System for determining target positions in the body observed in CT image data

• US 6,359,959 B1
• Filed: 06/01/1999
• Issued: 03/19/2002
• Est. Priority Date: 06/12/1992
• Status: Expired due to Fees

• Current Assignee: Integra Radionics, Inc. (Integra LifeSciences Holdings Corporation)
• Original Assignee: Sherwood Services AG
• Inventors: Butler, William E., Chapman, Paul H., Cosman, Eric R.
• Primary Examiner(s): Porta, David P.
• Application Number:
  US09/323,316
• Time in Patent Office: 1,022 Days
• Field of Search: 378/20, 378/62, 378/63, 378/162, 378/163, 378/164, 378/204, 378/205
• US Class Current: 378/20
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/702 Posture restraints
• CPC Class Codes: A61B 6/12 Arrangements for detecting or locating foreign bodies
• CPC Class Codes: A61B 6/501 for diagnosis of the head, e.g. neuroimaging or craniography

Abstract

This invention relates to the quantitative determination of a target or volume in the living body relative to external apparatus based on CT (computer tomography) or other image data. The invention describes a means of taking CT image data of the anatomy and of natural or implanted index positions on the patient'"'"'s body, and relating the CT data to a coordinate system related to external apparatus which may be in fixed position relative to the patient. One implementation uses a transformation between the CT image data coordinate system and the second coordinate system. This makes it possible to do frame-based or frameless stereotactic target identification and approaches without the need for attaching a frame to the patient at the time of CT scanning.

Claims

1. A method of relating the orientation of an external apparatus relative to patient'"'"'s anatomy as determined from computer tomographic (CT) image data, including:

(a) attaching to said patient'"'"'s anatomy detectable markers which are detectable in said CT image data to establish a coordinate reference frame relative to said patient'"'"'s anatomy, so that said detectable marker positions can be determined in said CT image data of said patient'"'"'s anatomy;

(b) taking images from at least one direction with a secondary imaging means, the orientation of said secondary imaging means being determinable relative to external apparatus, so as to detect said detectable markers and thereby determine the orientation of said patient'"'"'s anatomy as visualized in said CT image data relative to said external apparatus that is in a determined orientation relative to said secondary imaging means.

8. The method of claim 1 wherein said secondary imaging means comprises a computer tomographic imager.

9. The method of claim 1 wherein said secondary imaging means comprises an X-ray imager.

10. The method of claim 1 wherein said secondary imaging means comprises a magnetic resonance imager.

2. In connection with computer tomographic (CT) scanner and X-ray imaging apparatus, a system for relating external apparatus to patient'"'"'s anatomy as visualized from said CT scanner image data including:

(a) CT image detectable markers that can be attached to said patient'"'"'s anatomy and which can be visualized and thus related spatially in said CT scanner image data relative to said patient'"'"'s anatomy;

(b) external apparatus which can be located in a stable position near said patient'"'"'s anatomy, said external apparatus including reference structures attached to said external apparatus which can be seen in X-ray images from said X-ray imaging apparatus of said patient'"'"'s anatomy and said external apparatus, whereby upon X-ray imaging of said patient with said external apparatus nearby said patient, said reference structures and said detectable markers can be seen in said X-ray imaging, and thus the position of said external apparatus can be determined relative to said patient'"'"'s anatomy.

3. In connection with computer tomographic (CT) scanner and a secondary external imaging device, apparatus to relate the image data of said patient'"'"'s anatomy from said CT scanner to that of image data from said external imaging device, and thus to support means that is in a known orientation relative to said external imaging device and to said patient'"'"'s anatomy comprising:

(a) index means that can be fixed to said patient'"'"'s anatomy and that are detectable in said CT scanner image data and also are detectable in said external imaging device data, and thus the position of said index means relative to said patient'"'"'s anatomy can be determined in said CT scanner image data and said external imaging data;

(b) support means adapted to be held in a stable position relative to said patient'"'"'s anatomy and adapted so that the position of said support means can be determined relative to said external imaging device;

whereby when said support means is positioned relative to said patient'"'"'s anatomy and said external imaging device is positioned relative to said support means, image data from said external imaging device of said patient'"'"'s anatomy and of said index means can be used to determine the orientation of said support means to said patient'"'"'s anatomy as visualized by said CT scanner image data.

4. The apparatus of claim 3 wherein said support means is a rigid structure with radiopaque index means attached to it, and said external image device is an X-ray machine.

5. The apparatus of claim 4 wherein said index means are radiopaque point-like structures located in known positions relative to said support means.

6. The apparatus of claim 5 wherein said index means are radiopaque marks that can be attached in a fixed position relative to the bony structures of said patient'"'"'s anatomy.

7. The apparatus of claim 3 wherein said index means are detectable in an X-ray CT scanner or on magnetic resonance CT scanner so that comparative images from said scanners can be utilized.

11. The apparatus of claim 5 wherein said index means comprises radiopaque indices.