Contrast agent induced obliteration of a spinal arteriovenous malformation

We present a patient undergoing spinal angiography and suspected of having an AVM. During the first injection of nonionic contrast, a nidal AVM supplied by the great anterior radiculomedullary artery at T9 left was found. The second injection at T9 left no longer showed the contrast filling of the AVM. Follow-up angiography showed persistent AVM obliteration with an intact arterial spinal axis. The patient's symptoms resolved. Interaction between nonionic contrast, blood, and vessel wall most likely induced the obliteration.