Motion tracking system for real time adaptive imaging and spectroscopy

• US 9,138,175 B2
• Filed: 04/28/2015
• Issued: 09/22/2015
• Est. Priority Date: 05/19/2006
• Status: Active Grant

• Current Assignee: Medical College of Wisconsin Incorporated, Queen's Medical Center, Research Corporation of The University of Hawaii, UWM Research Foundation
• Original Assignee: Medical College of Wisconsin Incorporated, Queen's Medical Center, Research Corporation of The University of Hawaii, UWM Research Foundation
• Inventors: Ernst, Thomas Michael, Prieto, Thomas Edmund, Armstrong, Brian Stewart Randall
• Primary Examiner(s): Seth, Manav
• Application Number:
  US14/698,350
• Publication Number:
  US 20150227793A1
• Time in Patent Office: 147 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0077 Devices for viewing the surface of the body, e.g. camera, magnifying lens
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/1127 using markers
• CPC Class Codes: A61B 5/1128 using image analysis A61B5/1127 takes precedence
• 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 5/7292 Prospective gating, i.e. predicting the occurrence of a physiological event for use as a synchronisation signal
• CPC Class Codes: A61B 6/0492 using markers or indicia for aiding patient positioning
• CPC Class Codes: A61B 6/547 involving tracking of position of the device or parts of the device
• CPC Class Codes: G01R 33/28 Details of apparatus provided for in groups G01R33/44 - G01R33/64
• CPC Class Codes: G01R 33/56509 due to motion, displacement or flow, e.g. gradient moment nulling G01R33/567 takes precedence
• CPC Class Codes: G06T 7/0012 Biomedical image inspection
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: G06V 10/62 relating to a temporal dimension, e.g. time-based feature extraction; Pattern tracking
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

This invention relates to a system that adaptively compensates for subject motion in real-time in an imaging system. An object orientation marker (30), preferably a retro-grate reflector (RGR), is placed on the head or other body organ of interest of a patient (P) during a scan, such as an MRI scan. The marker (30) makes it possible to measure the six degrees of freedom (x, y, and z-translations, and pitch, yaw, and roll), or “pose”, required to track motion of the organ of interest. A detector, preferably a camera (40), observes the marker (30) and continuously extracts its pose. The pose from the camera (40) is sent to the scanner (120) via an RGR processing computer (50) and a scanner control and processing computer (100), allowing for continuous correction of scan planes and position (in real-time) for motion of the patient (P). This invention also provides for internal calibration and for co-registration over time of the scanner'"'"'s and tracking system'"'"'s reference frames to compensate for drift and other inaccuracies that may arise over time.

Claims

1. A magnetic resonance image recording and tracking system for use during a magnetic resonance examination by a magnetic resonance scanner, comprising:

a wall of a scanner bore of a magnetic resonance magnet;

a receiving area that is at least enclosed partially by the wall;

a small camera positioned on or in the wall of the scanner bore, the small camera configured to periodically image a marker in the receiving area; and

a tracking system configured to analyze images generated by the small camera to determine changes in position of the marker, and to generate tracking data for use by the magnetic resonance scanner to dynamically adjust scans to compensate for the changes in position of the marker.

2. The magnetic resonance image recording and tracking system of claim 1, further comprising a second camera positioned on or in the wall of the scanner bore, the second camera configured to periodically image the marker in the receiving area.

3. The magnetic resonance image recording and tracking system of claim 2, wherein the second camera is configured to continuously image a second marker in the receiving area.

4. The magnetic resonance image recording and tracking system of claim 2, wherein the small camera and the second camera are each configured to view the marker along a different line of sight.

5. The magnetic resonance image recording and tracking system of claim 1, wherein the small camera is configured to continuously image the marker in the receiving area.

6. The magnetic resonance image recording and tracking system of claim 1, wherein the marker is an object orientation marker.

7. The magnetic resonance image recording and tracking system of claim 6, wherein the object orientation marker is configured to indicate orientation in six degrees of freedom.

8. The magnetic resonance image recording and tracking system of claim 6, wherein the object orientation marker is a retro-grate reflector marker.

