Accuracy of DynaCT Venogram Compared to Digital Subtraction Venography for Evaluation of Dural Sinus Stenosis

Purpose: Transverse sinus stenting has become increasingly accepted as a potential treatment for idiopathic intracranial hypertension. However, because of the still small number of cases performed worldwide, the optimal imaging approach for evaluation of dural sinus stenosis amenable to angioplasty and stenting is not yet defined. We evaluated the accuracy of DynaCT venogram compared with routine biplane digital subtraction venogram (DSV) for evaluation of transverse sinus stenosis in patients presenting with symptomatic intracranial hypertension.

Materials and Methods: We identified 26 patients who presented with idiopathic intracranial hypertension and subsequently underwent successful transverse sinus stenting at our institution between 2012 and 2019. Each patient’s preoperative biplane DSV was retrospectively reviewed in conjunction with her or his DynaCT venogram, and the rates of identification of significant stenosis using each modality were compared. Dural venous sinus intravascular manometry was also performed in a majority of the patients to assess for pressure gradient across the stenoses.

Results: Twenty-six patients (21 female, 5 male; mean age, 37.0 years) were found to have significant focal stenosis in the right, left, or bilateral transverse sinuses. Of the total 30 stenotic sites, 21 stenoses were identifiable on biplane DSV versus 29 seen on DynaCT venography, for an identification rate of 70% in the former versus 97% in the latter (P <0.01). No stenosis was identified only on biplane DSV but not seen on DynaCT venography. One was not seen on either modality. All patients who underwent manometry demonstrated significant pressure gradient across the stenoses (mean gradient, 14.7 mm Hg.) There were no immediate complications associated with the use of DynaCT venography in addition to the biplane DSV.

Conclusions: DynaCT and DynaCT angiography are frequently used in neuroendovascular procedures to improve patient outcomes. However, their utility for evaluation of dural sinus stenosis has not been well-established. Our study showed that DynaCT venography provides improved rate of identification of focal, hemodynamically significant stenosis amenable to treatment compared to biplane DSV at a rate comparable to intravascular manometry, with additional benefit of improved characterization of the lesions and more accurate selection of proper stent size.