METHOD FOR DISCRIMINATING BETWEEN BACKGROUND AND TISSUE OF INTEREST, AND METHOD AND APPARATUS FOR GENERATING PHOTOACOUSTIC IMAGES FOR DETECTING CALCIFIED TISSUE

• US 20150221081A1
• Filed: 12/12/2012
• Published: 08/06/2015
• Est. Priority Date: 05/09/2012
• Status: Active Grant

• Current Assignee: Sogang University Research Foundation
• Original Assignee: Sogang University Industry-University Cooperation Foundation
• Inventors: Chang, Jin Ho, Song, Tai-Kyong, Yoo, Yang Mo, Kang, Jeeun
• Granted Patent: US 9,478,023 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• CPC Class Codes: G06F 18/22 Matching criteria, e.g. proximity measures
• CPC Class Codes: G06T 2207/30004 Biomedical image processing
• CPC Class Codes: G06T 7/0012 Biomedical image inspection
• CPC Class Codes: G06T 7/11 Region-based segmentation
• CPC Class Codes: G06T 7/194 involving foreground-background segmentation
• CPC Class Codes: G06V 10/143 Sensing or illuminating at different wavelengths
• CPC Class Codes: G06V 20/698 Matching; Classification

Abstract

Provided is a method for discriminating a tissue of interest and a method for generating photo-acoustic images to detect a calcified tissue, which includes: detecting an intensity of each pixel of a tissue-of-interest image obtained for each wavelength; matching an index corresponding to an image, which has a greatest intensity corresponding to each pixel, to each pixel; generating a signal weight corresponding to each pixel in consideration of a wavelength absorbed by the tissue of interest; and applying the generated signal weight of each pixel to each pixel of an image obtained with a wavelength, which is the most absorbed by the tissue of interest, to generate an image in which a background is discriminated. A photo-acoustic image obtained while changing an optical wavelength may be analyzed to endow an index to each pixel of the image, and a background signal and a signal to be obtained may be discriminated by using the endowed index.

Claims

1. A method for discriminating a tissue of interest, comprising:

detecting an intensity of each pixel of a tissue-of-interest image obtained for each wavelength;

matching an index corresponding to an image, which has a greatest intensity corresponding to each pixel, to each pixel;

generating a signal weight corresponding to each pixel in consideration of a wavelength absorbed by the tissue of interest; and

applying the generated signal weight of each pixel to each pixel of an image obtained with a wavelength, which is the most absorbed by the tissue of interest, to generate an image in which the tissue of interest is discriminated.

2. The method for discriminating a tissue of interest according to claim 1,

wherein, in said generating of a signal weight, a signal weight of a pixel corresponding to an index of a wavelength, at which an optical absorption coefficient of the tissue of interest and an optical absorption coefficient of a surrounding tissue are the most different from each other, is selected as a greatest value.

3. The method for discriminating a tissue of interest according to claim 1,

wherein a signal weight of a pixel corresponding to an index of a wavelength, at which a difference between an optical absorption coefficient of the tissue of interest and an optical absorption coefficient of a surrounding tissue is maximum, is selected as a greatest value even though the index is not an index of a wavelength at which optical energy is the most absorbed by the tissue of interest.

4. The method for discriminating a tissue of interest according to claim 1,

wherein a signal weight of a pixel corresponding to an index of a wavelength, which is the most absorbed by the tissue of interest, is selected as a greatest value.

5. The method for discriminating a tissue of interest according to claim 1,

wherein a signal weight of a pixel corresponding to an index of a wavelength, which is the second absorbed by the tissue of interest, is set to be equal to or greater than 0 and smaller than a signal weight of the pixel corresponding to the index of a wavelength, which is the most absorbed by the tissue of interest.

9. A computer-readable recording medium, in which a program for executing the method defined in claim 1 in a computer is recorded.

6. A method for discriminating a tissue of interest, comprising:

detecting an intensity of each pixel of a tissue-of-interest image obtained for each wavelength;

generating a maximum/minimum ratio conversion weight, which is to be applied to each pixel, by using a ratio between a maximum value and a minimum value of the intensity corresponding to each pixel; and

applying the generated maximum/minimum ratio conversion weight to each pixel of an image obtained with a wavelength, which is the most absorbed by the tissue of interest, to generate an image in which a background is discriminated.

7. The method for discriminating a tissue of interest according to claim 6,

wherein, when a difference between the maximum value and the minimum value is greater than a predetermined value, the pixel is determined as a pixel of the tissue of interest and a maximum value of the maximum/minimum ratio conversion weight is endowed, and when the difference between the maximum value and the minimum value is smaller than the predetermined value, the pixel is determined as a background and a minimum value of the maximum/minimum ratio conversion weight is endowed.

8. A method for discriminating a tissue of interest, comprising:

detecting an intensity of each pixel of a tissue-of-interest image obtained for each wavelength;

matching an index corresponding to an image, which has a greatest intensity corresponding to each pixel, to each pixel;

generating a signal weight corresponding to each pixel in consideration of a wavelength absorbed by the tissue of interest;

generating a maximum/minimum ratio conversion weight, which is to be applied to each pixel, by using a ratio between a maximum value and a minimum value of the intensity corresponding to each pixel;

generating a final weight by using the signal weight and the maximum/minimum ratio conversion weight; and

applying the generated final weight of each pixel to each pixel of an image obtained with a wavelength, which is the most absorbed by the tissue of interest, to generate an image in which a background is discriminated.

10. An apparatus for discriminating a tissue of interest, comprising:

a pixel intensity detection unit configured to detect an intensity of each pixel of a tissue-of-interest image obtained for each wavelength;

an index frame generation unit configured to match an index corresponding to an image, which has a greatest intensity corresponding to each pixel, to each pixel to generate an index frame;

a signal weight generation unit configured to generate a signal weight corresponding to each pixel in consideration of a wavelength absorbed by the tissue of interest; and

a weight applying unit configured to apply the generated signal weight of each pixel to each pixel of an image obtained with a wavelength, which is the most absorbed by the tissue of interest, to generate an image in which a background is discriminated.

11. An apparatus for discriminating a tissue of interest, comprising:

a pixel intensity detection unit configured to detect an intensity of each pixel of a tissue-of-interest image obtained for each wavelength;

a maximum/minimum ratio conversion weight generation unit configured to generate a maximum/minimum ratio conversion weight, which is to be applied to each pixel, by using a ratio between a maximum value and a minimum value of the intensity corresponding to each pixel; and

a weight applying unit configured to apply the generated maximum/minimum ratio conversion weight to each pixel of an image obtained with a wavelength, which is the most absorbed by the tissue of interest, to generate an image in which a background is discriminated.

12. An apparatus for discriminating a tissue of interest, comprising:

a pixel intensity detection unit configured to detect an intensity of each pixel of a tissue-of-interest image obtained for each wavelength;

an index frame generation unit configured to match an index corresponding to an image, which has a greatest intensity corresponding to each pixel, to each pixel to generate an index frame;

a signal weight generation unit configured to generate a signal weight corresponding to each pixel in consideration of a wavelength absorbed by the tissue of interest;

a maximum/minimum ratio conversion weight generation unit configured to generate a maximum/minimum ratio conversion weight, which is to be applied to each pixel, by using a ratio between a maximum value and a minimum value of the intensity corresponding to each pixel;

a weight frame generation unit configured to generate a final weight by using the signal weight and the maximum/minimum ratio conversion weight to generate a weight frame; and

a weight applying unit configured to apply the generated final weight of each pixel to each pixel of an image obtained with a wavelength, which is the most absorbed by the tissue of interest, to generate an image in which a background is discriminated.