The cerebral aqueduct, also known as the aqueductus mesencephali, mesencephalic duct, or the aqueduct of Sylvius is within the mesencephalon (or midbrain), contains cerebrospinal fluid (CSF), and connects the third ventricle in the diencephalon to the fourth ventricle within the region of the mesencephalon and metencephalon, located dorsal to the pons and ventral to the cerebellum.
SA: Aqueduct of Sylvius
The aqueduct of Sylvius is the channel which connects the third ventricle to the fourth ventricle and is the narrowest part of the CSF pathway with a mean cross-sectional area of 0.5 mm2 in children and 0.8 mm2 in adults.
see Aqueductal tumor.
MR imaging has been proposed to quantify the flow of CSF in the aqueduct.
By phase contrast magnetic resonance imaging (PCCMR), the stroke volume (SV), defined as the mean volume passing through the aqueduct during both systole and diastole, can be calculated. A SV greater than or equal to 42 μL serves as a selection criterion for patients with good probabilities of improvement after VPS.