"type I: small pure cisternal fistula between the vein of Galen (voG) and either the pericallosal arteries (anterior or posterior) or posterior cerebral artery"
"type II: multiple fistulous communications between the vein of Galen and the thalamoperforating vessels"
"type III: high flow mixed type I and II"
"type IV: parenchymal arteriovenous malformation (AVM) with drainage into the vein of Galen"
Expected headings
"See also"