X-RAY DOSE ESTIMATION TECHNIQUE

• US 20140185751A1
• Filed: 12/28/2012
• Published: 07/03/2014
• Est. Priority Date: 12/28/2012
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: De Man, Bruno Kristiaan Bernard, Yin, Zhye, Tian, Xiaoyu
• Granted Patent: US 9,125,286 B2
• Time in Patent Office: Days
• US Class Current: 378/51
• CPC Class Codes: A61B 6/4035 the source being combined with a filter or grating
• CPC Class Codes: A61B 6/4241 using energy resolving detectors, e.g. photon counting
• CPC Class Codes: A61B 6/542 involving control of exposure
• CPC Class Codes: H05G 1/28 Measuring or recording actual exposure time; Counting number of exposures; Measuring required exposure time

Abstract

Embodiments of the disclosure relate to projection-based volumetric dose estimation for X-ray systems, such as X-ray imaging systems. For example, in one embodiment, an X-ray system is capable of estimating an X-ray dose based on an energy interaction of the X-rays with respective portions of an object. In another embodiment, the X-ray dose estimate may be provided on a per voxel, per region, and/or per organ basis.

Claims

1. A method, comprising:

using a processor;

receiving information generated by an X-ray detector related to detected X-rays of an X-ray beam that have passed through an object;

estimating a first energy interaction with a first portion of the object based on an intensity profile of the detected X-rays of the X-ray beam;

estimating a remaining energy in the X-ray beam after passing through the first portion of the object;

estimating a second energy interaction with a second portion of the object adjacent to the first portion of the object, wherein the X-ray beam passes through the first portion before the second portion, based on the remaining energy;

determining a first estimated dose value for the first portion based at least in part on the first energy interaction and the mass of the first portion of the object; and

determining a second estimated dose value for the second portion based at least in part on the second energy interaction and the mass of the second portion of the object.

2. The method of claim 1, comprising determining a total X-ray imaging energy for the portion of the object based on a sum including the first estimated dose value and the second estimated dose value and additional estimated dose values.

3. The method of claim 1, comprising estimating a third energy interaction with a third portion of the object based on a remaining energy of the X-ray beam after passing through the second portion of the object and determining a third estimated does value for the third portion based at least in part on the third energy interaction and the mass of the third portion of the object.

4. The method of claim 1, wherein the information generated by the X-ray detector comprises X-rays detected from a plurality of projection lines of the X-ray beam.

5. The method of claim 1, comprising determining an overlap coefficient between the X-ray beam and the first portion or the second portion.

6. The method of claim 1, wherein determining the first energy interaction comprises a sum of energy interaction for the first portion for the plurality of projection lines and determining the second energy interaction comprises a sum of energy interactions for the second portion for the plurality of projection lines.

7. The method of claim 1, comprising estimating the mass of the first portion and the second portion by estimating an average mass from a plurality of X-ray images.

8. The method of claim 1, comprising estimating the mass of the first portion and the second portion by correcting an estimated mass based on a correction factor.

9. The method of claim 1, wherein the first portion and the second portion comprise a first voxel and a second voxel adjacent to one another.

10. An X-ray system comprising:

an X-ray source configured to generate an X-ray beam through a plurality of projection lines;

a detector configured to detect X-rays of the X-ray beam that pass through an object for each respective projection line; and

a processor coupled to the detector and configured to receive information generated by the detector related to the detected X-rays, and wherein the processor is configured to execute instructions for;

dividing the object into a plurality of respective volumes;

determining an intensity profile of the detected X-rays that pass through each respective volume for each respective projection line;

determining an attenuation profile of the detected X-rays that pass through each respective volume for each respective projection line;

estimating an energy interaction for each respective volume based on the intensity profile for each respective projection line;

estimating a mass for each respective volume of the object based on at least one attenuation profile;

determining an estimated dose value for the object based at least in part on the energy interaction with each respective volume of the object for each respective projection line and the mass of each respective volume of the object.

11. The X-ray system of claim 10, wherein the estimated dose value for an individual volume comprises a sum of the respective estimated dose values for each respective projection line for the individual volume.

12. The X-ray system of claim 10, wherein the plurality of respective volumes comprise voxels.

13. The X-ray system of claim 10, wherein determining the intensity profile comprises estimating a remaining energy from the X-rays after exiting each respective volume.

14. The X-ray system of claim 10, wherein determining an estimated dose value for the object comprises summing the estimated dose values of the respective volumes of the object.

15. The X-ray system of claim 10, wherein determining an estimated dose value for the object comprises correcting each respective volume for a scatter effect across the entire object.

16. The X-ray system of claim 10, wherein determining an estimated dose value for the object comprises correcting each respective volume for a scatter effect in a voxel-dependent correction.

17. The X-ray system of claim 16, wherein the scatter effect is larger near edges of the object and wherein the correcting takes the edges into account.

18. An X-ray system, comprising:

a processor configured to receive information generated by an X-ray detector related to X-rays that have passed through an individual volume of an object, wherein the processor is configured to execute instructions for;

determining an intensity profile of the detected X-rays that pass through the volume of the object;

estimating an energy interaction with the volume of the object based on the intensity profile; and

determining a remaining energy in the X-ray beam after the energy interaction.

19. The X-ray system of claim 18, wherein the processor is configured to execute instructions for determining an estimated dose value for the volume of the object based at least in part on the energy interaction with the volume of the object and an estimated mass of the volume of the object.

20. The X-ray system of claim 18, comprising determining a second energy interaction for a second volume of the object based on the remaining energy.