METHOD AND APPARATUS FOR POSITIONING AN OBJECT WITH RESPECT TO THE ISOCENTER OF AN ACQUISITION SYSTEM

• US 20080118037A1
• Filed: 01/25/2008
• Published: 05/22/2008
• Est. Priority Date: 11/28/2003
• Status: Active Grant

• Current Assignee: Stryker European Operations Holdings, LLC (Stryker Corporation)
• Original Assignee: General Electric Company
• Inventors: Pescatore, Jeremie
• Granted Patent: US 7,507,027 B2
• Time in Patent Office: Days
• US Class Current: 378/205
• CPC Class Codes: A61B 5/1127 using markers
• CPC Class Codes: A61B 6/08 Auxiliary means for directing the radiation beam to a particular spot, e.g. using light beams
• CPC Class Codes: A61B 6/547 involving tracking of position of the device or parts of the device

Abstract

Certain embodiments of the present invention relate to a system and method for object and isocenter alignment in an imaging system. The system includes an electromagnetic, an electromagnetic receiver, and an imaging unit for determining an isocenter of an imaging scanner based on information from the electromagnetic receiver. The imaging unit identifies the isocenter based on a plurality of electromagnetic position measurements. The imaging unit identifies a center of an object to be imaged based on information from a second electromagnetic receiver. The imaging unit repositions the object based on the isocenter. In an embodiment, the emitter is located on the object, the first receiver is located on a detector, and the second receiver is located on a tool for identifying a center of the object or a portion of the object.

Claims

1. A method for positioning an object at an isocenter of an imaging system, said method comprising:

acquiring two x-ray projections in an imaging system;

determining an isocenter for the imaging system based on the two x-ray projections;

locating a center position of an object to be imaged; and

positioning the center position of the object with respect to the isocenter.

2. The method of claim 1, wherein said determining step further comprises determining the isocenter based on a segment intersecting the x-ray projections.

3. The method of claim 1, wherein electromagnetic navigation devices are used to determine the isocenter and locate the center position.

4. The method of claim 1, wherein said aligning step further comprises at least one of manually and automatically moving the object to position the center position with respect to the isocenter.

5. A method for centering an object in an imaging system, said method comprising:

acquiring at least three position measurements for an electromagnetic receiver in an imaging system; and

computing an isocenter with respect to an electromagnetic emitter based on the at least three position measurements.

6. The method of claim 5, further comprising:

indicating a center position of an object; and

moving the object such that the isocenter and the center position are aligned.

7. The method of claim 5, wherein said moving step further comprises at least one of manually and automatically moving the object such that the isocenter and the center position match.

8. The method of claim 5, wherein said computing step further comprises computing the isocenter based on a center of the at least three position measurements.

9. A method for determining a working position for tomographic reconstruction, said method comprising:

calculating an approximate focal distance in an imaging system;

determining position and orientation information for an electromagnetic receiver with respect to an electromagnetic emitter in the imaging system; and

identifying an isocenter for the imaging system using the position and orientation information and approximate focal distance.

10. The method of claim 9, wherein said identifying step further comprises back-projecting the position information to identify the isocenter.

11. The method of claim 9, further comprising:

indicating a center position of an object around which a tomographic acquisition may be performed; and

moving the object such that the isocenter and the center position are aligned.

12. The method of claim 11, wherein said indicating step further comprises indicating the center position using a second electromagnetic receiver.

13. The method of claim 11, wherein said moving step further comprises at least one of automatically and manually moving the object such that the isocenter and the center position are aligned.