Three-dimensional super-resolution photoacoustic microscopy method and system based on point spread function

Optical-resolution photoacoustic microscopy is a promising imaging technique that integrates the high spatial resolution of optical imaging with the deep tissue penetration of ultrasound, enabling structural and functional imaging of biological tissues at the micrometer scale. However, the divergence of the excited Gaussian beam leads to a substantial degradation in practical resolution compared to the theoretical resolution, limiting the accuracy of three-dimensional imaging of living tissues. Therefore, there is an urgent need for an effective method to enhance the resolution without altering the hardware configuration. This article presents a three-dimensional super-resolution photoacoustic microscopy method and system based on point spread function. The method utilizes a depth-variant point spread function to model the spatially varying resolution across imaging depths. This function is incorporated into a deconvolution framework, effectively reducing background noise and enhancing the accuracy of resolution enhancement. Experimental results on tungsten wire phantoms and zebrafish suggest that the practical resolution of system can be improved to 2.59μm, which is 1.5 times greater than conventional system. The method successfully addresses the challenges of image blurring and structural information loss due to the inherent characteristics of the Gaussian beam, achieving high lateral resolution. All the results suggest that the system with higher lateral resolution has significant potential for a wide range of practical biomedical applications.