Abstract：A simple and fast image reconstruction method based on filtered back-projection (FBP) that has been widely applied in photoacoustic tomography (PAT) was proposed for intravascular photoacoustic (IVPA) imaging. First, the raw photoacoustic signals generated by the tissues were preprocessed by filtering, deconvolution and first-order derivation in time domain. Then, according to the specificity of IVPA scanning in the closed vascular lumen, the pre-processed photoacoustic signal data were back-projected along arcs with a weighting method to obtain the initial photoacoustic pressure of each grid point in the imaging region outside the catheter. Finally, grayscale images displaying the morphological structure of vascular cross-sections were constructed. The experimental results with a computer-simulated vessel phantom show that the structural similarity (SSIM) of the reconstructed image reached 0.5717. The image quality was improved by setting a proper filter prototype, cut-off frequency and the number of measuring positions. The structural information of the vessel wall and plaque tissues can be effectively enhanced through first-order derivation performed to the raw photoacoustic signals. This method provides the foundation for subsequent optimization of image reconstruction algorithm.
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