High-speed wide-field photoacoustic microscopy using a cylindrically focused transparent high-frequency ultrasound transducer

作者：Maomao Chen, Laiming Jiang, Clare Cook, Yushun Zeng, Tri Vu, Ruimin Chen, Gengxi Lu, Wei Yang, Ulrike Hoffmann, Qifa Zhou, Junjie Yao · 发表于：Photoacoustics · 年份：2022 · DOI：10.1016/j.pacs.2022.100417 · 被引用次数：40 · 研究领域：Photoacoustic and Ultrasonic Imaging、Thermography and Photoacoustic Techniques、Nanoplatforms for cancer theranostics

Combining focused optical excitation and high-frequency ultrasound detection, optical-resolution photoacoustic microscopy (OR-PAM) can provide micrometer-level spatial resolution with millimeter-level penetration depth and has been employed in a variety of biomedical applications. However, it remains a challenge for OR-PAM to achieve a high imaging speed and a large field of view at the same time. In this work, we report a new approach to implement high-speed wide-field OR-PAM, using a cylindrically-focused transparent ultrasound transducer (CFT-UT). The CFT-UT is made of transparent lithium niobate coated with indium-tin-oxide as electrodes. A transparent cylindrical lens is attached to the transducer surface to provide an acoustic focal line with a length of 9 mm. The excitation light can pass directly through the CFT-UT from the above and thus enables a reflection imaging mode. High-speed imaging is achieved by fast optical scanning of the focused excitation light along the CFT-UT focal line. With the confocal alignment of the optical excitation and acoustic detection, a relatively high detection sensitivity is maintained over the entire scanning range. The CFT-UT-based OR-PAM system has achieved a cross-sectional frame rate of 500 Hz over the scanning range of 9 mm. We have characterized the system's performance on phantoms and demonstrated its application on small animal models in vivo. We expect the new CFT-UT-based OR-PAM will find matched biomedical applications that ...