SUMMARY:Arterialized blood flow in the cavernous sinus may result from carotid-cavernous fistula or dural venous fistula. We encountered an unusual case of arterialized blood flow in the cavernous sinus on MR angiography resulting from arterialized retrograde venous flow in the internal jugular vein. This abnormal flow originated from an upper extremity dialysis arteriovenous fistula in the presence of central venous occlusion. The patient's symptoms of visual disturbance resolved after the central venous occlusion was treated with stent placement.A 36-year-old woman with a history of end stage renal disease, dialysis dependence, and left-arm arteriovenous (AV) fistula was hospitalized with vague abdominal pain and possible bowel obstruction. After 7 days in the hospital, she reported blurriness of vision and eventually provided a history of intermittent visual blurriness and headaches during the past few weeks, as well as mild left-arm pain.Noncontrast MR imaging of the head revealed prominence of the left superior ophthalmic vein and mild left proptosis. Intracranial time-of-flight MR angiography (MRA) was also performed (Fig 1A). This showed abnormally increased signal intensity within the left cavernous sinus, the left transverse sinus, the left inferior petrosal sinus, and the ipsilateral superior ophthalmic vein. This signal intensity was interpreted as suggestive of carotid cavernous sinus fistula or dural venous fistula, and a catheter angiogram was recommended. A conventional cerebral angiogram was then performed. There was no evidence of carotid-cavernous fistula (CCF) (Fig 1B). Injection of the bilateral internal carotid, selective bilateral external carotid, and bilateral vertebral arteries all showed no evidence of dural venous fistula. Contrast injection of the aortic arch revealed normal great vessels, but the late arterial phase showed early flow into the left subclavian vein, as expected with AV fistula. Venous phase images showed that the left brachiocephalic vein was occluded and virtually the entire early left-sided venous contrast return flowed in a retrograde fashion through the left internal jugular vein (Fig 1C). Therefore, the arterialized intracranial venous flow was attributable to retrograde flow in the left jugular vein system.Recanalization of the left innominate vein and placement of a 12 ϫ 40 mm Wallstent (Boston Scientific, Natick, Mass) was then performed. Following recanalization, normal antegrade flow returned to the left jugular vein. Follow-up MR imaging was performed 5 months after recanalization (Fig 2). The study showed resolution of the abnormal signal intensity within the left cavernous sinus, petrosal sinus, and superior ophthalmic vein. There was some residual abnormal signal intensity present within the left transverse sinus, believed to represent persistent arterialized flow or partial thrombus formation. At the time of the follow-up scan, the patient's visual symptoms had resolved.