Variable filling of an arteriovenous malformation during carotid angiography. A case report.

An 11-year-old girl was operated on for a frontal arteriovenous malformation in 1978; a postoperative carotid angiogram showed no filling of the AVM. The patient still had epilepsy. In 1981 a carotid angiogram showed no AVM. Some months later a new carotid angiography was done. In the first lateral series no AVM was seen but on the second injection with one more millilitre of contrast medium a large frontal AVM became apparent. The reasons for such variable filling are discussed.