Fenghe Zhong

Abstract: High-speed multi-parameter photoacoustic microscopy (PAM) holds immense value in biomedical research, yet its imaging quality is often compromised by noise stemming from limited pulse energy and low average power. This report outlines innovative hardware and algorithmic strategies to enhance imaging quality and throughput in PAM. Firstly, recognizing the constraints imposed by traditional piezoelectric ultrasonic transducers on sensitivity, field-of-view and detection bandwidth due to their size and performance, we adopted a polymer-based micro-ring resonator. This enabled high-speed functional PAM imaging of the living mouse cerebral cortex, facilitating precise tracking and localization of individual red blood cells. Furthermore, we performed a side-by-side comparison with two-photon microscopy to validate the localization accuracy and achieved super-resolution monitoring of ischemic stroke in the cortical region. Secondly, leveraging the oversampling and continuity of axial signals in 3D PAM, we employed a self-supervised single volume denoising algorithm. This approach significantly reduced the required pulse energy for imaging while maintaining the functional imaging ability (sO2 and blood flow). We achieved high quality imaging with 1/10 of the original pulse energy, thereby mitigating potential thermal damage caused by high excitation power and expanding the application potential of high-speed multi-parameter PAM. The development and integration of these innovative methods will serve as a robust toolset for advancing biomedical imaging.

Speaker: Fenghe Zhong works as a postdoctoral research fellow at the Huazhong University of Science and Technology. He received his bachelor’s degree from the Huazhong University of Science and Technology, his MS degree from the University of Rochester, and his PhD from the Washington University in St. Louis. His research focuses on functional photoacoustic microscopy and fluorescence microscopy to advance the understanding of brain metabolism.