Biomedical Engineering Reference
In-Depth Information
Fig. 22.2
(
Left
): Axial view of geometry of a human ventricular system showing key anatomical
features. (
Right
): View of the ventricular system along with the choroid plexus of the lateral, third
and fourth ventricle. The arteries supplying these plexuses are also shown
foramina of Luschka act as the final outlets of the CSF leading to the subarachnoid
space. The central canal of the spinal cord also receives CSF from the fourth ventri-
cle; however, in comparison to the foramen of Luschka and foramina of Magendie,
this is a minute quantity. Once the CSF has exited from the cerebral ventricular sys-
tem, it accumulates in the subarachnoid cisterns surrounding the brainstem (cisterna
magna, medullary, pontine, interpeduncular, ambient and suprasellar cistern respec-
tively). The choroid plexus is the main site of CSF production and is situated within
the third, fourth and the underside of the lateral ventricles, see Figs.
22.1
and
22.2
.
CSF is also produced, to a lesser degree, within the bulk of the brain parenchyma
(Irani,
2009
). Once the CSF reaches the fourth ventricle, some of it exits through the
central canal but the overwhelming proportion flows around the tentorium cerebelli
in order for it to be absorbed by the arachnoid granulations and into the superior
sagittal sinus (Rekate,
2008
; Gupta et al.,
2010
).
Since this work will incorporate geometrically accurate choroid plexuses in all
the aforementioned locations, the arterial supplies to these plexuses have to be in-
cluded, see Fig.
22.2
. For the lateral ventricle, the arterial supply is dominated by
the anterior choroidal artery (ACA) and the medial and lateral posterior choroidal
arteries (MpCA and LpCA). Likewise, the choroid plexus of the third and fourth
ventricle is supplied by the posterior cerebral and inferior cerebellar arteries (PCA
and ICrA) respectively (Irani,
2009
).
22.2.2 Hydrocephalus (HCP)
HCP can be succinctly described as the abnormal accumulation (imbalance between
production and circulation) of CSF within the brain (Rekate,
2008
,
2009
). This bal-
ance of CSF production and reabsorption allows for the CSF pressure to lie within
