Search

CN-117017225-B - Angiography method based on optical coherence tomography

CN117017225BCN 117017225 BCN117017225 BCN 117017225BCN-117017225-B

Abstract

The invention provides an angiography method based on optical coherence tomography, which comprises the steps of firstly, carrying out B scanning and C scanning on biological tissues through an optical coherence tomography system to obtain a three-dimensional structure image. Preprocessing the interference spectrum of each A scanning signal of the B scanning, and decomposing the interference spectrum into N sub-interference spectrum signals, wherein N is more than or equal to 2. And carrying out Fourier transform on the sub-interference spectrum signals to obtain N groups of structural diagram data at the same position. The speckle variance is resolved for the N sets of block diagram data and averaged in the depth direction. Compared with the prior art, the angiography method does not need to repeatedly acquire signals at the same position, greatly improves the acquisition speed of the system, and can avoid the interference of the shake of a living sample in the traditional optical coherence tomography angiography system on the reconstructed image.

Inventors

  • BIAN HAIYI

Assignees

  • 淮阴工学院

Dates

Publication Date
20260505
Application Date
20230831

Claims (5)

  1. 1. An angiography method based on optical coherence tomography, comprising the steps of: The method comprises the steps of 1, carrying out B scanning and C scanning on a sample based on an optical coherence tomography system to complete acquisition of three-dimensional interference spectrum signals, wherein when the sample is scanned based on the optical coherence tomography system, the scanning mode of a vibrating mirror is that interference spectrum is acquired only once at the same position; Step 2, preprocessing an interference spectrum of each A scanning signal of the B scanning, and decomposing the interference spectrum into N sub-interference spectrum signals, wherein N is more than or equal to 2; step 3, carrying out Fourier transform on the sub-interference spectrum signals to obtain N groups of structural diagram data at the same position; and 4, solving speckle variance for the N groups of structural image data, and averaging the speckle variance in the depth direction.
  2. 2. The angiography method according to claim 1, wherein in the step 2, the interference spectrum is decomposed into 2 sub-interference spectrum signals, and fourier transformation is performed on the two sub-interference spectrum signals to obtain 2-group structural diagram data of the same position.
  3. 3. The angiography method based on optical coherence tomography of claim 1, wherein in the step 2, the interference spectrum is decomposed into N sub-interference spectrum signals, the N sub-interference spectrum signals are fourier transformed to obtain N groups of structural diagram data at the same position, and the overlapping proportion of the sub-interference spectrum signals in the wavelength domain is less than 80%.
  4. 4. The angiography method according to claim 1, wherein the optical coherence tomography system comprises a light source SLD, a fiber coupler FC1, a mirror M1, polarization controllers PC1 to PC4, lenses L1 to L4 and a focusing lens FL, a scanning galvanometer GM, a Grating and a CCD when scanning is performed based on the optical coherence tomography system in step 1; The reference arm is provided with a reflecting mirror M1 and a lens L1, and the sample arm is provided with lenses L2 and L3 and a scanning galvanometer GM; the polarization controllers PC 1-PC 4 are used for controlling the polarization states of four optical paths input and output by the optical fiber coupler FC 1; The optical fiber coupler FC1 couples the broadband light source emitted by the light source SLD and then respectively enters the reference arm and the sample arm, the reflected light of the reference arm and the sample arm returns to the optical fiber coupler FC1, the reflected light is output by the output end and collimated and then enters the diffraction Grating graining, and the reflected light is focused on the CCD through the focusing lens to acquire an interference spectrum.
  5. 5. The angiography method according to any one of claims 1-4, wherein the preprocessing of the interference spectrum in step 2 comprises resampling, interpolation and denoising.

Description

Angiography method based on optical coherence tomography Technical Field The invention relates to an optical coherence tomography system, in particular to an angiography method based on optical coherence tomography. Background The nutrients and oxygen needed by human body are transported to each tissue and organ of human body through blood circulation, and the blood circulation plays the roles of metabolism and immunity in the tissue, so that the blood circulation can reflect the health condition of human body. Optical coherence tomography has the advantages of high sensitivity, high speed, high resolution, non-invasiveness, non-contact, etc., and has been applied to vascular imaging. For example, doppler Optical Coherence Tomography (OCT) techniques utilize Doppler shift of dynamic signals to extract blood flow signals from static tissue, and heterodyne detection techniques to separate the static and dynamic signals by introducing a fixed modulation frequency into the reference arm, thereby reconstructing the blood vessel. However, current vessel reconstruction relies on the transformation of the optical signal in time, space or frequency caused by the fluidity of the blood, which requires the reconstruction of the vessel from different signals acquired at the same location, reconstructing the vessel by extracting the differences in the signals. Disadvantages of these methods include 1) a significant reduction in the imaging speed of the system, and 2) a significant impact of jitter in the living sample on the reconstruction of the blood vessel. Many efforts have been made by many groups to solve these problems by J.A. WINKELMANN et al to reconstruct blood vessels using a spectral contrast-based method that uses the spectral differences of hemoglobin from other tissues at 620nm and 557nm to achieve single spectrum reconstruction of blood vessels, however this method requires no universality with respect to the wavelength of the light source. Disclosure of Invention Aiming at the problems pointed out in the background art, the invention discloses an angiography method based on optical coherence tomography, which does not need to repeatedly acquire signals at the same position, greatly improves the acquisition speed of the system, and can avoid the interference of the shake of a living sample on a reconstructed image in the traditional optical coherence tomography angiography system. The invention discloses an angiography method based on optical coherence tomography, which comprises the following steps: Step 1, B scanning and C scanning are carried out on a sample based on an optical coherence tomography system, and acquisition of three-dimensional interference spectrum signals is completed; Step 2, preprocessing an interference spectrum of each A scanning signal of the B scanning, and decomposing the interference spectrum into N sub-interference spectrum signals, wherein N is more than or equal to 2; step 3, carrying out Fourier transform on the sub-interference spectrum signals to obtain N groups of structural diagram data at the same position; and 4, solving speckle variance for the N groups of structural image data, and averaging the speckle variance in the depth direction. Further, when the sample is scanned based on the optical coherence tomography system, the scanning mode of the galvanometer is that only one interference spectrum is acquired at the same position. Further, in the step2, the interference spectrum is decomposed into 2 sub-interference spectrum signals, and fourier transformation is performed on the two sub-interference spectrum signals, so that 2 groups of structural diagram data at the same position are obtained. Further, in the step 2, the interference spectrum is decomposed into N sub-interference spectrum signals, fourier transformation is performed on the N sub-interference spectrum signals, so as to obtain N groups of structural diagram data at the same position, and the overlapping proportion of the sub-interference spectrum signals in the wavelength domain is less than 80%. Further, in the step 1, when scanning is performed based on the optical coherence tomography system, the optical coherence tomography system comprises a light source SLD, an optical fiber coupler FC1, a reflecting mirror M1, polarization controllers PC 1-PC 4, lenses L1-L4, a focusing lens FL, a scanning galvanometer GM, a Grating graining and a CCD; The reference arm is provided with a reflecting mirror M1 and a lens L1, and the sample arm is provided with lenses L2 and L3 and a scanning vibrating mirror GM; the polarization controllers PC 1-PC 4 are used for controlling the polarization states of four optical paths input and output by the optical fiber coupler FC 1; The optical fiber coupler FC1 couples the broadband light source emitted by the light source SLD and then respectively enters the reference arm and the sample arm, the reflected light of the reference arm and the sample arm returns to the optica