Image processing apparatus, image processing program, storage medium and ultra-sonograph

• US 8,187,188 B2
• Filed: 03/24/2008
• Issued: 05/29/2012
• Est. Priority Date: 12/20/2007
• Status: Expired due to Fees

• Current Assignee: GIFU University
• Original Assignee: GIFU University
• Inventors: Yokota, Yasunari, Nogata, Fumio, Kawamura, Yoko
• Primary Examiner(s): Cattungal, Sanjay
• Application Number:
  US12/808,487
• Publication Number:
  US 20110112402A1
• Time in Patent Office: 1,527 Days
• Field of Search: 600437-466, 382128-132
• US Class Current: 600/441
• 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 ultrasound B-mode images of consecutive frames to estimate a carotid artery wall at a carotid artery minor axis cross section included in an ultrasound B-mode image of a predetermined frame. The computer 12 also uses, as a template image, the ultrasound B-mode image, which includes the estimated carotid artery wall and surrounding tissues of the carotid artery wall and estimates the size of the diameter of the carotid artery wall so as to minimize a margin of error between a transformed template image, which is created by transforming the template image, and the acquired ultrasound B-mode image of each frame, thereby acquiring the time change of the carotid artery wall.

Claims

1. An image processing apparatus comprising:

a carotid artery wall estimation unit that acquires ultrasound B-mode images of consecutive frames to estimate a carotid artery wall at a carotid artery minor axis cross section included in an ultrasound B-mode image of a predetermined frame; and

a heart rate variability tracking unit that approximates, by the following Equation (1), a template image, which is prepared by representing the ultrasound B-mode image of the predetermined frame in polar coordinates and includes the estimated carotid artery wall and surrounding tissues of the carotid artery wall, to an image, which is prepared by representing each ultrasound B-mode image of the other frames in polar coordinates and determines the amount of displacement of the inner surface of the carotid artery wall according to the following Equation (2) or (3) so as to minimize a square error, which is expressed by the following Equation (4) or (5), thereby acquiring a time change of the carotid artery wall,

2. The image processing apparatus according to claim 1, wherein the carotid artery wall estimation unit determines the value of a carotid artery parameter for determining the position and the shape of the carotid artery so as to maximize an evaluation function indicating the degree of probability of a carotid artery, thereby estimating the carotid artery wall.

3. The image processing apparatus according to claim 1, wherein if there is a deviation in the center of the carotid artery on the ultrasound B-mode image in each frame, the heart rate variability tracking unit also estimates the deviation.

4. 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.

5. A non-transitory computer readable medium having stored thereon a computer executable image processing program which, when executed, causes a computer to implement:

a carotid artery wall estimation unit that acquires ultrasound B-mode images of consecutive frames to estimate a carotid artery wall at a carotid artery minor axis cross section included in an ultrasound B-mode image of a predetermined frame; and

a heart rate variability tracking unit that approximates, by the following Equation (1), a template image, which is prepared by representing the ultrasound B-mode image of the predetermined frame in polar coordinates and includes including the estimated carotid artery wall and surrounding tissues of the carotid artery wall, to an image, which is prepared by representing each ultrasound B-mode image of the other frames in polar coordinates and determines the amount of displacement of the inner surface of the carotid artery wall according to the following Equation (2) or (3) so as to minimize a square error, which is expressed by the following Equation (4) or (5), thereby acquiring a time change of the carotid artery wall,

6. The non-transitory computer readable medium according to claim 5, wherein the carotid artery wall estimation unit determines the value of a carotid artery parameter for determining the position and the shape of the carotid artery so as to maximize an evaluation function indicating the degree of probability of a carotid artery, thereby estimating the carotid artery wall.

7. The non-transitory computer readable medium according to claim 5, wherein if there is a deviation in the center of the carotid artery on the ultrasound B-mode image in each frame, the heart rate variability tracking unit also estimates the deviation.