Spontaneous thrombosis of a vein of Galen aneurysmal malformation: possible effects of contrast media

A 5-year-old boy with macrocephaly and mental retardation was referred for radiologic evaluation. After cranial CT and MR imaging, the diagnosis of mu ral type vein of Galen aneurysmal malformation was established by angiograp hy. Two weeks later, preembolization angiography revealed complete thrombos is of the malformation. Although it is a very rare event, vein of Galen ane urysmal malformation may spontaneously thrombose following diagnostic angio graphy. Possible effects of contrast media on thrombosis were discussed.