Intradural spinal varix: the "doughnut" sign on T 2 weighted MR and confirmation with gadolinium-enhanced arterial and blood pool MR angiography.

Intradural spinal varices are rare lesions, with only three cases being previously reported in the literature. Previously described patients underwent MRI for non-specific low back pain and radiculopathy and were found to have an intradural lesion adjacent to the cauda equina, mimicking a nerve sheath tumour or ependymoma. Consideration of an intradural varix in the differential diagnosis of an intradural extramedullary spinal lesion is necessary to guide appropriate management. We report a case of an intradural spinal varix diagnosed with first-pass arterial and blood pool phase gadolinium - enhanced auto-triggered elliptic centric-ordered MR angiography. Digital subtraction angiography confirmed that there was no shunt but failed to demonstrate the varix. We reviewed the existing literature to look for common clinical and imaging features.