Opt Lett. 2020 May 15;45(10):2756-2759. doi: 10.1364/OL.391824.
Capable of imaging blood perfusion, oxygenation, and flow simultaneously at the microscopic level, multi-parametric photoacoustic microscopy (PAM) has quickly emerged as a powerful tool for studying hemodynamic and metabolic changes due to physiological stimulations or pathological processes. However, the low scanning speed poised by the correlation-based blood flow measurement impedes its application in studying rapid microvascular responses. To address this challenge, we have developed a new, to the best of our knowledge, multi-parametric PAM system. By extending the optical scanning range with a cylindrically focused ultrasonic transducer (focal zone, 76µ×4.5) for simultaneous acquisition of 500 B-scans, the new system is 112 times faster than our previous multi-parametric system that uses a spherically focused transducer (focal diameter, 40 µm) and enables high-resolution imaging of blood perfusion, oxygenation, and flow over an area of 4.5×1 at a frame rate of 1 Hz. We have demonstrated the feasibility of this system in the living mouse ear. Further development of this system into reflection mode will enable real-time cortex-wide imaging of hemodynamics and metabolism in the mouse brain.
能够在微观水平上同时成像血液灌注、氧合和血流，多参数光声显微镜（PAM）迅速成为研究生理刺激或病理过程中血液动力学和代谢变化的有力工具。然而，基于相关的血流测量的低扫描速度阻碍了其在研究快速微血管反应中的应用。为了解决这一挑战，我们开发了一种新的、据我们所知的多参数 PAM 系统。通过使用圆柱形聚焦超声换能器（焦点，76µ×4.5）扩展光学扫描范围，同时采集 500 个 B 扫描，新系统比我们之前使用球形聚焦换能器（焦点直径，40 µm）的多参数系统快 112 倍，能够以 1 Hz 的帧率在 4.5×1 的区域上实现高分辨率的血液灌注、氧合和血流成像。我们已经在活体小鼠耳朵中证明了该系统的可行性。进一步将该系统开发为反射模式，将能够实时对小鼠大脑中的血液动力学和代谢进行皮层范围成像。
