Can we rule out a spinal arteriovenous fistula using only MRI?

Spinal arteriovenous fistulae (SAVF), including spinal dural arteriovenous fistulae and perimedullary fistulae, produce a progressive myelopathy due to venous hypertension and spinal cord congestion.1 They generally present with back and leg pain, worsening (typically ascending) leg weakness and sensory changes, exertional claudication, and symptoms of bladder dysfunction.2 This semiology can lead clinicians to suspect other more common disorders, such as peripheral neuropathy, multiple radiculopathies, or spinal canal stenosis.3 In fact, erroneous consideration of these other diagnoses often causes a delay in the identification and treatment of SAVF.2 This is an important problem because treatment of the fistula (by disconnecting the arterialized vein by open surgery or endovascular therapy) can improve symptoms and is highly effective in preventing progression of disability.4,5 Thus, although the prevalence of SAVF is low, clinicians need to a have a low threshold to consider this treatable diagnosis.