Laser Scanning Methodologies for Measuring RBC Velocity, Flux, Hematocrit and Shear Rate in Vascular Networks

Abstract

There are many normal and pathological processes that alter blood flow in a vascular network including thermal regulation, infarction, wounding and neoplasia. Flow changes caused by formation or loss of vascular connections and modulation of vessel diameters can dramatically affect nutrient and drug delivery, but these changes are poorly understood at the level of individual vessel segments and their connected neighborhood. To address this problem, we developed methodology for quantifying blood flow (velocity, flux and hematocrit) in extended networks at the single capillary level. Our approach relies on deconvolution of signals produced by labeled red blood cells as they move relative to the scanning laser of a confocal or multiphoton microscope, and provides fully-resolved three-dimensional flow profiles within tumor vessels. This methodology has sufficient spatiotemporal resolution for extracting blood velocity profiles in vivo and can be used to detect changes in blood vessel classification based on function.

This chapter is derived from Kamoun et al., Nat Methods 2010. Figures have been reproduced here with permission.