Mario Mascalchi, MD, PhD Giampiero Ferrito, MD Nello Quilici, MD Salvatore Mangiafico, MD Mirco Cosottini, MD Martino Cellerini, MD Letterio S. Politi, MD Laura Guerrini, MD Carlo Bartolozzi, MD Natale Villari, MD Index terms: Arteriovenous malformations, spinal, 30.149 Arteriovenous malformations, therapeutic embolization, 30.1264 Magnetic resonance (MR), vascular studies, 30.121411, 30.12142, 30.12143 Spinal cord, abnormalities, 30.149 Spinal cord, blood supply, 30.149 Spinal cord, MR, 30.121411, 30.12142, 30.12143 Radiology 2001; 219:346 –353 Abbreviations: DSA = digital subtraction angiography 3D = three-dimensional 2D = two-dimensional 1 From the Department of Clinical Pathophysiology, Section of Radiodi- agnostics, University of Florence, Viale Morgagni 85, 50134 Florence, Italy (M.M., M. Cellerini, L.S.P., L.G., N.V.); Department of Neuroradiology, Hos- pital Riuniti, Livorno, Italy (G.F., N.Q.); Department of Neuroradiology, Hos- pital of Careggi, Florence, Italy (S.M.); and Department of Radiology, Univer- sity of Pisa, Italy (M. Cosottini, C.B.). Received April 25, 2000; revision re- quested June 12; revision received July 28; accepted August 30. Address cor- respondence to M.M. © RSNA, 2001 Author contributions: Guarantor of integrity of entire study, N.V.; study concepts and design, M.M.; literature research, L.S.P.; clinical stud- ies, G.F., S.M.; data acquisition, M. Co- sottini, M. Cellerini, G.F., N.Q.; data analysis/interpretation, M.M., M. Co- sottini; manuscript preparation, L.G.; manuscript definition of intellectual content and editing, M.M.; manuscript revision/review, C.B.; manuscript final version approval, N.V. Spinal Vascular Malformations: MR Angiography after Treatment 1 PURPOSE: To evaluate the role of magnetic resonance (MR) angiography in the assessment of spinal vascular malformation therapy. MATERIALS AND METHODS: Thirty-four patients with spinal vascular malforma- tions (30 dural arteriovenous fistulas, two perimedullary arteriovenous fistulas, and two intramedullary arteriovenous malformations) underwent MR angiography and MR imaging before and after endovascular or surgical treatment. RESULTS: MR angiography showed residual flow in perimedullary vessels in seven patients with dural fistula after embolization with liquid adhesive. In all seven, treatment failure was confirmed with arteriography. Long-lasting disappearance of flow in peri- medullary vessels was demonstrated at MR angiography in 22 patients with dural fistula. MR imaging demonstrated normalization of spinal cord volume in 16 of 22 patients and signal intensity on T2-weighted images in three patients. Disappearance of cord enhancement was observed in five of 21 patients and of perimedullary enhanced vessels in six of 13 patients. In one additional patient with dural fistula treated with embolization, early posttreatment MR angiography showed disappearance of flow in perimedullary vessels, which reappeared at follow-up and was consistent with reopen- ing of a small residual fistula. Posttreatment MR angiography demonstrated transient reduction of flow in the nidus in two patients with intramedullary malformations treated with embolization. Permanent disappearance of flow in the perimedullary vessel was seen after endovascular treatment in two patients with perimedullary fistula. CONCLUSION: MR angiography is more sensitive than MR imaging in depicting residual or recurrent flow in peri- or intramedullary vessels, which indicates patency of the vascular malformation. Vascular malformations are a treatable cause of myelopathy. Magnetic resonance (MR) angiography is a useful complement to MR imaging for detection and characterization of spinal vascular malformations before digital subtraction angiography (DSA) (1– 6). To our knowledge, the role of MR angiography in the evaluation of endovascular or surgical treatment of these lesions has not been thoroughly investigated. The purpose of our study was to report posttreatment MR angiographic and MR imaging findings in 34 patients with spinal vascular malformations. MATERIALS AND METHODS From April 1992 to February 2000, 34 patients (10 women, 24 men; age range, 18 – 84 years) with native spinal vascular malformations underwent 122 spinal MR examinations before (n = 46) and after (n = 76) treatment in three centers (University of Florence; University of Pisa; Hospital Riuniti, Livorno, Italy) as a part of our routine evaluation. All MR examinations included MR angiographic and MR imaging acquisitions. Selective DSA was performed within 2 weeks after pretreatment MR examination; DSA diagnosis (7,8) included spinal dural arteriovenous fistula (n = 28) and dural arteriovenous fistula at the cranial-cervical junction (n = 2) with perimedullary venous drainage in 30 patients, as well as intradural arteriovenous malformations in four patients. The latter comprised two cases of intramedullary arteriovenous malformations of a glomus type and one case each of a Neuroradiology 346