Computerized boundary estimation in medical images

• US 5,820,559 A
• Filed: 03/20/1997
• Issued: 10/13/1998
• Est. Priority Date: 03/20/1997
• Status: Expired due to Fees

• Current Assignee: Ming Yeong Teo, Wan Sing Ng
• Original Assignee: Ming Yeong Teo, Wan Sing Ng
• Inventors: Teo, Ming Yeong, Ng, Wan Sing
• Primary Examiner(s): JAWORSKI, FRANCIS J
• Application Number:
  US08/821,641
• Time in Patent Office: 572 Days
• Field of Search: 606/15, 606/20-21, 606/39-41, 606/159, 606/169, 601/2, 601/3, 600/439, 600/443, 600/461-463, 600/470, 382/6
• US Class Current: 600/439
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/4209 by using holders, e.g. positioning frames
• CPC Class Codes: G06T 2207/10068 Endoscopic image
• CPC Class Codes: G06T 2207/10132 Ultrasound image
• CPC Class Codes: G06T 2207/20044 Skeletonization; Medial axis transform
• CPC Class Codes: G06T 2207/30081 Prostate
• CPC Class Codes: G06T 2207/30248 Vehicle exterior or interior
• CPC Class Codes: G06T 7/12 Edge-based segmentation
• CPC Class Codes: G06T 7/60 Analysis of geometric attributes

Abstract

A computerised boundary estimation technique (using prostate as an example) in medical images (ultrasound in particular), called Radial Bas-Relief. An imaging probe can be carried by a robot and shares the same reference frame as the robot. The prostate is scanned and the ultrasound images are fed into a computer which provides computational images processing. Such a method is employed to allow a quick and robust extract of the boundary of interest from transverse images taken transurethrally or transrectally.

Claims

1. A method of producing a computerized boundary estimation in medical images using a Radial Bas-Relief technique, and utilizing a surgical robot having a head axis, a computer equipped with a frame grabber, a 4-axis motion controller, an ultrasound scanner, and one of a transurethral and a transrectal ultrasound probe which passes through an outer/sheath of a resectoscope mounted to said surgical robot, said method comprising the steps of:

(a) engaging said resectoscope to said robot suspended on a counterbalance gantry at an undisturbed reference position (verumontanum); and

(b) scanning for a target organ on a patient by moving said head axis of said surgical robot mounted with said ultrasound probe;

wherein scanned images obtained in (b) are fed into said frame grabber, and images of said target organ are then digitized to enable image processing and boundary estimation outlining by said computer.

2. A computerized boundary estimation in medical images using method as set forth in claim 1, further comprising the steps of:

(c) inverting the medical image of the target organ to obtain an inverted image;

(d) enlarging proportionally said inverted image in an orthogonal direction to obtain an enlarged image;

(e) adding said enlarged image of (d) to said medical image obtained in claim 1 to result in a Bas-relief image containing grey level now with edge information enhanced;

(f) binarising said Bas-relief image obtained in (e) to remove the grey level thereof;

(g) dilating and eroding the binarised image of (f) to obtain a smoother outline of the target organ boundary contour; and

(h) thinning the dilated or eroded image of (g) to provide a skeletonised outline.

3. A computerized boundary estimation method as set forth in claims 1 or 2, wherein the target organ boundary is outlined by the use of a light pen on the monitor screen.

4. A computerized boundary estimation method as set forth in claim 3, wherein the target organ is the prostate.

5. A computerized boundary estimation method as set forth in claims 1 or 2, wherein the target organ boundary is outlined by an automatic capsule delineation program.

6. A computerized boundary estimation method as set forth in claim 5, wherein the target organ is the prostate.

7. A computerized boundary estimation method as set forth in claims 1 or 2, wherein a cutting element is introduced and attached onto the outer sheath of the resectoscope.

8. A computerized boundary estimation method as set forth in claims 1 or 2, wherein the target organ is the prostate.