Method and apparatus for motion estimation within biological tissue

• US 6,277,074 B1
• Filed: 10/01/1999
• Issued: 08/21/2001
• Est. Priority Date: 10/02/1998
• Status: Expired due to Fees

• Current Assignee: University of Kansas Medical Center
• Original Assignee: University of Kansas Medical Center
• Inventors: Zhu, Yanning, Chaturvedi, Pawan, Insana, Michael F., Hall, Timothy J.
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): Imam, Ali M.
• Application Number:
  US09/410,574
• Time in Patent Office: 690 Days
• Field of Search: 600/437-449, 600/454-456, 73/619-626
• US Class Current: 600/437
• CPC Class Codes: A61B 5/0053 by applying pressure, e.g. compression, indentation, palpation, grasping, gauging
• CPC Class Codes: A61B 8/0833 involving detecting or locating foreign bodies or organic structures
• CPC Class Codes: A61B 8/485 involving measuring strain or elastic properties

Abstract

A method for motion estimation within biological tissue is disclosed. The method involves acoustically coupling a transducer to a target biological tissue, which transducer emits an ultrasonic signal and collects the energy back-scattered by the target issue. A first set of energy data is collected and stored, then target tissue is axially compressed and a second set of ultrasonic energy data is collected and stored. One of the first and second data sets is warped to account for the anticipated compression forming a warped data set. This warped data set is cross-correlated with the unwarped one of the first and said second data sets to obtain a fine scale displacement of said target biological tissue from the displacement estimated by the warping. This fine scale displacement is summed with the warped data set to obtain a total axial displacement. A gradient of the total axial displacement is taken and used to form a strain image. An apparatus for practicing this method is also disclosed.

Claims

1. A method for motion estimation within biological tissue comprising:

(a) acoustically coupling a transducer to a target biological tissue;

(b) emitting at least one ultrasonic signal from said transducer into said target tissue along a scan plane;

(c) collecting ultrasonic energy back-scattered by at least said target biological tissue;

(d) storing said back-scattered ultrasonic energy collected in step (c) as a first data set;

(e) compressing said target biological tissue in a substantially axial direction;

(f) emitting at least one ultrasonic signal from said transducer into said target tissue along said scan plane while substantially maintaining said compression;

(g) collecting ultrasonic energy back-scattered by at least said target biological tissue under said compression;

(h) storing said back-scattered ultrasonic energy collected in step (g) as a second data set;

(i) warping one of said first and second data sets to account for said compression to form a warped data set;

(j) cross-correlating said warped data set with the unwarped one of said first and said second data sets to obtain a fine scale displacement of said target biological-tissue from the displacement estimated by said warping.

(k) summing said fine scale displacement and said warped data set to obtain a total axial displacement;

(l) taking a gradient of said total axial displacement; and

(m) forming a strain image from said gradient of said total axial displacement.