RT Journal Article SR Electronic T1 Extra- to intracranial arterial anastomoses in therapeutic embolization: recognition and role. JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 71 OP 75 VO 1 IS 1 A1 H S Ahn A1 C W Kerber A1 Z L Deeb YR 1980 UL http://www.ajnr.org/content/1/1/71.abstract AB Anastomoses from extra- to intracranial vessels have been shown in normal patients and, more commonly, in patients with arteriosclerotic occlusive disease, arteriovenous malformation, and postligation of the carotid artery. These channels may be of clinical importance during therapeutic embolization and probably account for two cases of complication, posterior fossa strokes that occurred after blockage of occipital arteries. By identifying these channels and then monitoring the ever-decreasing vessel acceptance of contrast agent and emboli, patient safety may be enhanced.