Optical imaging apparatus for diagnosis and image processing method

Patent metadata

Field	Value
Publication number	US-11179059-B2
Application number	US-201715431969-A
Country	US
Kind code	B2
Filing date	Feb 14, 2017
Priority date	Mar 25, 2011
Publication date	Nov 23, 2021
Grant date	Nov 23, 2021

Abstract

An optical imaging apparatus for diagnosis generates a closed curve which precisely reproduces the shape of the indwelled stent and the shape of the inner wall of the biological tissue at the indwelling position of the stent. The optical imaging apparatus analyzes intensity change in transmission direction of the light from the transmission and reception unit for every one of the respective line data; based on the result of the analysis detects pixel data expressing the stent position in the transmission direction; labels each pixel data expressing the detected stent position; eliminates, within the respective labeling groups applied with the same labels, labeling groups in each of which the number of pixel data in the circumferential direction is a predetermined value or less; calculates center position for each labeling group not eliminated; and generates a stent closed-curve using the center position of each labeling group.

First claim

What is claimed is:

1. An optical imaging apparatus for diagnosis which obtains reflection light from biological tissue of a body lumen by moving a transmission and reception unit, that carries out optical transmission and reception, continuously in an axial direction while rotating the unit in a circumferential direction inside the body lumen, and which constructs a tomographic image of the biological tissue using line data of interference light obtained by making the obtained reflection light and a reference light interfere with each other, the optical imaging apparatus comprising:
first analysis means for reading-out line data used for constructing a predetermined tomographic image and for analyzing intensity change in transmission direction of the light from the transmission and reception unit for every line data;
first detection means for detecting, based on the analysis result by the first analysis means, pixel data expressing a stent position for every line data;
input means for inputting information identifying a thickness of the stent; and
reconstruction means for reconstructing, when the stent thickness is inputted to the input means, the tomographic image by changing the pixel data for each of a plurality of the line data to include an additional number of pixels in the transmission direction so that the number of pixels in the pixel data for each of the plurality of the line data corresponds to the thickness of the stent in a display showing the stent,
wherein the first analysis means analyzes the intensity change by finding average inclination of the line data within a predetermined range in the transmission direction for every predetermined distance, and the first detection means detects pixel data in which the intensity change becomes maximum.

2. The optical imaging apparatus for diagnosis according to claim 1 , wherein the reconstruction means further comprises:
labeling means for labeling each pixel data expressing the stent position detected for every line data based on positional information of each pixel data;
elimination means for eliminating, within respective labeling groups applied with the same labels in the labeling means, labeling groups in which the number of pixel data in circumferential direction, which is included in one labeling group, is a predetermined value or less;
calculation means for calculating a center position of each labeling group, which was not eliminated in the elimination means, based on the positional information of each pixel data, and wherein
the tomographic image is reconstructed, after changing the pixel data for the number of pixels corresponding to the thickness of the stent, into a display showing the stent toward the transmission direction from the center position calculated by the calculation means.

3. The optical imaging apparatus for diagnosis according to claim 1 , further comprising:
second analysis means for reading-out line data used for a construction of a predetermined tomographic image and for analyzing maximum intensity in the transmission direction of light from the transmission and reception unit for every line data;
second detection means for detecting pixel data expressing inner-wall position for every line data based on the analysis result by the second analysis means;
labeling means for labeling each pixel data expressing the inner-wall position detected for every line data based on positional information of each pixel data;
elimination means for eliminating a labeling group in which the variation of positional information of pixel data, included in one labeling group within the respective labeling groups applied with the same labels by the labeling means, in the transmission direction is larger than a predetermined variation;
calculation means for calculating, with regard to each labeling group which was not eliminated by the elimination means, center position of the labeling group based on positional information of each pixel data of the labeling group; and
generation means for generating an inner-wall closed-curve by using the center position of each labeling group, which was calculated by the calculation means.

4. An image processing method of an optical imaging apparatus for diagnosis which obtains reflection light from biological tissue of a body lumen by moving a transmission and reception unit, that carries out optical transmission and reception, continuously in an axial direction while rotating the unit in a circumferential direction inside the body lumen, and which constructs a tomographic image of the biological tissue using line data of interference light obtained by making the obtained reflection light and a reference light interfere with each other, the method comprising:
reading-out line data used for construction of a predetermined tomographic image and for analyzing intensity change in transmission direction of the light from the transmission and reception unit for every line data;
detecting, based on a result of the analyzing of the intensity change, pixel data expressing stent position for every line data;
inputting information relating to thickness of the stent; and
reconstructing the tomographic image, when an instruction is inputted that the thickness of the stent is to be displayed, by changing the pixel data for each of a plurality of the line data to include an additional number of pixels in the transmission direction so that the number of pixels in the pixel data for each of the plurality of the line data corresponds to the thickness of the stent in a display showing the stent,
wherein the intensity change is analyzed by finding average inclination of the line data within a predetermined range in the transmission direction for every predetermined distance, and the pixel data in which the intensity change becomes maximum is detected.

5. The image processing method of an optical imaging apparatus for diagnosis according to claim 4 , wherein the reconstruction process further comprises:
labeling process for labeling each pixel data expressing the stent position detected for every line data based on positional information of each pixel data;
elimination process for eliminating, within the respective labeling groups applied with the same labels in the labeling process, labeling groups in which the number of pixel data in circumferential direction, which is included in one labeling group, is a predetermined value or less;
calculation process for calculating a center position of each labeling group, which was not eliminated in the elimination process, based on positional information of each pixel data; and

wherein the tomographic image is reconstructed after changing the pixel data for the number of pixels corresponding to the thickness into a display showing the stent toward the transmission direction from the center position calculated in the calculation process.

Assignees

• Terumo Corp

Inventors

• Furuichi Junya
• Kaneko Kenji

Classifications

• A61B5/061 Primary

  Determining position of a probe within the body employing means separate from the probe, e.g. sensing internal probe position employing impedance electrodes on the surface of the body (A61B1/00158 takes precedence) · CPC title

• A61B1/000094 Primary

  extracting biological structures · CPC title

• A61B5/0066

  Optical coherence imaging · CPC title

• A61B5/1077

  Measuring of profiles · CPC title

• G16H30/40

  for processing medical images, e.g. editing · CPC title