Vein of Galen malformation. Brain MRI: The measured diameter of the dilated median prosencephalic vein has slightly increased since the previous MRA examination. It measures maximally 18 mm in width compared to 13 mm previously. T1/T2-hypointense signal in in the inferior right side of the median prosencephalic vein on MR angiography relates to embolization of the feeder from the left posterior cerebral artery. Otherwise, the lumen shows heterogeneous signal, which may reflect partial thrombosis. The aneurysmal dilatation of the posterior segment of the superior sagittal sinus shows preserved flow-related signal void. The brain demonstrates appropriate for age myelination. Small foci of susceptibility artifacts, especially within the occipital horns of the bilateral lateral ventricles, reflect previous subarachnoid hemorrhage and are not changed. The ventricles and the other CSF-containing spaces are normal in size. There is no midline shift or mass-effect. Fluid signal in the right mastoid air cells can be congestive. Mucosal thickening in the paranasal sinuses and specific in this age and may represent normal, redundant mucosa.Cranial MRA: It shows the feeders from the left and right posterior cerebral arteries and the lack of significant feeders from the pericallosal arteries.
1.The median prosencephalic vein (vein of Galen aneurysmal malformation) has slightly increased in size since the previous examination. The heterogeneous luminal signal may reflect partial thrombosis. There are changes of previous embolization of the feeder from the left posterior cerebral artery. 2.The ventricles remain normal in size. The brain shows age-appropriate myelination.3.Minimal hemosiderin staining in the occipital horn of the lateral ventricles is unchanged.