From the Guidelines
Dural venous sinus thrombosis can be diagnosed using imaging techniques, with Magnetic Resonance Imaging (MRI) being more sensitive than Computed Tomography (CT) 1.
Diagnostic Imaging
- MRI is preferred due to its ability to visualize the superficial and deep venous systems, define brain parenchyma, and detect early ischemic changes 1.
- CT can be used initially, especially in emergency situations, but it has limitations such as exposure to ionizing radiation and low resolution for small parenchymal abnormalities 1.
Key Features
- Imaging features suggesting venous infarction with hemorrhage may include atypical distributions not matching arterial vascular territories, infarcts with cortical sparing, typical parasagittal or temporoparietal location, or dural venous/cortical venous hyperdensity on noncontrast CT suggestive of thrombus 2.
- The presence of hypercoagulable risk factors (cancer, recent oral contraceptive use, and pregnancy) and symptoms such as headaches, seizures, or decreased level of consciousness can also aid in diagnosis [(2, 3)].
Surveillance Imaging
- In patients with known venous sinus thrombosis, surveillance imaging is recommended to assess for recanalization of the occluded cortical vein/sinuses and to monitor for complications such as dural arteriovenous fistula 3.
From the Research
Diagnosis of Dural Venous Sinus Thrombosis
To diagnose dural venous sinus thrombosis (DVST), several imaging modalities and techniques can be employed. The choice of method depends on the clinical presentation, availability of resources, and the need for urgent diagnosis.
- Imaging Modalities: + Non-enhanced computed tomography (CT) can show hyperdensity in the dural venous sinus, which is a direct sign of thrombosis, but it has low sensitivity 4. + Magnetic Resonance (MR) imaging, including MR venography, offers excellent contrast resolution and is considered the mainstay in the non-invasive diagnosis of DVST 5. + Point-of-care ultrasound has also been reported as a potential tool for diagnosing DST, although its use is less common and more research is needed to establish its efficacy 6.
- MR Sequences for DVST Evaluation: + The diagnostic performance of various MRI sequences with and without contrast enhancement has been assessed, showing that the 3D T1-weighted GRE CE sequence has statistically significantly greater diagnostic performance than other sequences 7. + T1-weighted CE, T2-weighted, and T2-weighted FLAIR sequences also demonstrate good diagnostic performance, but with varying degrees of sensitivity and specificity 7.
- Clinical and Imaging Predictors: + The presence of gas in the dural venous sinus after blunt head trauma increases the likelihood of DVST, and finding a combination of gas and increasing density in the DVS on non-enhanced CT can be a practical method for early diagnosis 4. + A venous collateral scale (VCS) that grades alternative drainage routes may help predict clinical deterioration in patients with DVST, with lower VCS scores associated with a higher risk of clinical worsening 8.
Diagnostic Challenges
Diagnosing DVST can be challenging due to its variable presentation and the limitations of imaging modalities. Physiological variations, the evolution of thrombi, and incorrect selection or application of MR techniques can lead to false-positive and false-negative interpretations, impacting patient management and outcome 5. Therefore, a comprehensive approach that includes clinical evaluation, appropriate imaging techniques, and consideration of patient-specific factors is crucial for accurate diagnosis and effective management of DVST.