Opt Lett. 2022 Mar 1;47(5):1121-1124. doi: 10.1364/OL.450648.
Optical resolution photoacoustic microscopy (OR-PAM) can map the cerebral vasculature at capillary-level resolution. However, the OR-PAM setup's bulky imaging head makes awake mouse brain imaging challenging and inhibits its integration with other optical neuroimaging modalities. Moreover, the glass cranial windows used for optical microscopy are unsuitable for OR-PAM due to the acoustic impedance mismatch between the glass plate and the tissue. To overcome these challenges, we propose a lithium niobate based transparent ultrasound transducer (TUT) as a cranial window on a thinned mouse skull. The TUT cranial window simplifies the imaging head considerably due to its dual functionality as an optical window and ultrasound transducer. The window remains stable for six weeks, with no noticeable inflammation and minimal bone regrowth. The TUT window's potential is demonstrated by imaging the awake mouse cerebral vasculature using OR-PAM, intrinsic optical signal imaging, and two-photon microscopy. The TUT cranial window can potentially also be used for ultrasound stimulation and simultaneous multimodal imaging of the awake mouse brain.
光学分辨光声显微镜（OR-PAM）可以以毛细血管水平的分辨率绘制脑血管图。然而，OR-PAM 设备庞大的成像头使得在清醒的老鼠大脑中进行成像具有挑战性，并抑制了其与其他光学神经影像学模式的整合。此外，用于光学显微镜的玻璃颅窗由于玻璃板和组织之间的声阻抗不匹配，不适合 OR-PAM。为了克服这些挑战，我们提出了一种基于铌酸锂的透明超声换能器（TUT）作为薄化鼠颅骨上的颅窗。由于 TUT 颅窗具有光学窗和超声换能器的双重功能，因此大大简化了成像头。该窗稳定了六周，没有明显的炎症和最小的骨再生。通过使用 OR-PAM、固有光学信号成像和双光子显微镜对清醒老鼠的脑血管进行成像，证明了 TUT 颅窗的潜力。TUT 颅窗还可用于对清醒老鼠大脑进行超声刺激和同时进行多模态成像。