9. The magnetic resonance image recording and tracking system of claim 1, wherein the tracking system comprises a computer processor and an electronic memory.

10. The magnetic resonance image recording and tracking system of claim 1, wherein the small camera is shielded to avoid interference with the magnetic resonance scanner.

11. A magnetic resonance image recording and tracking system for use during a magnetic resonance examination by a magnetic resonance scanner, comprising:

a detector configured for positioning on or in a wall of a scanner bore of a magnetic resonance magnet, the wall at least partially enclosing a receiving area that is configured to receive a subject for scanning by the magnetic resonance scanner, the detector configured to image a marker coupled to the subject in the receiving area; and

a tracking system configured to analyze images generated by the detector to determine changes in position of the marker, and to generate tracking data for use by the magnetic resonance scanner to dynamically adjust scans to compensate for the changes in position of the marker,

wherein the tracking system comprises a computer processor and electronic memory.

12. The magnetic resonance image recording and tracking system of claim 11, wherein the detector comprises a camera.

13. The magnetic resonance image recording and tracking system of claim 11, wherein the detector comprises at least two detectors, the at least two detectors each configured to view the marker along a different line of sight.

14. The magnetic resonance image recording and tracking system of claim 11, wherein the detector is configured to continuously image the marker in the receiving area.

15. The magnetic resonance image recording and tracking system of claim 11, wherein the marker is an object orientation marker.

16. The magnetic resonance image recording and tracking system of claim 15, wherein the object orientation marker is configured to indicate orientation in six degrees of freedom.

17. The magnetic resonance image recording and tracking system of claim 15, wherein the object orientation marker is a retro-grate reflector marker.

18. The magnetic resonance image recording and tracking system of claim 11, wherein the detector is shielded to avoid interference with the magnetic resonance scanner.

19. The magnetic resonance image recording and tracking system of claim 11, wherein the detector is configured to directly image the marker coupled to the subject in the receiving area.

20. The magnetic resonance image recording and tracking system of claim 11, further comprising at least one mirror, wherein the detector is configured to indirectly image through the mirror the marker coupled to the subject in the receiving area.

21. A magnetic resonance image recording and tracking system for use during a magnetic resonance examination by a magnetic resonance scanner, comprising:

a wall of a scanner bore of a magnetic resonance magnet;

a receiving area that is at least enclosed partially by the wall;

a camera positioned in the wall of the scanner bore, the camera configured to periodically image a marker in the receiving area; and

a tracking system configured to analyze images generated by the camera to determine changes in position of the marker, and to generate tracking data for use by the magnetic resonance scanner to dynamically adjust scans to compensate for the changes in position of the marker,

the tracking system comprises a computer processor and electronic memory.

22. The magnetic resonance image recording and tracking system of claim 21, further comprising a second camera positioned in the wall of the scanner bore, the second camera configured to periodically image the marker in the receiving area.

23. The magnetic resonance image recording and tracking system of claim 22, wherein the second camera is configured to continuously image a second marker in the receiving area.

24. The magnetic resonance image recording and tracking system of claim 22, wherein each of the cameras are configured to view the marker along a different line of sight.

25. The magnetic resonance image recording and tracking system of claim 21, wherein the camera is configured to continuously image the marker in the receiving area.

26. The magnetic resonance image recording and tracking system of claim 21, wherein the marker is an object orientation marker.

27. The magnetic resonance image recording and tracking system of claim 26, wherein the object orientation marker is configured to indicate orientation in six degrees of freedom.

28. The magnetic resonance image recording and tracking system of claim 26, wherein the object orientation marker is a retro-grate reflector marker.

29. The magnetic resonance image recording and tracking system of claim 21, wherein the camera is shielded to avoid interference with the magnetic resonance scanner.

30. The magnetic resonance image recording and tracking system of claim 21, wherein the camera is configured to directly image the marker in the receiving area.

31. The magnetic resonance image recording and tracking system of claim 21, further comprising at least one mirror, wherein the camera is configured to indirectly image through the mirror the marker in the receiving area.