Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Miaoli County 35053, Taiwan.
Department of Biomedical Engineering, College of Engineering, Chung Yuan Christian University, Taoyuan City 32023, Taiwan.
Biosensors (Basel). 2021 Aug 3;11(8):262. doi: 10.3390/bios11080262.
Photoacoustic (PA) imaging has become one of the major imaging methods because of its ability to record structural information and its high spatial resolution in biological tissues. Current commercialized PA imaging instruments are limited to varying degrees by their bulky size (i.e., the laser or scanning stage) or their use of complex optical components for light delivery. Here, we present a robust acoustic-resolution PA imaging system that consists of four adjustable optical fibers placed 90° apart around a 50 MHz high-frequency ultrasound (US) transducer. In the compact design concept of the PA probe, the relative illumination parameters (i.e., angles and fiber size) can be adjusted to fit different imaging applications in a single setting. Moreover, this design concept involves a user interface built in MATLAB. We first assessed the performance of our imaging system using in vitro phantom experiments. We further demonstrated the in vivo performance of the developed system in imaging (1) rat ear vasculature, (2) real-time cortical hemodynamic changes in the superior sagittal sinus (SSS) during left-forepaw electrical stimulation, and (3) real-time cerebral indocyanine green (ICG) dynamics in rats. Collectively, this alignment-free design concept of a compact PA probe without bulky optical lens systems is intended to satisfy the diverse needs in preclinical PA imaging studies.
光声（PA）成像是一种主要的成像方法，因为它能够记录结构信息并具有较高的生物组织空间分辨率。目前商业化的 PA 成像仪器在其体积（即激光或扫描台）或用于光传输的复杂光学元件方面都受到不同程度的限制。在这里，我们提出了一种稳健的声学分辨率 PA 成像系统，该系统由四个放置在 50MHz 高频超声（US）换能器周围相隔 90°的可调光纤组成。在 PA 探头的紧凑设计概念中，可以调整相对照明参数（即角度和光纤尺寸）以适应单个设置中的不同成像应用。此外，这种设计概念涉及在 MATLAB 中构建用户界面。我们首先使用体外体模实验评估了我们成像系统的性能。我们进一步展示了所开发系统在成像（1）大鼠耳部血管、（2）左前爪电刺激期间上矢状窦（SSS）皮质血流动力学的实时变化、（3）大鼠吲哚菁绿（ICG）的实时脑动力学中的体内性能。总的来说，这种无笨重光学透镜系统的紧凑型 PA 探头的无对准设计概念旨在满足临床前 PA 成像研究的多样化需求。
