Professor Kevin K.M. Tsai, Professor of Department of Electrical and Electronic Engineering had worked on research for the topic “Ultrafast two-photon fluorescence imaging of cerebral blood circulation in the mouse brain in vivo”. The research has been published by PNAS on June 1, 2022.
Details of the publication:
Ultrafast two-photon fluorescence imaging of cerebral blood circulation in the mouse brain in vivo
Guanghan Meng, Jian Zhong, Qinrong Zhang, Justin S. J. Wong, Jianglai Wu, Kevin K. Tsia, and Na Ji, Article in PNAS, https://www.pnas.org/doi/abs/10.1073/pnas.2117346119
Characterising blood flow dynamics in vivo is critical to understanding the function of the vascular network under physiological and pathological conditions. Existing methods for hemodynamic imaging have insufficient spatial and temporal resolution to monitor blood flow at the cellular level in large blood vessels. By using an ultrafast line-scanning module based on free-space angular chirped enhanced delay, we achieved two-photon fluorescence imaging of cortical blood flow at 1,000 two-dimensional (2D) frames and 1,000,000 one-dimensional line scans per second in the awake mouse. This orders-of-magnitude increase in temporal resolution allowed us to measure cerebral blood flow at up to 49 mm/s and observe pulsatile blood flow at harmonics of heart rate. Directly visualising red blood cell (RBC) flow through vessels down to >800 µm in depth, we characterised cortical layer–dependent flow velocity distributions of capillaries, obtained radial velocity profiles and kilohertz 2D velocity mapping of multifile blood flow, and performed RBC flux measurements from penetrating blood vessels.