Acoustic-resolution photoacoustic microscopy (AR-PAM) is an emerging biomedical imaging modality that combines superior optical sensitivity and fine ultrasonic resolution in an optical quasi-diffusive regime (∼1-3 mm in tissues). AR-PAM has been explored for anatomical, functional, and molecular information in biological tissues. Heretofore, AR-PAM systems have suffered from a limited field-of-view (FOV) and/or slow imaging speed, which have precluded them from routine preclinical and clinical applications. Here, we demonstrate an advanced AR-PAM system that overcomes both limitations of previous AR-PAM systems. The new AR-PAM system demonstrates a super wide-field scanning that utilized a 1-axis water-proofing microelectromechanical systems (MEMS) scanner integrated with two linear stepper motor stages. We achieved an extended FOV of 36 × 80mm2 by mosaicking multiple volumetric images of 36 × 2.5 mm2 with a total acquisition time of 224 seconds. For one volumetric data (i.e., 36 × 2.5 mm2), the B-scan imaging speed over the short axis (i.e., 2.5 mm) was 83 Hz in humans. The 3D volumetric image was also provided by using MEMS mirror scanning along the X-axis and stepper-motor scanning along the Y-axis. The super-wide FOV mosaic image was realized by registering and merging all individual volumetric images. Finally, we obtained multi-plane whole-body in-vivo PA images of small animals, illustrating distinct multi-layered structures including microvascular networks and internal organs. Importantly, we also visualized microvascular networks in human fingers, palm, and forearm successfully. This advanced MEMS-AR-PAM system could potentially enable hitherto not possible wide preclinical and clinical applications.

中文翻译：

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动物和人类体内的超广角光声显微镜。

声分辨率光声显微镜（AR-PAM）是一种新兴的生物医学成像方式，在光学准漫射区（组织中约1-3 mm）结合了卓越的光学灵敏度和精细的超声分辨率。AR-PAM已被研究用于生物组织中的解剖，功能和分子信息。迄今为止，AR-PAM系统受到有限的视野（FOV）和/或成像速度较慢的困扰，这使它们无法进行常规的临床前和临床应用。在这里，我们演示了一种先进的AR-PAM系统，该系统克服了以前的AR-PAM系统的两个局限性。新的AR-PAM系统演示了超广域扫描，该扫描利用了集成了两个线性步进电机级的1轴防水微机电系统（MEMS）扫描仪。通过拼接多个36×2.5 mm2的体积图像，总采集时间为224秒，我们实现了36×80mm2的扩展视野。对于一个体积数据（即36×2.5 mm2），人在短轴（即2.5 mm）上的B扫描成像速度为83 Hz。通过使用沿X轴的MEMS镜面扫描和沿Y轴的步进电机扫描，还可以提供3D体积图像。通过注册和合并所有单个体积图像来实现超宽FOV马赛克图像。最后，我们获得了小动物的多平面全身PA图像，显示了包括微血管网络和内部器官在内的独特的多层结构。重要的是，我们还成功地可视化了人的手指，手掌和前臂中的微血管网络。