CT and MRI visible index markers for stereotactic localization

• US 6,419,680 B1
• Filed: 06/22/1995
• Issued: 07/16/2002
• Est. Priority Date: 06/10/1993
• Status: Expired due to Fees

• Current Assignee: Integra Radionics, Inc. (Integra LifeSciences Holdings Corporation)
• Original Assignee: Sherwood Services AG
• Inventors: Roberts, Theodore S., Cosman, Eric R.
• Primary Examiner(s): Smith, Ruth S.
• Application Number:
  US08/493,739
• Time in Patent Office: 2,581 Days
• Field of Search: 128/653.1, 128/653.2, 128/653.4, 128/653.5, 128/654, 378/162-164, 378/204, 378/205, 606/130, 600/414, 600/417, 600/426, 600/429
• US Class Current: 606/130
• CPC Class Codes: A61B 2034/207 Divots for calibration
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 2090/3954 magnetic, e.g. NMR or MRI
• CPC Class Codes: A61B 2090/3983 Reference marker arrangements for use with image guided surgery
• CPC Class Codes: A61B 2090/3995 Multi-modality markers
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: G06T 3/4061 by injecting details from different spectral ranges

Abstract

This invention relates to skin-based localizer markers that can be placed on the external anatomy of a patient during CT, MRI, or other scanning methods for producing identifiable index marks in stereotactic localization. In a preferred embodiment, the markers are of an annular or axially symmetric geometry, with provision for radiopaque and therefore CT-visible elements and also MRI-visible medium within the marker. The annular shape enables accurate identification of the centroid of the marker in the CT, MRI, or other tomographic image. Because the markers are visible in multi-modal imaging, such as CT and MR, registration of these images or stereotactic indexing can be done from one or both imaging types. In another embodiment, the marker has an index or concave central portion which enables a stereotactic digitized pointer to be placed stably within the indentation during calibration or marker identification in a surgical context. One application of the markers would be for cranial-based, frameless stereotaxy, where a stereotactic digitizing pointer can be used to pick off the positions of the markers in physical space so as to relate the physical space to two-dimensional or three-dimensional imaging data taken from CT or MR scanning.

Claims

1. A fiducial marker comprising:

a base;

a body structure connected to the base, the body structure configured and dimensional as an annular dome defining a sealed cavity therein;

an indented central depression being defined by the annular dome, the indented central depression defining an inwardly sloping top surface of the body structure and a central portion, the central portion being a bottom of the indented central depression and intersection of the sloping top surface, the central portion defining a stable positioning point, the stable positioning point being adapted for use with a tip of a stereotactic locating probe;

a first marker having an annular shape;

a second marker material disposed within the sealed cavity and being visible to image scanning, wherein the first marker is positioned in juxtaposition with the second marker and

a first centroid being defined by the first marker and a second centroid being defined by the second marker, wherein the first centroid and the second centroid are configured to be coincident, the stable positioning point being configured to be approximately coincident with the centroid of the first marker and the second marker.

2. The fiducial marker of claim 1, wherein the first marker is a radiopaque structure.

3. The fiducial marker of claim 1, wherein the base includes a flange.

4. The fiducial marker of claim 3, wherein the flange includes a self-sticking adhesive.