SYSTEMS AND METHODS FOR IMAGING LARGE FIELD-OF-VIEW OBJECTS

• US 20100142671A1
• Filed: 01/08/2010
• Published: 06/10/2010
• Est. Priority Date: 03/19/2002
• Status: Active Grant

• Current Assignee: Medtronic Navigation Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Navigation Incorporated (Medtronic Plc)
• Inventors: Gregerson, Eugene A., Grant, Richard K., Johnson, Norbert
• Granted Patent: US 8,678,647 B2
• Time in Patent Office: Days
• US Class Current: 378/19
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/06 Diaphragms
• CPC Class Codes: A61B 6/4021 involving movement of the focal spot
• CPC Class Codes: A61B 6/4085 Cone-beams
• CPC Class Codes: A61B 6/4233 using matrix detectors
• CPC Class Codes: A61B 6/4405 the apparatus being movable or portable, e.g. handheld or mounted on a trolley
• CPC Class Codes: A61B 6/4452 the source unit and the detector unit being able to move relative to each other
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 23/043 using fluoroscopic examination, with visual observation or video transmission of fluoroscopic images
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]

Abstract

An imaging apparatus and related method comprising a detector located a distance from a source and positioned to receive a beam of radiation in a trajectory; a detector positioner that translates the detector to an alternate position in a direction that is substantially normal to the trajectory; and a beam positioner that alters the trajectory of the radiation beam to direct the beam onto the detector located at the alternate position.

Claims

1. An imaging apparatus, comprising:

a detector located at a distance from a source and positioned to receive a radiation beam from the source in a trajectory;

a detector positioner that translates the detector, relative to a stationary focal spot of the source, to an alternate position in a direction that is substantially normal to the trajectory of the radiation beam; and

a beam positioner that alters the trajectory of the radiation beam to direct the beam onto the detector located at the alternate position.

2. The imaging apparatus of claim 1 wherein the detector is translated along an arc.

3. The imaging apparatus of claim 1 wherein the detector is translated along a line.

4. The imaging apparatus of claim 1 wherein the detector is a two-dimensional detector.

5. The imaging apparatus of claim 1 wherein the detector is a two-dimensional flat panel detector array.

6. The imaging apparatus of claim 1 wherein the source is an x-ray source.

7. The imaging apparatus of claim 1 wherein an object to be imaged is positioned in an imaging area between the source and the detector, the radiation beam from the source passing through a portion of the imaging area before being received at the detector.

8. The imaging apparatus of claim 7 wherein the object is more extensive than a field-of-view of the detector in at least one direction in which the detector is translatable.

9. The imaging apparatus of claim 1 wherein the detector positioner includes a positioner frame and a motor that translates the detector within the positioner frame.

10. The imaging apparatus of claim 1 wherein the beam positioner directs the radiation beam so that a central ray of the radiation beam remains directed at a geometric center of the detector while the detector translates.

11. The imaging apparatus of claim 1 wherein the beam positioner comprises a tilt system that tilts the source about its focal spot.

13. The method of claim 11 further including translating the detector along an arc.

14. The method of claim 11 further including translating the detector along a line.

15. The method of claim 11 wherein the detector is a two-dimensional detector.

16. The method of claim 11 wherein the detector is a two-dimensional flat panel detector array.

17. The method of claim 11 wherein the source is an x-ray source.

18. The method of claim 11 further including positioning an object to be imaged in an imaging area between the source and the detector, the radiation beam from the source passing through a portion of the imaging area before being received at the detector.

19. The method of claim 18 wherein the object is more extensive than a field-of-view of the detector in at least one direction in which the detector is translatable.

20. The method of claim 11 further including directing the radiation beam so that a central ray of the beam remains directed at a geometric center of the detector while the detector translates.

12. An method for imaging, comprising:

detecting a radiation beam, the radiation beam traveling in a trajectory from a source to a radiation detector;

translating the detector, relative to a stationary focal spot of the radiation source, to an alternate position in a direction that is substantially normal to the trajectory of the radiation beam; and

altering the trajectory of the radiation beam to direct the beam onto the detector located at the alternate position.

21. A detector system for imaging objects, the detector system comprising:

a gantry having an interior cavity;

a detector for detecting radiation from an object; and

a positioner frame movably mounted within the gantry that supports the detector and translates the detector within the interior cavity of the gantry.

22. The detector system of claim 21 wherein the positioner frame includes at least one rail that defines the translation path and bearings coupled with the at least one rail to guide the detector as it translates within the positioner frame.

23. The detector system of claim 22 further including a motor that drives a friction wheel against at least one rail on the positioner frame to translate the detector.

24. The detector system of claim 21 further including a positioning feedback system that indicates the position of the detector as it translates.

25. The detector system of claim 24 wherein the positioning feedback system includes a linear encoder tape and a read head.

26. The detector system of claim 24 wherein the positioning feedback system includes a rotary encoder and a friction wheel.

27. A system for projecting radiation in multiple trajectories, the system comprising:

a source that projects a radiation beam;

a frame that houses the source, the frame connected to the source so as to permit the source to pivotally move relative to the frame; and

a motorized system connected to the frame and to the source, the motorized system pivoting the source relative to the frame to alter trajectory of the radiation beam.

28. The system of claim 27 wherein the motorized system includes a linear actuator that controls the angle at which the source is pivoted relative to the frame.

29. The system of claim 28 wherein the source is pivoted about a focal spot of the beam of radiation.

30. The system of claim 27 wherein the source is an x-ray source.

31. An apparatus for imaging an object subjected to radiation doses, the object being larger than the field of view of a detector, comprising:

a radiation source;

a detector positioner that translates the detector, relative to a stationary focal spot of the radiation source, to different positions, the detector obtaining images at each position; and

a beam positioner that alters the trajectory of an imaging beam to follow a path to each position to produce safer dose utilization.