Moothanchery Mohesh, Sharma Arunima, Pramanik Manojit
School of Chemical and Biomedical Engineering, Nanyang Technological University.
School of Chemical and Biomedical Engineering, Nanyang Technological University;
J Vis Exp. 2017 Jun 26(124):55810. doi: 10.3791/55810.
Photoacoustic microscopy (PAM) is a fast-growing invivo imaging modality that combines both optics and ultrasound, providing penetration beyond the optical mean free path (~1 mm in skin) with high resolution. By combining optical absorption contrast with the high spatial resolution of ultrasound in a single modality, this technique can penetrate deep tissues. Photoacoustic microscopy systems can have either a low acoustic resolution and probe deeply or a high optical resolution and probe shallowly. It is challenging to achieve high spatial resolution and large depth penetration with a single system. This work presents an AR-OR-PAM system capable of both high-resolution imaging at shallow depths and low-resolution deep-tissue imaging of the same sample in vivo. A lateral resolution of 4 µm with 1.4 mm imaging depth using optical focusing and a lateral resolution of 45 µm with 7.8 mm imaging depth using acoustic focusing were successfully demonstrated using the combined system. Here, in vivo small-animal blood vasculature imaging is performed to demonstrate its biological imaging capability.
光声显微镜（PAM）是一种快速发展的体内成像模式，它结合了光学和超声技术，能够在超过光学平均自由程（皮肤中约为1毫米）的深度进行高分辨率成像。通过在单一模式中结合光学吸收对比度和超声的高空间分辨率，该技术可以穿透深层组织。光声显微镜系统可以具有低声分辨率并进行深度探测，或者具有高光学分辨率并进行浅层探测。使用单一系统实现高空间分辨率和大深度穿透具有挑战性。这项工作展示了一种AR-OR-PAM系统，该系统能够在体内对同一样本进行浅深度的高分辨率成像和低分辨率的深层组织成像。使用该组合系统成功展示了在光学聚焦下横向分辨率为4 µm、成像深度为1.4 mm，以及在声学聚焦下横向分辨率为45 µm、成像深度为7.8 mm的结果。在此，进行了体内小动物血管成像以证明其生物成像能力。
