MRI of hydrocephalus and CSF velocity imaging

Abstract

Cerebrospinal fluid (CSF) is produced at a rate of 500 ml/day by the choroid plexus within the ventricular system [1]. Normally, it flows out the foramina of Lushka and Magendie of the fourth ventricle into the subarachnoid space (SAS). From there, the CSF normally flows up over the convexities to be absorbed by the arachnoidal granulations and villi on either side of the superior sagittal sinus (Fig. 46.1). Obstruction to the outflow of CSF leads to back up and ventricular enlargement or “hydrocephalus” [2]. If the obstruction is between the choroid plexus and the outlet foramina of the fourth ventricle, it is called “obstructive” hydrocephalus.