1550 Nm Optical Coherence Tomography for In Vivo Deep Brain Cerebral Blood Flow Imaging

Employing longer wavelengths in optical microscopic imaging is recognized for its advantage in deep penetration. However, the 1550 nm spectrum band is often overlooked due to water's high absorption coefficient. This study investigates the feasibility of 1550 nm center wavelength-based optical coherence tomography (OCT) for imaging the cerebral vasculature and blood flow in the mouse brain cortex. In comparison to a commercial 1310 nm OCT system, the 1550 nm OCT system exhibits greater attenuation in deeper regions while yielding similar results in blood flow imaging across the entire cortex layers. Given the widespread use of the 1550 nm wavelength band in the communication industry, the associated costs for light sources, linear cameras, and optic components are relatively lower than those of the 1310 and 1700 nm bands. Therefore, the 1550 nm band OCT could be a favorable choice for imaging deep brain cerebral hemodynamics.