Assessment of dural arteriovenous fistulas of the cavernous sinuses on 3D dynamic MR angiography

Abstract

Background and purpose: Flow voids within the cavernous sinuses and/or certain venous drainage on spin-echo MR imaging and time-of-flight (TOF) flow enhancement on MR angiography (MRA) have indicated high-velocity shunt flow and have been used for screening patients with dural arteriovenous fistulas (DAVFs) of the cavernous sinuses. In this investigation, the capabilities of 3D dynamic MRA as a flow-independent approach and those of conventional MR imaging techniques were compared with selective angiography for the diagnosis of DAVFs of the cavernous sinuses.

Materials and methods: This retrospective study involved 18 patients with angiographically proved DAVFs of the cavernous sinuses and 12 control subjects. Sixteen partially overlapping sequential MR images were acquired on contrast-enhanced 3D dynamic MRA between the petrosal bone and the orbital roof. Two experienced observers blinded to the clinical data and results of angiography independently graded 3D dynamic MRA, fast spin-echo T2-weighted imaging (FSE T2WI), and TOF MRA.

Results: The average area under the receiver operating characteristic curve values and interobserver kappa scores for the diagnosis of DAVFs on 3D dynamic MRA, FSE T2WI, and TOF MRA were 0.99, 0.89, and 0.95; and 0.92, 0.71, and 0.73, respectively. Those for the diagnosis of anterior, posterior, and retrograde cortical venous drainage on 3D dynamic MRA were 0.72, 0.95, and 0.81; and 0.56, 0.50, and 0.49, respectively.

Conclusion: In this small series, screening 3D dynamic MRA directly demonstrates DAVFs of the cavernous sinuses and has improved diagnostic capability.

Fig 1.

A 52-year-old woman presenting with proptosis and chemosis in the right orbit and 2 months of diplopia resulting from anterior draining DAVFs of the right cavernous sinus. Subtracted maximum-intensity-projection images on 3D dynamic MRA. A and B, Early venous enhancement is demonstrated within the right cavernous sinus and superior ophthalmic vein in the arterial-dominant phase (A) and is more clearly identified in the next phase (B). C, The venous structures are visualized by normal venous return in the arteriovenous phase.

Fig 2.

A 65-year-old woman with left frontal pain and diplopia for 1 month without congestive orbito-ocular features resulting from DAVFs of the left cavernous sinus. Reversed source sectional images in the arterial-dominant phase on 3D dynamic MRA. A and B, Early venous enhancement is demonstrated within the bilateral inferior petrosal sinuses, basilar plexus, left pterygoid plexus (A), and left cavernous sinus (B). C, In addition, retrograde cortical reflux to the left sphenoparietal sinus is a clinically important feature.

Fig 3.

A diagnostic flow chart of DAVFs of the cavernous sinuses.