Journal of Ultrasound in Medicine, Vol 13, Issue 11 887-893, Copyright © 1994 by American Institute of Ultrasound in Medicine
Experimental and numerical models of acute intracranial hypertension and basilar artery blood flow velocity
P. P. Vieyres, J. M. de Bray, J. L. Saumet, F. Patat and L. Pourcelot
Laboratoire de Vision Robotique, I.U.T. Bourges, France.
A numerical model based on Navier-Stokes equations was used in conjunction
with an experimental model in rabbits to study the effects of acute
intracranial hypertension on basilar artery blood flow velocity. The
hypertension was induced by pressure transmission via an epidural pressure
sensor inserted into a parietal intracranial opening. A critical value of
half of the diastolic arterial pressure for the intracranial cerebral
pressure was determined by both numerical and experimental models. At this
intracranial cerebral pressure level, the total input resistance and total
input compliance, determined by the numerical model, exhibited an increase
of 27% and 10%, respectively, and the tissular compliance a decrease of 25%
from their physiologic baseline values. When the intracranial cerebral
pressure reaches the level of the diastolic arterial pressure, a zero
diastolic flow is observed into the cerebral vascular system. This study
validates the theoretical model, which could be used in assessing
intracranial cerebral pressure noninvasively in humans when O2 pressure can
be stabilized.
