Biomedical Engineering Reference
In-Depth Information
Fig. 22.1
CSF circulates through the four brain ventricles and in the subarachnoid space surround-
ing the brain and spinal cord. Most of the CSF is reabsorbed into the venous system through the
arachnoid granulations and through the walls of the capillaries of the central nervous system and
pia mater
flow patterns arising from the source of production within the patient-specific ven-
tricular system.
A particular drawback of the majority of existing CSF transport models is the
conflation of the cerebral blood network and the CSF. In comparison, MPET allows
an elegant and novel extension of traditional poroelastic models to include detailed
transfer mechanisms between the cerebral blood and extracellular fluid/CSF. The
novelty of this approach leads to both a strength and a challenge, as many of the
requisite material properties have never been recorded. Previous parametric studies
(Tully and Ventikos,
2011
) have identified both healthy and symptomatic ranges for
these newly introduced parameters.
22.2 Background
22.2.1 Background to Cerebral Anatomy
Figure
22.1
illustrates a sagittal cut of the cranial area under consideration. As can
be seen, the cerebral ventricles are the major CSF-containing spaces. It is known
that when considering adults, the normal CSF circulation proceeds in a consistent
and uniform manner. The classical hypothesis of CSF transport through the ventri-
cles involves the production of CSF at the Choroid Plexuses of the lateral, third and
fourth ventricles. CSF then flows out of the lateral ventricles via both the foram-
ina of Monro and into the third ventricle. From there, CSF passes into the fourth
ventricle via the aqueduct of Sylvius. The foramen of Magendie and the bilateral
