Microscopic imaging of cerebral blood flow with optical coherence tomography

This presentation will introduce three techniques that we have recently developed for microscopic imaging of cerebral blood flow (CBF) in both large vessels and capillaries. The techniques are based on optical coherence tomography (OCT). First, we integrated OCT with dynamic light scattering analysis, enabling us to measure both axial and transverse velocities at every voxel of OCT. Meanwhile, as red blood cells (RBCs) flow one by one in capillaries, the traditional decorrelation-based methods may not be suitable for quantifying the RBC flow properties of capillaries. Here, we developed another technique based on the finding that individual RBC passage can be captured in the OCT intensity signal time course. This technique enabled volumetric estimation of capillary RBC speed, flux, and density. Finally, we developed the third technique for rapid volumetric imaging of RBC flux over a capillary network, with a high temporal resolution of ~1 s that is essential for tracing fast hemodynamic responses.