Attenuation map with scattered coincidences in Positron Emission Tomography

1. An imaging system, comprising:

a Positron Emission Tomography (PET) scanner which generates event data including true coincident events and scatter events, the event data includes each end point of a line of response (LOR) and an energy of each end point; and

one or more processors programmed to:

generate a plurality of activity map and attenuation map pairs based on the true coincident events; and

select an activity map and an attenuation map from the plurality of activity and attenuation map pairs based on the scattered events.

2. The imaging system according to claim 1 , wherein the one or more processors are further programmed to:

reconstruct an image based on the selected activity map.

3. The imaging system according to claim 1 , wherein the plurality of activity map and attenuation map pairs include similar distributions.

4. The imaging system according to claim 1 , wherein scattered events includes energy between 190 keV and 509 keV and a line or response (LOR) deflection angle greater than or equal to 4.2°.

5. An imaging system comprising:

a Positron Emission Tomography (PET) scanner configured to generate event data including true coincident events and scatter events, the event data including each end point of a line of response (LOR) and an energy of each end point; and

one or more processors programmed to:

generate a plurality of activity map and attenuation map pairs based on the true coincident events;

simulate a distribution of at least the scattered events based on each of the activity and attenuation map pairs; and

select the activity and attenuation map pair based on a comparison between the simulated distribution of scattered events and a recorded distribution of scattered events constructed from the recorded scattered events.

6. The imaging system according to claim 5 , wherein the one or more processors are further programmed to:

decompose a distribution of scattered events into attenuation components based on the end point location.

7. The imaging system according to claim 6 , wherein the decomposition includes voxels as a point source of activity.

8. The imaging system according to claim 5 , wherein the one or more processors are further programmed to:

reconstruct an image based on the true coincident events and the selected attenuation map.

9. The imaging system according to claim 5 , wherein the distribution of scattered events includes a computed angle of deflection.

10. The imaging system according to claim 5 , wherein the distribution of scattered events includes a frequency of occurrence of an offset of an angle of deflection.

11. A method of imaging, comprising:

receiving event data which includes true coincident events and scatter events, the event data includes each end point of a line of response (LOR) and an energy of each end point;

generating a plurality of activity map and attenuation map pairs based on the true coincident events; and

selecting an activity map and an attenuation map from the plurality of activity and attenuation map pairs based on the scattered events.

12. The method according to claim 11 , further including:

simulating a distribution of at least the scattered events based on each of the activity and attenuation map pairs; and

selecting the activity and attenuation map pair based on a comparison between the simulated distribution of scattered events and a recorded distribution scattered events constructed from the recorded scattered events.

13. A non-transitory computer-readable storage medium carrying software which controls one or more electronic data processing devices to perform a method according to claim 12 .

14. The method according to claim 11 , further including:

decomposing a distribution of scattered events into attenuation components based on the end point location.

15. The method according to claim 11 , further including:

reconstructing an image based on the true coincident events and the selected attenuation map.

16. The method according to claim 11 , further including:

reconstructing an image based on the selected activity map.

17. The method according to claim 11 , wherein the plurality of activity map and attenuation map pairs include similar distributions.

18. The method according to claim 11 , wherein a distribution of scattered events includes a computed angle of deflection.

19. An electronic data processing device configured to perform a method according to claim 11 .

20. An image processing system, comprising:

a list of positron emission tomography (PET) event data including a plurality of true coincident events and scattered coincident events, the scattered coincident events undergoing an angle of deflection greater than or equal to 4.2°, and the event data including end points and an energy of each event; and

one or more processors programmed to:

compute the angle of deflection for each scattered event;

simulate a distribution of the scattered events using the computed angles of deflection;

decompose the distribution of the scattered events into an attenuation map; and

reconstruct the true coincident events into an image based on using the attenuation map to correct for attenuation.