Apparatus for calculating coordinate data of desired point in subject to be examined

• US 5,285,787 A
• Filed: 09/29/1992
• Issued: 02/15/1994
• Est. Priority Date: 09/12/1989
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Machida, Yoshio
• Primary Examiner(s): Smith, Ruth S.
• Application Number:
  US07/953,760
• Time in Patent Office: 504 Days
• Field of Search: 128/653.1, 128/653.2, 128/653.5, 606/130, 378/205
• US Class Current: 600/417
• CPC Class Codes: A61B 2017/00712 simulating mathematical properties, e.g. for testing of positioning in the isocentre or focus
• CPC Class Codes: A61B 2017/00725 Calibration or performance testing
• CPC Class Codes: A61B 2090/3954 magnetic, e.g. NMR or MRI
• CPC Class Codes: A61B 90/10 for stereotaxic surgery, e.g. frame-based stereotaxis
• CPC Class Codes: G01R 33/58 Calibration of imaging systems, e.g. using test probes , Phantoms; Calibration objects or fiducial markers such as active or passive RF coils surrounding an MR active material

Abstract

A method of calculating coordinate data of a desired point in a subject to be examined is disclosed. A phantom image is obtained by integrally photographing a second frame, a frame coordinate phantom, and a second indicator phantom by using a computed tomographic apparatus. A subject image is then obtained by integrally photographing a first frame, the subject, and a first indicator phantom at the same position assumed when the phantom image is photographed. Coordinate data is obtained by correcting the deviation between the coordinates of the subject on the real space and the coordinates of the subject on the image photographed by the computed tomographic apparatus.

Claims

1. An apparatus for calculating coordinate data of a desired point in a subject comprising:

a frame for detachably holding the subject therein;

an indicator phantom affixed outside said frame;

a frame coordinate phantom being detachably mounted within said frame in place of said subject;

magnetic resonance imaging means for imaging said frame with said subject and said indicator phantom to produce a first image, and for imaging said frame with said frame coordinate phantom and said indicator phantom to produce a second image; and

calculating means for calculating the coordinate data of the desired point in the subject based upon said first image and said second image.

2. The apparatus of claim 1 wherein said frame coordinate phantom has marking means to display at least one axis of X, Y and Z.

3. The apparatus of claim 1 wherein said indicator phantom comprises marking means to display the coordinates of at least one axis of X, Y and Z coordinates in said first and second images.

4. The apparatus of claim 1 wherein said calculating means further comprising means for locating an image of said indicator phantom in said first image and an image of said indicator phantom in said second image, for obtaining a transformation formula between said image of said first indicator phantom in said first and second images, and for calculating a position in said subject based upon said transformation formula and a position in said frame coordinate phantom.

5. An apparatus for calculating coordinate data of a desired point in a subject comprising:

a first frame for holding the subject therein;

a first indicator phantom affixed outside said first frame;

a second frame having geometrically the same shape as that of said first frame;

a second indicator phantom affixed outside said second frame;

a frame coordinate phantom affixed inside said second frame;

magnetic resonance imaging means for imaging by magnetic resonance said first frame with said subject and said first indicator phantom to produce a first image, and for imaging said second frame with said frame coordinate phantom and said second indicator phantom to produce a second image; and

calculating means for calculating the coordinate data of the desired point in the subject based upon said first image and said second image.

6. The apparatus of claim 5 wherein said frame coordinate phantom has marking means to display at least one axis of X, Y and Z.

7. The apparatus of claim 5 wherein said first and second indicator phantoms each comprises marking means to display the coordinates of at least one axis of X, Y and Z coordinates in said first and second images.

8. The apparatus of claim 5 wherein said calculating means further comprising means for locating an image of said first indicator phantom and said second indicator phantom, for obtaining a transformation formula between said image of said first indicator phantom and said second indicator phantom, and for calculating a position in said subject based upon said transformation formula and a position in said frame coordinate phantom.