Method for reconstructing intravascular photoacoustic two-dimensional image

Abstract

A method for reconstructing an intravascular photoacoustic two-dimensional image is provided. The method comprises: first establishing an initial reconstruction image in a manner that an IVPA imaging device collects a photoacoustic signal; performing once derivation, deconvolution and filtering pre-processing on photoacoustic data that is collected by an imaging guide pipe at each measurement position, and removing influence of an ultrasonic detector pulse response on image reconstruction; and finally calculating a gray-scale value corresponding to each lattice point according to an effective reception angle of the ultrasonic detector and pre-processed photoacoustic data, to obtain a final gray-scale image. According to the method for reconstructing an intravascular photoacoustic two-dimensional image, based on a difference of actual photoacoustic signal collecting devices, device parameters such as an imaging guide pipe radius and a sampling frequency can be flexibly set, a resolution of the reconstruction image is adjusted, a suitable filtering function is selected to pre-process an original photoacoustic signal, and finally an initial photoacoustic pressure intensity distribution image of a target vessel cross section is precisely reconstructed, and the image provides beneficial reference for clinic diagnosis of vascular diseases.

Description

technical field [0001] The invention relates to a method for reconstructing an axial section light absorption distribution image of a blood vessel by using intravascular photoacoustic (intravascular photoacoustic, IVPA) signal inversion, and belongs to the technical field of medical imaging. Background technique [0002] Photoacoustic imaging is a new type of non-destructive medical imaging technology. It is based on the principle that different biological tissues have different optical absorption coefficients for specific wavelength lasers, and then radiates different intensities of ultrasound. An imaging method that reconstructs images from acoustic signals to obtain information about the internal structure of tissues. Applying photoacoustic imaging technology to imaging inside blood vessels can detect the tissue structure of blood vessel walls. The principle of intravascular photoacoustic imaging technology is to uniformly irradiate the pulsed laser or amplitude-modulate...

AI Technical Summary

Problems solved by technology

The principle of intravascular photoacoustic imaging technology is to uniformly irradiate the pulsed laser or amplitude-modulated continuous laser onto the vessel wall, excite the vessel wall to generate photoacoustic signals, and the ultrasonic detector placed on the top of the probe performs a 360° circular rotation to collect images in all directions. The ultrasonic echoes are sent to the computer, and finally the cross-sectional light absorption distribution or the initial photoacoustic pressure distribution image of the blood vessel is reconstructed by an appropriate algorithm, and the tissue structure image and geometric shape information of the blood vessel are obtained, that is, the image reconstruction is based on these original information Based on reconstructing the intravascular photoacoustic image, unlike other photoacoustic tomography systems in which scanning equipment rotates around the imaging object, IVPA images in a closed vascular cavity, and its scanning aperture is closed in the imaging object, so that the data Acquisition methods are highly restricted, making it impossible to directly adopt existing photoacoustic image reconstruction algorithms

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