What is the grading of dural venous sinus stenosis in radiology?

From the Guidelines

Dural venous sinus stenosis is typically graded using a percentage-based system that quantifies the degree of narrowing in the affected venous sinus, with the most commonly used grading system categorizing stenosis as mild (0-50% narrowing), moderate (50-75% narrowing), or severe (>75% narrowing) 1.

Grading System

The grading system is based on the percentage of luminal narrowing, with the location of stenosis, presence of collateral vessels, and pressure gradients also being important factors to consider.

• The location of stenosis is most commonly the transverse sinus.
• The presence of collateral vessels can affect the clinical significance of the stenosis.
• Pressure gradients across the stenotic segment can be measured using digital subtraction angiography (DSA), with a pressure gradient of >8-10 mmHg considered hemodynamically significant.

Radiological Assessment

Radiological assessment is primarily performed using magnetic resonance venography (MRV), computed tomography venography (CTV), or DSA, with DSA considered the gold standard due to its superior spatial resolution and ability to measure pressure gradients across stenotic segments 1.

• MRV is used to diagnose and follow cortical vein and dural venous sinus thrombosis and is typically performed in conjunction with anatomic MRI without and with IV contrast.
• CTV is an alternative to MRV, but may not provide the same level of detail.
• DSA is considered the gold standard due to its ability to measure pressure gradients and provide high-resolution images of the venous sinuses.

Clinical Significance

The clinical significance of stenosis must be correlated with symptoms and intracranial pressure measurements, as anatomical narrowing doesn't always cause pathology 1.

• Severe stenosis (>75%) is more likely to benefit from interventional procedures like stenting, particularly when associated with significant pressure gradients and clinical symptoms such as intractable headaches or visual disturbances in idiopathic intracranial hypertension.
• The grading system helps guide treatment decisions, with the goal of improving morbidity, mortality, and quality of life for patients with dural venous sinus stenosis.

From the Research

Dural Venous Sinus Stenosis Grading

• Dural venous sinus stenosis is a condition that can lead to idiopathic intracranial hypertension (IIH) 2, 3, 4.
• The grading of dural venous sinus stenosis is not explicitly mentioned in the provided studies, but the studies discuss the importance of identifying and treating the condition to alleviate symptoms of IIH 2, 3, 4.

Radiology and Diagnosis

• Multimodal imaging methods, including MRI and digital subtraction angiography, can be used to investigate dural venous sinus stenosis and identify anatomical variations 5.
• MR venography can provide essential information on anatomical variation and morphological or functional change of the offending dural venous sinus 5.
• Cerebral angiography can be used to diagnose and treat dural venous sinus stenosis 2, 3, 4.

Treatment and Outcomes

• Dural venous sinus stenting has emerged as a treatment option for medically refractory IIH with venous sinus stenosis 2, 3, 4.
• The technical success rate of dural venous sinus stenting is high, with low complication rates 2, 3.
• Symptom relief, including improvement in headache and visual symptoms, can be achieved in a majority of patients undergoing dural venous sinus stenting 2, 3, 4.
• Stent patency rates and re-stenosis rates vary, with one study reporting a stent patency rate of 81.8% and a re-stenosis rate of 18.2% 3.