Method for discriminating between background and tissue of interest, and method and apparatus for generating photo-acoustic images for detecting calcified tissue

• US 9,478,023 B2
• Filed: 12/12/2012
• Issued: 10/25/2016
• 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, Kang, Jeeun, Song, Tai-Kyong, Yoo, Yang Mo
• Primary Examiner(s): Le, Vu
• Assistant Examiner(s): BEG, SAMAH A
• Application Number:
  US14/399,748
• Publication Number:
  US 20150221081A1
• Time in Patent Office: 1,413 Days
• Field of Search: None
• 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.

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 a plurality of wavelengths;

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;

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; and

generating 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 most 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 non-transitory 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 a plurality of wavelengths;

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;

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; and

generating 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 a plurality of wavelengths;

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;

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; and

generating 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;

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, and to generate an image in which a background is discriminated,

wherein each of the pixel intensity detection unit, the index frame generation unit, the signal weight generation unit, and the weight applying unit are implemented by one or more processor.

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;

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, and to generate an image in which a background is discriminated,

wherein each of the pixel intensity detection unit, the maximum/minimum ratio conversion weight generation unit and the weight applying unit are implemented by one or more processor.

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, and to generate an image in which a background is discriminated,

wherein each of the pixel intensity detection unit, the index frame generation unit, the signal weight generation unit, the maximum/minimum ratio conversion weight generation unit, the weight frame generation unit and the weight applying unit are implemented by one or more processor.