Acute medullary syndrome developed in a patient in whom glue had been inadvertently injected into the right posterior radiculomedullary artery during endovascular occlusion of a spinal dural arteriovenous fistula at T-11. MR imaging 40 days after the procedure showed signal changes and contrast enhancement in the posterior and right lateral column at T10-11. Circumscribed signal changes in the same areas without contrast enhancement were seen 4 months later. MR imaging was able to show this posterior spinal artery infarct.