Fiducial implant and system of such implants

• US 5,397,329 A
• Filed: 02/26/1993
• Issued: 03/14/1995
• Est. Priority Date: 11/10/1987
• Status: Expired due to Term

• Current Assignee: Marker
• Original Assignee: George S. Allen
• Inventors: Allen, George S.
• Primary Examiner(s): DeMille, Danton D.
• Application Number:
  US08/026,223
• Time in Patent Office: 746 Days
• Field of Search: 128/653, 606/72, 606/73, 606/60, 606/61, 606/130, 364/413.18, 364/413.22, 364/413.16, 364/413.13, 378/901, 382/6
• US Class Current: 378/205
• CPC Class Codes: A61B 2090/363 Use of fiducial points
• CPC Class Codes: A61B 2090/3954 magnetic, e.g. NMR or MRI
• CPC Class Codes: A61B 6/12 Arrangements for detecting or locating foreign bodies
• CPC Class Codes: A61B 90/10 for stereotaxic surgery, e.g. frame-based stereotaxis
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61N 5/1049 for verifying the position of the patient with respect to the radiation beam
• CPC Class Codes: Y10S 378/901 Computer tomography program or processor

Abstract

The present invention pertains to a fiducial implant for the human body that is detectable by an imaging system. The invention is comprised of a first portion and a second portion. The first portion is configured to be detected by an imaging system when placed beneath the skin. The second portion is configured for fixed attachment to a bone beneath the skin without penetrating entirely through the bone and without fracturing the bone. The first portion is sufficiently large and comprised of a material for detection by an imaging system, and sufficiently small to avoid the distortion of the skin when placed at an interface between the skin and the bone. The first portion also has at least a portion which is spherical and defines a surface for cooperating with a tool for securing the second portion to the bone. Additionally, the placement of three fiducial implants into a portion of anatomy of the human body allows for the recreation of a particular image slice of the portion of the anatomy taken by an imaging system with respect to a first time period, at subsequent imaging sessions and also with different scan modalities. This provides a doctor with the ability to accurately follow the progress of the portion of the anatomy of interest. Moreover, the existence of three fiducial implants allows a target to be identified within the portion of anatomy relative to an external coordinate system. The portion of anatomy with the target may then be operated on, for instance, robotically, or precisely irradiated.

Claims

1. A fiducial implant for the human body comprising:

a. a first portion substantially symmetrical in configuration and consisting of a material for detection by an imaging system when placed beneath the skin, said first portion also defining a hollow portion filled with a means for highlighting this portion of the implant to the imaging system;

b. said implant having a second portion including a screw having a length sufficiently long to secure the implant to the bone, but being configured so as not to penetrate the bone entirely and not to fracture the bone when attached thereto, wherein the second portion is dependent from said first portion;

c. said first portion being sufficiently small to provide minimal distortion of the skin when placed at an interface between the skin and the bone, and said screw is fully threaded into the bone; and

d. said screw having a length between 1 and 10 millimeters and said first portion having an effective diameter of between about 1 and 10 millimeters.

2. A fiducial implant for the human body comprising:

a. a first portion and a second portion, said first portion being made of titanium metal and configured to be detected by an imaging system, said first portion further being substantially spherical and hollow, with the hollow filled with agarose gel;

b. said second portion being made of titanium metal and configured for fixed attachment to a bone beneath the skin without penetrating entirely thorough the bone and without fracturing said bone;

c. said first portion being sufficiently large and comprised of a material for detection by an imaging system, and sufficiently small to provide minimal distortion of the skin when placed at the interface between the skin and the bone; and

d. said first portion having at least a portion which is spherical and defining a surface for cooperating with a tool for securing said second portion to the bone.

4. A fiducial implant according to claim 2, wherein the agarose gel has dopants which accent an image produced by the fiducial implant in an image imager.

3. A fiducial implant for the human body comprising:

a. a first portion substantially spherical and hollow in configuration, said hollow region containing agarose gel, and said first portion further consisting of a titanium material for detection by an imaging system when placed beneath the skin, said first portion also defining a recess having polygonal internal sides for engagement by an allen head tool;

b. said implant having a second portion made of titanium including a screw having a length sufficiently long to secure the implant to the bone, but being configured so as not to penetrate the bone entirely and not to fracture the bone when in place;

c. said sphere being sufficiently small to provide minimal distortion of the skin when placed at an interface between the skin and the bone.

5. A fiducial implant according to claim 3, wherein the agarose gel has dopants which accent an image produced by the fiducial implant in an image imager.

6. A fiducial implant for the human body comprising:

a. a first portion and a second portion, said first portion made of a bio-compatible material and being configured to be detected by an imaging system, said first portion further being substantially symmetrical and hollow, with the hollow filled with agarose gel;

b. said second portion being made of a bio-compatible material and being configured for fixed attachment to a bone beneath the skin without penetrating entirely thorough the bone and without fracturing said bone;

c. said first portion being sufficiently large and comprised of a material for detection by an imaging system, and sufficiently small to provide minimal distortion of the skin when placed at the interface between the skin and the bone; and

d. said first portion defining a surface for cooperating with a tool for securing said second portion to the bone.