Method and system for scatter correction in X-ray imaging
Approaches for deriving scatter information using inverse tracking of scattered X-rays is disclosed. In certain embodiments scattered rays are tracked from respective locations on a detector to a source of the X-ray radiation, as opposed to tracking schemes that proceed from the source to the detector. In one such approach, the inverse tracking is implemented using a density integrated volume that reduces the integration steps performed.
1. A method for estimating scatter, comprising:
generating an initial volume based on X-ray transmission from a source to a detector;
characterizing a plurality of voxels within the initial volume based on material type;
generating a density integrated volume based on the plurality of voxels; and
tracking one or more scattered X-rays beginning at the detector and proceeding toward the source to generate a scatter profile for a plurality of discrete locations on the detector.
2. The method of claim 1 , comprising:
correcting scatter in one or more reconstructed images using the scatter profile or a kernel based at least in part on the scatter profile.
3. The method of claim 1 , wherein the plurality of voxels are characterized based on material types comprising soft tissue, bone, air, and contrast agent.
4. The method of claim 1 , wherein characterizing the plurality of voxels comprises applying a segmentation algorithm, wherein the output of the segmentation algorithm corresponds to the different respective material types.
5. The method of claim 1 , wherein characterizing the plurality of voxels comprises comparing observed intensity values or differences to respective thresholds corresponding to the different respective material types.
6. The method of claim 1 , wherein each voxel of the density integrated volume represents density integration from the source to the respective voxel.
7. The method of claim 1 , comprising:
generating a scatter rejection kernel based on at least the scatter profile and a scatter grid geometry associated with the detector.
8. The method of claim 7 , comprising:
updating the scatter profile based on the scatter rejection kernel to generate a revised scatter profile.
9. An image processing system, comprising:
a memory storing one or more routines; and
a processing component configured to execute the one or more routines stored in the memory, wherein the one or more routines, when executed by the processing component:
characterize a plurality of voxels within an initial reconstructed volume based on material type;
generate a density integrated volume based on the plurality of voxels;
inversely track one or more scattered X-rays from a respective reception point to a respective transmission point to generate a scatter profile for a plurality of discrete locations on the detector; and
generate one or more scatter corrected images using the scatter profile or a kernel based at least in part upon the scatter profile.
10. The image processing system of claim 9 , wherein the one or more routines, when executed by the processing component:
generate the initial reconstructed volume based on X-ray transmission from a source comprising the respective transmission point to a detector comprising the respective reception point.
11. The image processing system of claim 9 , wherein the plurality of voxels are characterized based on material types corresponding to a plurality of materials observed in medical images.
12. The image processing system of claim 9 , wherein characterizing the plurality of voxels comprises applying a segmentation algorithm, wherein the output of the segmentation algorithm corresponds to the different respective material types.
13. The image processing system of claim 9 , wherein characterizing the plurality of voxels comprises comparing observed intensity values or differences to respective thresholds corresponding to the different respective material types.
14. The image processing system of claim 9 , wherein each voxel of the density integrated volume represents the density integration from the respective transmission point to the respective voxel.
15. The image processing system of claim 9 , wherein the one or more routines, when executed by the processing component:
generate a scatter rejection kernel based on at least the scatter profile and a scatter grid geometry.
16. One or more non-transitory computer-readable media, encoding one or more routines which, when executed by a processor, cause the processor to perform acts comprising:
generating a density integrated volume, wherein each voxel of the density integrated volume represents the density integration from a source of X-rays to the respective voxel;
generating a scatter profile by tracking one or more scattered X-rays from respective locations on a detector to the source through the density integrated volume; and
correcting for scatter in one or more reconstructed images using the scatter profile or a kernel based at least in part upon the scatter profile.
17. The one or more non-transitory computer-readable media of claim 16 , wherein the density integrated volume is generated using an initial volume that has been characterized based on material type.
18. The one or more non-transitory computer-readable media of claim 17 , wherein the initial volume is characterized based on material type using a segmentation process or thresholding based on intensity values or intensity differences.
19. The one or more non-transitory computer-readable media of claim 16 , further encoding a routine which, when executed by a processor, causes the processor to perform the act of:
generating a scatter rejection kernel based on at least the scatter profile and a scatter grid geometry associated with the detector.
20. The one or more non-transitory computer-readable media of claim 16 , further encoding a routine which, when executed by a processor, causes the processor to perform the act of:
generating an initial volume based on X-ray transmission from the source to the detector.