Stereotactic surgery apparatus and method

• US 4,341,220 A
• Filed: 04/13/1979
• Issued: 07/27/1982
• Est. Priority Date: 04/13/1979
• Status: Expired due to Term

• Current Assignee: Sherwood Services AG
• Original Assignee: Pfizer Inc.
• Inventors: Perry, John H.
• Primary Examiner(s): Michell, Robert W.
• Assistant Examiner(s): Kruter, J. L.
• Application Number:
  US06/029,865
• Time in Patent Office: 1,201 Days
• Field of Search: 128/303 B, 128/630, 128/653, 128/659, 128/660, 250/312, 250/445 T, 250/491, 250/476, 269/322, 33/174 D, 33/174 J
• US Class Current: 606/130
• CPC Class Codes: A61B 90/11 with guides for needles or instruments, e.g. arcuate slides or ball joints
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers

Abstract

X-ray detectable fiducial markers are associated with a stereotactic surgery frame. The frame is fixed with respect to a patient'"'"'s anatomy and defines a predetermined three-dimensional coordinate system in which surgical devices may be precisely positioned. A desired target area of the anatomy is detected in a cross-sectional CT scanner depiction of the combined stereotactic frame and patient anatomy. The target'"'"'s coordinates with respect to the frame are calculated based on three non-collinear fiducial points also located within the cross-section and having known coordinates both with respect to the frame and with respect to the target.

In the exemplary embodiment, detachable fiducial point-defining members are associated with a stereotactic surgical frame. For example, each member may be a plate having a series of parallel grooves or slots which progressively increase in length from one slot to the next. The frame coordinates of the end points of each slot are predetermined and known. Thus three fiducial points with respect to the frame can be determined by simply counting the number of slots or grooves contained within the cross-sectional depiction and thereby determining which end point is within such cross-section.

Claims

1. Stereotactic frame apparatus adapted for use in performing stereotactic surgery with an X-ray CT scanner, said stereotactic frame apparatus comprising:

a stereotactic frame defining a three-dimensional coordinate system which can be fixed with respect to the anatomy of a living patient,

said stereotactic frame including mechanism for positioning a desired surgical device within said anatomy at any desired location defined in terms of said three-dimensional coordinate system, and

X-ray detectable fiducial marker means associated with said stereotactic frame defining at least three non-collinear points within each planar cross-section therethrough, said marker means including means for determining the three-dimensional coordinates of said three points in each said cross-section whereby a scan in any single plane provides the three-dimensional coordinates of said three noncollinear points.

2. Apparatus as in claim 1 wherein said X-ray detectable fiducial markers comprise:

a member having an X-ray detectable feature which intersects any said cross-section at a location which varies depending upon the relative disposition of the cross-section.

3. An improved stereotactic surgery frame of the type defining a three-dimensional coordinate system which can be fixed with respect to the anatomy of a living patient and which can thereafter position a desired surgical device within such anatomy at any desired location defined in terms of said three-dimensional coordinate system, said improvement comprising:

X-ray detectable fiducial markers physically associated with said frame and defining at least three measurable noncollinear fiducial points, each having predetermined visually determinable three-dimensional coordinates within a single cross-sectional depiction taken through the combination of said anatomy and of said frame and its associated fiducial markers.

4. An improvement as in claim 3 wherein said fiducial markers comprise:

a plate having a variable cross-section extending a predetermined distance with respect to a first dimension, said predetermined distance varying with respect to a second dimension which is inclined with respect to said first dimension.

5. An improvement as in claim 3 wherein said fiducial markers comprise:

a member having a detectable feature which intersects any desired cross-sectional depiction at a location which varies depending upon the relative disposition of the cross-section.

6. An improvement as in any one of claim 3-5 wherein said fiducial markers are removably attachable to said stereotactic frame.

7. A method to facilitate stereotactic surgery, said method comprising the steps of:

fixing a stereotactic surgical frame, having a first predetermined three-dimensional coordinate system, with respect to living tissue,

scanning the combination of said frame and living tissue with penetrating radiation to provide a cross-sectional depiction thereof in a single plane which includes a desired anatomical target within said living tissue,

determining the three-dimensional coordinates of said target with respect to a second predetermined three-dimensional coordinate system,

determining the three-dimensional coordinates of each of at least three non-collinear points located within said cross-sectional depiction in a single plane, both with respect to the three-dimensional coordinate system of said frame and with respect to said second three-dimensional coordinate system, and

using said determined coordinates to calculate the coordinates of said target with respect to the three-dimensional coordinate system of said frame.

8. A method as in claim 7 wherein said scanning step is performed with an X-ray CT scanner.

9. A method as in claim 7 wherein said fixing step includes the attachment of X-ray detectable fiducial markers to said frame.

10. A method as in claim 7 wherein said second-mentioned determining step includes counting detectable features associated with said frame at predetermined relative locations and present in said cross-sectional depiction.

