MOTION ESTIMATION IN TREATMENT PLANNING

• US 20100054412A1
• Filed: 01/25/2008
• Published: 03/04/2010
• Est. Priority Date: 02/07/2007
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Gagnon, Daniel, Busch, Marc, Brinks, Ralph, Meyer, Carsten, Fischer, Alexander
• Granted Patent: US 8,351,571 B2
• Time in Patent Office: Days
• US Class Current: 378/65
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/721 using a separate sensor to detect motion or using motion information derived from signals other than the physiological signal to be measured
• CPC Class Codes: A61B 5/7289 Retrospective gating, i.e. associating measured signals or images with a physiological event after the actual measurement or image acquisition, e.g. by simultaneously recording an additional physiological signal during the measurement or image acquisition
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/037 Emission tomography
• CPC Class Codes: A61B 6/527 using data from a motion artifact sensor
• CPC Class Codes: A61N 2005/1052 using positron emission tomography [PET] single photon emission computer tomography [SPECT] imaging
• CPC Class Codes: A61N 5/103 Treatment planning systems
• CPC Class Codes: A61N 5/1037 taking into account the movement of the target, e.g. 4D-image based planning
• CPC Class Codes: A61N 5/1067 in real time, i.e. during treatment

Abstract

An apparatus includes a scanner (102, 104) and a scanning motion monitor (100). A motion modeler (116) uses data from the scanning motion monitor (100) and the scanner (102, 104) to generate a motion model which describes motion of a region of interest of an object. A treatment planner (112) uses image data from the scanner (102, 104) to establish a treatment plan for the object. A treatment device 114, which operates in conjunction with a treatment motion monitor (108), uses the motion model to compensate for motion of the object during application of the treatment.

Claims

1. A method comprising:

correlating projection data acquired during an examination of an object with a measured motion of the object;

using the correlated projection data to model a time varying feature of a first region of interest of the object;

supplying the model to a treatment apparatus that applies a treatment to the object.

2. The method of claim 1 including

measuring a motion of the object;

using the measured motion and the motion model to adjust an operation of the treatment apparatus.

4. The method of claim 1 wherein the motion is periodic and the method includes grouping the projection data according to a phase of the motion during which the projection data was acquired.

5. The method of claim 1 including filtering the correlated projection data to remove projection data which does not intersect the first region of interest, and wherein using the correlated projection data includes using the filtered correlated projection data to model the time varying feature.

6. The method of claim 1 including identifying a characteristic feature of the first region of interest and wherein the model models a motion of the characteristic feature.

8. The method of claim 1 including displaying a trajectory of the time varying feature in a human readable form.

9. The method of claim 1 including identifying a second region of interest which serves as a proxy for the motion of the first region of interest, wherein using includes using correlated projection data indicative of a characteristic feature of the second region of interest to model the motion of the first region of interest.

10. The method of claim 1 wherein the method includes

generating a motion corrected image of a region which includes the first region of interest;

prior to the step of using the correlated projection data to model a time varying feature of the first region of interest, using the motion corrected image to identify the first region of interest.

11. The method of claim 1 wherein the projection data includes list mode data indicative of radionuclide decays in the object.

3. (canceled)

7. (canceled)

12. (canceled)

13. An apparatus comprising:

a grouper (252) that groups projection data indicative of an interior of an object according to a motion of the object measured during the acquisition of the projection data;

a filter (254) that selects projection data that is indicative of a first region of interest of the object;

a characteristic processor (248) that uses the selected projection data to identify a characteristic feature of the first region of interest;

a position determiner (282) that determines a position of the identified feature as a function of the measured motion.

14. The apparatus of claim 13 including a hybrid modality scanner that generates the projection data.

15. The apparatus of claim 13 including a external radiotherapy apparatus (114) that modulates a therapy applied to the object as a function of the determined position and a motion of the object measured during the application of the therapy.

16. The apparatus of claim 13 wherein the measured motion is a physiological motion and the projection data includes time of flight positron emission tomography data.

18. The apparatus of claim 13 including means for displaying a motion of the identified feature.

17. (canceled)

19. (canceled)

20. A computer readable storage medium containing instructions which when executed by a computer cause the computer to carry out a method that includes:

grouping projection data indicative of radionuclide decays in an object according to a motion the object;

selecting projection data that is indicative of radionuclide decays occurring in a first region of interest of the object;

using the selected projection data to identify a characteristic feature of the first region of interest;

using the grouped projection data to determine a position of the identified feature as a function of the motion.

21. The computer readable storage medium of claim 20 wherein the determined position of the first region of interest serves as a proxy for a position of a second region of interest.

22. The computer readable storage medium of claim 20 wherein the method includes plotting a trajectory of the determined position on an image which includes the region of interest.

23. The computer readable storage medium of claim 20 wherein the method includes storing the determined position in a computer readable memory accessible to a treatment apparatus.

24. A method for correcting for motion in an image reconstructed from raw data, the method comprising:

identifying a first region of an object;

identifying a second region of the object;

using the raw data to estimate a characteristic feature of the first region;

using the estimated characteristic feature to correct raw data indicative of the second region to compensate for a motion of the second region;

using the corrected raw data to reconstruct a motion-corrected image of the second region.

25. The method of claim 24 wherein using the raw data includes

grouping the raw data into a plurality of temporal groups;

using the grouped raw data to perform locally constrained reconstructions of the first region.

26. The method of claim 24 wherein the raw data includes lines of response and using the raw data includes

determining spatial relationships between the lines of response;

using the determined spatial relationships to generate a point cloud.

27. The method of claim 24 wherein the method includes concurrently presenting an image of the second region and a motion of the estimated characteristic feature in human readable form.

28. The method of claim 24 wherein the raw data includes raw data representative of decays of a first radioactive tracer having an affinity for the first region and decays of a second, different tracer having an affinity for the second region.

29. The method of claim 24 including

correlating the raw data with a measured motion of the object;

using the correlated raw data to generate a motion model;

supplying the motion model to a treatment apparatus.

30. The method of claim 24 wherein the raw data includes lines of response representative of radionuclide decays and using the estimated characteristic feature includes

generating a motion model that models a motion of the characteristic feature;

identifying lines of response that intersect the second region;

using the motion model to vary a position of the identified lines of response.

31. The method of claim 24 wherein the raw data is list mode projection data.

32-39. -39. (canceled)

40. A method comprising:

using projection data acquired during an imaging examination of an object to estimate a characteristic feature of a region of interest of the object;

determining a trajectory of the characteristic feature;

presenting the determined trajectory in a human readable form.

41-43. -43. (canceled)