Fig 2.

9-year-old girl with hydrocephalus and hydromyelia.

A and B, Axial contrast-enhanced CT scans of the brain show dilatation of the lateral, third, and fourth ventricles. There is suspicion of a cystic lesion (arrow in B) in the fourth ventricle. MR ventriculography was performed to study the intraventricular CSF flow and to delineate the fourth ventricle.

C, Axial MR ventriculogram after injection of gadodiamide into the right lateral ventricle shows contrast material layered in the dependent portion of the right lateral ventricle (arrow) and no contrast material in the left lateral ventricle.

D, Coronal MR ventriculogram after injection of gadodiamide into the right lateral ventricle shows contrast material limited to the body and temporal horn of the right lateral ventricle (arrow). There is minimal contrast material in the third ventricle, suggesting a partial block in the right foramen of Monro.

E, Sagittal MR ventriculogram after injection of contrast material into the right lateral ventricle shows minimal contrast material entering the third and fourth ventricles. Note the presence of a syringomyelia in the upper cervical cord (arrow).

F, Axial MR ventriculogram through the bodies of the lateral ventricles. Contrast material was injected into the left lateral ventricle 100 minutes after the previous injection into the right lateral ventricle. This image shows a more uniform distribution of the contrast material in the right lateral ventricle, with no evidence of layering.

G, Coronal MR ventriculogram after injection of contrast material into the left lateral ventricle shows good flow of the contrast material through the left foramen of Monro into the third ventricle.

H, Sagittal MR ventriculogram shows flow of contrast material from the third ventricle into the fourth ventricle with no intraventricular lesion. The syrinx in the upper cervical cord (arrow) is again noted.