Instrumentation and Technology for Multiparametric Mapping of Intraparenchymal Circulation in the Brain Cortex

Abstract

The intraparenchymal distribution pattern of erythrocytes and plasma should certainly interact with the oxygen supply and energy balance in tissue microareas. To enhance our knowledge of how this interaction takes place in the brain cortex, a non-destructive videophotometric method has been developed. The current state of this method has evolved through a number of intermediate steps 1, 2, 3, 4, 5 representing an interplay between the actual level of understanding of how microcirculation can be assessed by intraparenchymal indicator-dilution and the level of instrumentation and technology available to do quantitative spatial imaging as the means of detecting intraparenchymal indicator dilution from capillary beds of the intact brain cortex. The latter has always been a limiting factor in achieving the ultimate goal of obtaining high resolution maps of local erythrocyte and plasma volumes, mean transit times, volume flows, local tube and discharge hematocrit, blood volume and flow in a repeatable manner. The purpose of this paper is to present the current state of instrumentation and technology that has made multiparametric assessment of cerebrocortical circulation for these parameters possible at a spatial resolution of 10000 sites/10 mm².