Introduction: A certain percentage of patients with idiopathic intracranial hypertension (IIH) have venous sinus stenosis. A number of patients are undergoing interventional evaluation of stenosis with venography and manometry in consideration for stenting. MRV is used in the diagnosis of cerebral sinus thrombosis but little literature exists regarding its reliability when compared to the “gold standard” DSV. The purpose of this study was to study the reliability of MRV and determine its sensitivity and specificity.
Methods: So far, nineteen patients with the diagnosis of IIH who were evaluated with an MRV and DSV were included in the study. MRV images were reviewed by two Radiologists who scored DVSS as very mild, mild, moderate, or severe based on percentage stenosis <25%, 25-50%, 50-75%, >75%, respectively. The percent stenosis and manometry results were obtained from DSV on each patient for comparison.
Results: The inter-observer reliability for stenosis greater than 50% (moderate/severe) of the MRV evaluations is 80%. The sensitivity and specificity of MRV as compared to DSV for greater than 50% stenosis is 100% and 11%, respectively. The degree of stenosis on venography was plotted against pressure gradient obtained at the time of venography. The linear correlation coefficient is r = +0.53 p-value (0.0089).
Conclusions: Upon calculation of our results thus far, MRV appears to have a high sensitivity but poor specificity as compared to angiogram for DVSS > 50%. The inter-observer reliability of only 80% demonstrates that these scans are most helpful when evaluated by a Radiologist familiar with the studies. The low but positive correlation between angiographic stenosis and pressure gradient demonstrates that even patients with stenosis <50% may be candidates for stenting and manometry may be a better gold standard for future DVSS studies.
Patient Care: It will prove that more patients with the diagnosis of IIH should undergo interventional manometry to rule out significant DVSS causing a pressure gradient before considering the treatment of stenting. After further studies evaluating the most appropriate pressure gradient instead of percentage stenosis on imaging will help ensure patients receive treatments that have a better opportunity for helping them. As important, patients without significant pressure gradients will not undergo interventional stenting procedures requiring dual anti-platelet therapy.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the utility of MRV when evaluating a patient for IIH. 2) Discuss the need for sinus manometry for full evaluation of DVSS as related to IIH patients. 3) Identify that MRV exams should be evaluated by an experienced practitioner when considering DVSS.