. A method for producing an image using a single-scatter coincidence photon event, the single-scatter coincidence photon event producing a pair of photons, the method comprising:

for each of the photons in the photon pair, detecting at least one interaction in a 3-D detector, each of the interactions providing a 3-D position and energy;

for at least one of the photons in the photon pair, detecting an additional interaction in the 3-D detector providing a 3-D position and energy;

based on the detected interaction for both of the photons and the detected additional interaction, producing the image;

wherein said producing the image comprises:

determining that the single-scatter coincidence photon event has occurred;

generating a cone-surface projector function based on the provided 3-D position and energy for the interaction and the additional interaction for the at least one of the photons;

generating a projector function based on the generated cone-surface projector function and the at least one detected interaction for each of the photons in the photon pair.

19. A system for radiation-based imaging comprising:

a plurality of 3-D detectors disposed with respect to a source of emitted photons to receive the emitted photons and produce interactions;

an image generator coupled to said plurality of 3-D detectors to receive a position and energy for the produced interactions and reconstruct an image;

said image generator being configured to reconstruct an image using at least one single-scatter coincidence photon event.