Reconstruction Stabilizer and Active Vision

• US 20090190807A1
• Filed: 07/19/2006
• Published: 07/30/2009
• Est. Priority Date: 07/19/2005
• Status: Active Grant

• Current Assignee: Spectrum Dynamics Medical Ltd
• Original Assignee: Spectrum Dynamics LLC
• Inventors: Rousso, Benny, Ben-Haim, Shlomo, Ziv, Omer, Dichterman, Eli
• Granted Patent: US 8,111,886 B2
• Time in Patent Office: Days
• US Class Current: 382/128
• CPC Class Codes: A61B 5/02755 Radioactive tracers
• CPC Class Codes: A61B 5/06 Devices, other than using radiation, for detecting or locating foreign bodies for removing same A61B17/50 ; determining position of probes within or on the body of the patient
• CPC Class Codes: A61B 5/415 the glands, e.g. tonsils, adenoids or thymus
• CPC Class Codes: A61B 5/418 lymph vessels, ducts or nodes
• CPC Class Codes: A61K 51/02 characterised by the carrier , i.e. characterised by the agent or material covalently linked or complexing the radioactive nucleus
• CPC Class Codes: A61K 51/04 Organic compounds
• CPC Class Codes: A61K 51/0402 carboxylic acid carriers, fatty acids amino acids A61K51/0406
• CPC Class Codes: A61K 51/0476 complexes from monodendate ligands, e.g. sestamibi
• CPC Class Codes: A61K 51/0478 complexes from non-cyclic ligands, e.g. EDTA, MAG3
• CPC Class Codes: A61K 51/048 DTPA (diethylenetriamine tetraacetic acid)
• CPC Class Codes: A61K 51/0489 Phosphates or phosphonates, e.g. bone-seeking phosphonates; phospholipids: A61K51/0408; nucleotides or nucleic acids: A61K51/0491
• CPC Class Codes: A61K 51/0491 Sugars, nucleosides, nucleotides, oligonucleotides, nucleic acids, e.g. DNA, RNA, nucleic acid aptamers
• CPC Class Codes: A61K 51/1203 in a form not provided for by groups A61K51/1206 - A61K51/1296, e.g. cells, cell fragments, viruses, virus capsides, ghosts, red blood cells, viral vectors

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.

21-95. -95. (canceled)