Interventional Neuroradiology: A Review

Measurement of sinus wall thickness and wall enhancement index in dural arteriovenous fistulae by magnetic resonance vessel wall imaging

BACKGROUND

Dural sinus wall thickness and wall enhancement index (WEI) of dural arteriovenous fistulae (DAVFs) have not been well characterized. This study aimed to measure the sinus wall thickness and WEI by using magnetic resonance vessel wall imaging (MR-VWI).

METHODS

A total 27 DAVF patients and 30 normal healthy individuals were enrolled in this study. All participants were scanned by a 3 T MR scanner with the black blood sequence. The wall thickness and the WEI of the great cerebral vein, the intracranial main dural sinuses with DAVFs, and the contralateral sinuses were measured by two independent neuroradiologists.

RESULTS

The DAVF-affected sinuses had significantly thicker walls (2.277 ± 0.311 mm vs. 1.446 ± 0.188 mm, P < 0.001) and significantly higher WEI (2.253 ± 0.462 vs. 1.173 ± 0.418, P < 0.001) compared to the contralateral ones. They also had significantly thicker walls (2.277 ± 0.311 mm vs. 1.643 ± 0.173 mm, P < 0.001) and significantly higher WEI (2.253 ± 0.462 vs. 1.124 ± 0.254, P < 0.001) compared to the normal controls. Neither the sinus wall thickness (r = -0.317, P = 0.107) nor the WEI (r = 0.019, P = 0.923) was significantly correlated with the Cognard types in DAVF patients. The WEI of the DAVF draining vein was significantly higher compared to the static venous wall (1.972 ± 0.629 vs. 0.532 ± 0.243, P < 0.001).

CONCLUSION

T1-CUBE MRI is useful in measuring sinus all thickness and WEI of DAVFs, providing a new method for diagnosing this disease.

Multimodal MRI diagnosis and transvenous embolization of a basicranial emissary vein dural arteriovenous fistula: A case report

A dural arteriovenous fistula (DAVF) is an abnormal linkage connecting the arterial and venous systems within the intracranial dura mater. A basicranial emissary vein DAVF drains into the cavernous sinus and the ophthalmic vein, similar to a cavernous sinus DAVF. Precise preoperative identification of the DAVF location is a prerequisite for appropriate treatment. Treatment options include microsurgical disconnection, endovascular transarterial embolization (TAE), transvenous embolization (TVE), or a combination thereof. TVE is an increasingly popular approach for the treatment of DAVFs and the preferred approach for skull base locations, due to the risk of cranial neuropathy caused by dangerous anastomosis from arterial approaches. Multimodal magnetic resonance imaging (MRI) can provide anatomical and hemodynamic information for TVE. The therapeutic target must be precisely embolized in the emissary vein, which requires guidance via multimodal MRI. Here, we report a rare case of successful TVE for a basicranial emissary vein DAVF, utilizing multimodal MRI assistance. The fistula had vanished, pterygoid plexus drainage had improved, and the inferior petrosal sinus had recanalized, as observed on 8-month follow-up angiography. Symptoms and signs of double vision, caused by abduction deficiency, disappeared. Detailed anatomic and hemodynamic assessment by multimodal MRI is the key to guiding successful diagnosis and treatment.