11. A method as in claim 7 wherein said second-mentioned determining step includes measurement of relative distances between detectable features associated with said frame at predetermined relative locations and present in said cross-sectional depiction.

12. Apparatus for performing three-dimensional stereotactic surgery within the anatomy of a living patient, said apparatus comprising:

a tomographic scanner having a programmable data processing computer, a CRT display for depicting the relative densities of elemental volumes with a desired planar cross-sectional slice of matter appropriately placed within the CT scanner, and an operator console for entering data and/or instructions into said computer and for identifying the location and relative positional coordinates of any desired element or portion of said slice;

a rigid frame fixably securable with respect to said anatomy and defining a multi-dimensional coordinate system in which surgical devices can be precisely positioned;

said frame including plural detectable features which if included as a portion of a single said slice of matter in a single plane, will be represented in said depiction of said cross-sectional slice as a respectively corresponding set of at least three functional points in the plane having predetermined known or readily determinable three-dimensional frame coordinates; and

said computer being programmed to compute the three-dimensional frame coordinates of any desired anatomical target depicted within said slice as a function of the frame coordinates of said fiducial points and of the relative positional coordinates of said target and said fiducial points within said CRT display.

13. Apparatus as in claim 12 wherein said rigid frame includes at least one detectable feature disposed along a path connecting dissimilar portions of similar spaced-apart frame structures.

14. Apparatus as in claim 12 or 13 wherein said rigid frame includes an inclined rod connected between dissimilar portions of two spaced-apart parallel posts.

15. A method to facilitate stereotactic surgery, said method comprising the steps of:

fixing a stereotactic surgical frame, having a first predetermined multi-dimensional coordinate system, with respect to living tissue,

scanning the combination of said frame and living tissue with penetrating radiation to provide a cross-sectional depiction thereof in a single plane which includes a desired anatomical target within said living tissue,

determining the three-dimensional coordinates of said target with respect to a second predetermined multi-dimensional coordinate system,

determining the three-dimensional coordinates of each of plural points located within said cross-sectional depiction, both with respect to the first multi-dimensional coordinate system of said frame and with respect to said second multi-dimensional coordinate system, and

using said determined three-dimensional coordinates to calculate the three-dimensional coordinates of said target with respect to the multi-dimensional coordinate system of said frame.

16. A method as in claim 15 wherein said scanning step is performed with an x-ray CT scanner.

17. A method as in claim 15 wherein said fixing step includes the attachment of x-ray detectable fiducial markers to said frame.

18. A method as in claim 15 wherein said determining step includes counting detectable features associates with said frame at predetermined relative locations and present in said cross-sectional depiction.

19. A method as in claim 15 wherein said determining step includes measurement of relative distances between detectable features associated with said frame at predetermined relative location and present in said cross-sectional depiction.

20. An improved stereotactic surgery frame of the type defining a multi-dimensional coordinate system which can be fixed with respect to the anatomy of a living patient and which can thereafter position a desired surgical device within such anatomy at any desired location defined in terms of said multi-dimensional coordinate system, said improvement comprising:

fiducial markers physically associated with said frame and defining at least three unique non-collinear measurable fiducial points having determinable three-dimensional coordinates with respect to said frame with a single planar cross-sectional depiction taken through the combination of said anatomy and of said frame and its associated fiducial markers.

21. Apparatus for use in performing stereotactic surgery, said apparatus comprising:

an X-ray CT scanner capable of measuring relative X-ray absorption within elemental volumes of a desired planar cross-section of the anatomy of a living patient and which CT scanner also defines a first multi-dimensional CT scanner coordinate system relative to its own geometrical structure for locating specific anatomical positions with said planar cross-section relative to said first coordinate system,

a stereotactic frame defining a second multi-dimensional coordinate system which can be fixed with respect to the anatomy of a living patient,

said stereotactic frame including mechanism for positioning a desired surgical device within said anatomy at any desired location defined in terms of said second multi-dimensional coordinate system, and

X-ray detectable fiducial markers associated with said stereotactic frame defining plural points within each of said planar cross-sections, each point having determinable coordinates in both said first and said second coordinate systems

said CT scanner including means for transforming the measured CT scan coordinates in three dimensions of a desired portion of the anatomy to corresponding three-dimensional coordinates in said second coordinate system thereby facilitating the use of said stereotactic frame during stereotactic surgery.

22. An improved stereotactic surgery frame of the type defining a three-dimensional coordinate system which can be fixed with respect to the anatomy of a living patient and which can thereafter position a desired surgical device within such anatomy at any desired location defined in terms of said three-dimensional coordinate system, said improvement comprising:

fiducial markers physically associated with said frame and defining at least three measurable non-collinear fiducial points within a cross-sectional depiction taken through the combination of said anatomy and of said frame and its associated fiducial markers.

said fiducial markers including a plate having a variable cross-section extending a predetermined distance with respect to a first dimension, said predetermined distance varying with respect to a second dimension which is inclined with respect to said first dimension, and

said plate having a series of parallel elongated structures with different respective lengths.

