Traumatic Carotid-Cavernous Fistula

The intraorbital contents should be carefully evaluated in the setting of trauma. A carotid-cavernous fistula can be suggested on non-contrast studies by the enlargement of the superior ophthalmic vein and extraocular muscle(s). The cavernous sinus will also be enlarged, but may not be seen on non-contrast CTs. A CTA can be performed to evaluate the cavernous sinus. CTA of the brain may show dilatation and early enhancemnet. Angiography is considered the gold standard for diagnosis and can be used for treatment.

A potential pitfall is isolated dilatation of the superior ophthalmic vein, which can be seen as a normal variant, in cavernous sinus thrombosis, venous varix, and Graves disease.