Spinal epidural arteriovenous fistulas (SEAVFs) are rare types of spinal arteriovenous fistulas consisting of a connection between a distal branch of the spinal arteries and the epidural venous plexus. These fistulas cause venous engorgement, and reflux into perimedullary veins leads to spinal congestive myelopathy. The common and less invasive method to identify spinal arteriovenous fistulas is magnetic resonance angiography (MRA), and especially time-resolved MRA (TR-MRA) is desirable because it can achieve a high enough temporal resolution to image the flow dynamics of the shunt and associated vessels. Due to the rarity of the disease, the effectiveness of TR-MRA in diagnosing SEAVFs has not been well reported. In our case, a 74-year-old female patient presented with a one-week history of progressive gait disturbance and urinary incontinence. Magnetic resonance T2-weighted images of the thoracolumbar spine revealed an intramedullary hyperintensity signal area in the spinal cord with slight perimedullary flow voids. The arterial phase of TR-MRA showed an enlarged epidural venous pouch and a refluxing radicular vein supplied by branches from the right segmental arteries of T12 and L1. These findings led to the correct diagnosis of SEAVF with congestive myelopathy. The presence of arterialized epidural venous pouches is a decisive finding of SEAVFs. Our case suggests that TR-MRA can visualize these arterialized fistulas and contribute to the diagnosis of SEAVFs.
Nagawa et al. (2026) studied this question.