24. An improvement as in claim 22 or 23 wherein said parallel elongated structures are regularly spaced and of substantially equal dimensions and wherein said respective lengths progressively increase or decrease from one structure to the next.

25. An improvement as in any of claims 22 or 23 comprising a plurality of said plates each being adapted for physical attachment to a respectively corresponding portion of said stereotactic frame.

23. An improved stereotactic surgery frame of the type defining a three-dimensional coordinate system which can be fixed with respect to the anatomy of a living patient and which can thereafter position a desired surgical device within such anatomy at any desired location defined in terms of said three-dimensional coordinate system, said improvement comprising:

fiducial markers physically associated with said frame and defining at least three measurable non-collinear fiducial points within a cross-sectional depiction in a plane taken through the combination of said anatomy and of said frame and its associated fiducial markers,

said fiducial markers including a member having an X-ray detectable feature which intersects any desired cross-sectional depiction at a location which varies depending upon the relative disposition of the cross-section, and

said member comprising a plate having a series of parallel elongated structures with different respective lengths.

26. Apparatus for performing three-dimensional stereotactic surgery within the anatomy of a living patient, said apparatus comprising:

a tomographic scanner having a programmable data processing computer, a CRT display for depicting of the relative densities of elemental volumes within a desired planar cross-sectional slice of matter appropriately placed with the CT scanner, and an operator console for entering data and instructions into said computer and for identifying the location and relative positional coordinates of any desired element or portion of said slice;

a rigid frame fixably securable with respect to said anatomy and defining a multi-dimensional coordinate system in which surgical devices can be precisely positioned;

said frame including plural detectable features which, if included as a portion of said matter, will be represented in said depiction of said planar cross-sectional slice as respectively corresponding plural fiducial points having predetermined known or readily determinable frame coordinates;

and

said computer being programmed to compute the frame coordinates of any desired anatomical target depicted within said slice as a function of the frame coordinates of said fiducial points and of the relative positional coordinates of said target and said fiducial points with said CRT display,

said rigid frame including three fiducial plates, each having a plurality of parallel elongated structures of varying length.

27. Stereotactic frame apparatus adapted for use in performing stereotactic surgery, said apparatus comprising:

an X-ray CT scanner means capable of measuring relative X-ray absorption within elemental volumes of a desired cross-section of the anatomy of a living patient and which CT scanner means defines a first three-dimensional CT scanner coordinate system relative to its own geometrical structure for locating specific anatomical positions within said cross-section relative to said first coordinate system,

a stereotactic frame defining a second three-dimensional coordinate system which can be fixed with respect to the anatomy of a living patient,

said stereotactic frame including mechanism for positioning a desired surgical device within said anatomy at any desired location defined in terms of said second three-dimensional coordinate system, and

X-ray detectable fiducial markers associated with said stereotactic frame defining at least three non-collinear points within each of said cross-sections, each point having determinable coordinates in both said first and said second coordinate systems such that the measured CT scan coordinates of a desired portion of the anatomy can be transformed to corresponding coordinates in said second coordinate system thereby facilitating the use of said stereotactic frame during stereotactic surgery,

each of said X-ray detectable fiducial markers comprising a member having a series of parallel elongated structures therein with different respective lengths and interacting any said cross-section at a location which varies depending upon the relative disposition of the cross-section.

28. Apparatus as in claim 27 wherein said parallel elongated structures are regularly spaced and of substantially equal dimensions and wherein said respective lengths progressively increase or decrease from one slot to the next.

29. Apparatus as in claim 27 or 28 comprising a plurality of said members each being adapted for physical attachment to a respectively corresponding portion of said stereotactic frame.

30. Apparatus as in claim 27 or 28 wherein said X-ray detectable fiducial markers are removably attachable to said stereotactic frame.

31. Stereotactic frame apparatus adapted for use in performing stereotactic surgery, said apparatus comprising

an X-ray CT scanner means capable of measuring relative X-ray absorption within elemental volumes of a desired cross-section of the anatomy of a living patient and which CT scanner means defines a first three-dimensional CT scanner coordinate system relative to its own geometrical structure for locating specific anatomical positions within said cross-section relative to said first coordinate system,

a stereotactic frame defining a second three-dimensional coordinate system which can be fixed with respect to the anatomy of a living patient,

said stereotactic frame including mechanism for positioning a desired surgical device within said anatomy at any desired location defined in terms of said second three-dimensional coordinate system,

X-ray detectable fiducial markers associated with said stereotactic frame defining at least three non-collinear points within each of said cross-sections, each point having determinable coordinates in both said first and said second coordinate systems such that the measured CT scan coordinates of a desired portion of the anatomy can be transformed to corresponding coordinates in said second coordinate system thereby facilitating the use of said stereotactic frame during stereotactic surgery,

said frame including spaced-apart posts;

and

said markers including a rod extending between dissimilar portions of pairs of said spaced-apart posts.