IMAGE PROCESSING APPARATUS, IMAGE PROCESSING PROGRAM, STORAGE MEDIUM, AND ULTRA-SONIC DIAGNOSTIC APPARATUS

• US 20110105901A1
• Filed: 03/24/2008
• Published: 05/05/2011
• Est. Priority Date: 12/20/2007
• Status: Active Grant

• Current Assignee: GIFU University
• Original Assignee: GIFU University
• Inventors: Taniguchi, Rie, Kawamura, Yoko, Yokota, Yasunari, Nogata, Fumio
• Granted Patent: US 8,249,324 B2
• Time in Patent Office: Days
• US Class Current: 600/443
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 8/0858 involving measuring tissue layers, e.g. skin, interfaces
• CPC Class Codes: A61B 8/463 characterised by displaying multiple images or images and diagnostic data on one display composite display in devices for short-range imaging with acoustic waves G01S7/52074
• CPC Class Codes: A61B 8/485 involving measuring strain or elastic properties
• CPC Class Codes: G01S 7/52042 determining elastic properties of the propagation medium or of the reflective target diagnostic techniques involving the measurement of strain A61B8/485

Abstract

A computer 12 of an image processing apparatus 11 acquires a moving image including a minor axis cross section of a carotid artery and a cross section of surrounding tissues around the carotid artery and estimates, from images of two temporally different frames of the acquired moving image, an optical flow of each point included in an area corresponding to a carotid artery wall and an optical flow of each point included in an area corresponding to the surrounding tissues. Based on the estimated optical flow of each point, the computer 12 calculates an amount of displacement of the carotid artery and the surrounding tissues with respect to a radial direction of the carotid artery depending on a change in internal pressure of the carotid artery. The computer 12 also calculates an amount of displacement of the carotid artery and the surrounding tissues with respect to the radial direction of the carotid artery depending on a change in the internal pressure of the carotid artery based on a theoretical expression obtained by modeling the carotid artery and the surrounding tissues with a two-layer cylinder. The computer 12 calculates the elastic modulus of the carotid artery wall and the elastic modulus of the surrounding tissues so as to minimize a square error between the two calculated amounts of displacement.

Claims

1. An image processing apparatus comprising:

a first calculation unit for acquiring a moving image including a minor axis cross section of a carotid artery and a cross section of surrounding tissues around the carotid artery, estimating, from images of two temporally different frames of the acquired moving image, an optical flow of each point included in an area corresponding to a carotid artery wall and an optical flow of each point included in an area corresponding to the surrounding tissues, and calculating, based on the estimated optical flow of each point, an amount of displacement of the carotid artery and the surrounding tissues with respect to a radial direction of the carotid artery depending on a change in internal pressure of the carotid artery; and

a second calculation unit for calculating an amount of displacement of the carotid artery and the surrounding tissues with respect to the radial direction of the carotid artery depending on a change in the internal pressure of the carotid artery based on a theoretical expression obtained by modeling the carotid artery and the surrounding tissues with a two-layer cylinder and calculating the elastic modulus of the carotid artery wall and the elastic modulus of the surrounding tissues so as to minimize a square error between the thus calculated amount of displacement and the amount of displacement calculated by the first calculation unit.

2. The image processing apparatus according to claim 1, wherein the first calculation unit estimates the optical flow of each point on an axis extending in the radial direction of the carotid artery from the images of the two frames and calculates, based on the estimated optical flow of each point, the amount of displacement of the carotid artery and the surrounding tissues with respect to the radial direction of the carotid artery depending on a change in the internal pressure of the carotid artery.

6. Ultrasonic diagnostic equipment being connected to the image processing apparatus according to claim 1, generating an ultrasound B-mode image based on an echo signal obtained through transmission and reception of ultrasound by a probe, and outputting the generated ultrasound B-mode image to the image processing apparatus.

3. An image processing program causing a computer to function as:

a first calculation unit for acquiring a moving image including a minor axis cross section of a carotid artery and a cross section of surrounding tissues around the carotid artery, estimating, from images of two temporally different frames of the acquired moving image, an optical flow of each point included in an area corresponding to a carotid artery wall and an optical flow of each point included in an area corresponding to the surrounding tissues, and calculating, based on the estimated optical flow of each point, an amount of displacement of the carotid artery and the surrounding tissues with respect to a radial direction of the carotid artery depending on a change in internal pressure of the carotid artery; and

a second calculation unit for calculating an amount of displacement of the carotid artery and the surrounding tissues with respect to the radial direction of the carotid artery depending on a change in the internal pressure of the carotid artery based on a theoretical expression obtained by modeling the carotid artery and the surrounding tissues with a two-layer cylinder and calculating the elastic modulus of the carotid artery wall and the elastic modulus of the surrounding tissues so as to minimize a square error between the thus calculated amount of displacement and the amount of displacement calculated by the first calculation unit.

4. The image processing program according to claim 3, wherein the first calculation unit estimates the optical flow of each point on an axis extending in the radial direction of the carotid artery from the images of the two frames and calculates, based on the estimated optical flow of each point, the amount of displacement of the carotid artery and the surrounding tissues with respect to the radial direction of the carotid artery depending on a change in the internal pressure of the carotid artery.

5. A storage medium storing the image processing program according to claim 3.