Journal of Ultrasound in Medicine, Vol 5, Issue 7 365-372, Copyright © 1986 by American Institute of Ultrasound in Medicine
The fetal subarachnoid cisterns: an ultrasound study with report of a case of congenital communicating hydrocephalus
G. Pilu, L. De Palma, R. Romero, L. Bovicelli and J. C. Hobbins
The intracranial anatomy of 351 normal fetuses, ranging from 15 to 42
weeks' gestational age, was investigated sonographically in an attempt to
define the normal sonographic anatomy of the subarachnoid spaces during
intrauterine development. The triangular velum, vein of Galen, ambient,
interpeduncular, chiasmatic, Sylvian, and supracerebellar cisterns and the
cisterna magna were easily recognized in the vast majority of cases as
fluid-filled spaces following the contour of the brain. A large fluid
layer, overlying the cerebral convexities, was seen in early gestation and
subsequently disappeared. Evaluation of the subarachnoid cisterns in a
fetus with ventriculomegaly allowed the prenatal diagnosis of communicating
hydrocephalus. Knowledge of the normal sonographic anatomy of the
subarachnoid spaces is useful both in avoiding misinterpretation of the
normal sonogram and in the differential diagnosis of congenital
hydrocephalus.
