RECONSTRUCTION STABILIZER AND ACTIVE VISION

• US 20120106820A1
• Filed: 01/09/2012
• Published: 05/03/2012
• Est. Priority Date: 07/19/2005
• Status: Active Grant

• Current Assignee: Spectrum Dynamics Medical Ltd
• Original Assignee: Spectrum Dynamics LLC
• Inventors: ROUSSO, Benny, Dichterman, Eli, Ziv, Omer, Ben-Haim, Shlomo
• Granted Patent: US 8,837,793 B2
• Time in Patent Office: Days
• US Class Current: 382/132
• CPC Class Codes: A61B 6/4258 for detecting non x-ray radiation, e.g. gamma radiation A61B6/037 takes precedence
• CPC Class Codes: G06T 11/006 Inverse problem, transformation from projection-space into object-space, e.g. transform methods, back-projection, algebraic methods
• CPC Class Codes: G06T 2211/412 Dynamic
• CPC Class Codes: G06T 2211/424 Iterative

Abstract

A method for stabilizing the reconstruction of an imaged volume is presented. The method includes the steps of performing an analysis of the reliability of reconstruction of a radioactive-emission density distribution of the volume from radiation detected over a specified set of views, and defining modifications to the reconstruction process and/or data collection process to improve the reliability of reconstruction, in accordance with the analysis.

Claims

1. A method for stabilizing the reconstruction of an imaged volume, comprising:

performing an analysis of the reliability of reconstruction of a radioactive-emission density distribution of said volume from radiation detected over a specified set of views; and

defining modifications to at least one of a reconstruction process and a data collection process to improve said reliability of reconstruction, in accordance with said analysis.

2. A method according to claim 1, further comprising calculating a measure of said reliability of reconstruction, said measure of reliability of reconstruction being for determining a necessity of performing said modifications.

3. A method according to claim 1, further comprising:

providing a detection probability matrix defining a respective detection probability distribution of said volume for each of said views;

calculating the singular values of said detection probability matrix;

identifying singular values as destabilizing singular values.

4. A method according to claim 3, further comprising performing singular value decomposition (SVD) of said probability matrix.

5. A method according to claim 3, wherein said identifying comprises:

for each of said singular values, calculating a respective ratio of said singular value to a largest singular value; and

specifying a singular value having a respective ratio below a specified threshold as destabilizing.

6. A method according to claim 3, further comprising calculating a condition number of said probability matrix as a measure of said reliability of reconstruction.

7. A method according to claim 6, further comprising performing said identifying if said condition number exceeds a specified magnitude.

8. A method according to claim 3, wherein said modification comprises defining constraints on said reconstruction process to reduce an effect of said destabilizing singular values upon a reconstruction of said volume.

9. A method according to claim 3, further comprising identifying, for a destabilizing singular value, an associated unreliable voxel of said reconstructed volume.

10. A method according to claim 3, further comprising identifying, for a destabilizing singular value, an associated unreliable linear combination of voxels of a reconstruction of said volume.

11. A method according to claim 1, wherein said modification comprises smoothing a selected portion of said volume during said reconstruction.

12. A method according to claim 1, wherein said modification comprises uniting multiple voxels of said volume into a single element of said reconstruction.

13. A method according to claim 1, wherein said modification comprises defining views for imaging said volume.

14. A method according to claim 13, wherein said defining is performed to obtain a required resolution.

15. A method according to claim 13, wherein said defining comprises specifying multiple scan densities for imaging said volume.

16. A method according to claim 15, wherein each of said scan densities is for a different respective portion of said volume.

17. A method according to claim 13, wherein said defining is performed dynamically during radioactive-emission measurements of said volume.

18. A method according to claim 13, further comprising performing radioactive-emission measurements of the body structure, at a predetermined set of views;

and wherein said modification comprises dynamically-defined views for continued imaging of said volume.

19. A method according to claim 9, wherein said modification comprises defining a non-uniform scan for data collection.

20. The method of claim 1, further comprising providing at least one intensity distribution, wherein an intensity distribution comprises a representation of a radioactive-emission density distribution of said volume.