Spontaneous thrombosis of a direct carotid cavernous sinus fistula: confirmation by Gd-DTPA-enhanced MR.

A 38-year-old man was admitted for possible embolization of a left carotid cavernous sinus fistula. Two months previously, the patient had been admitted to the hospital after a motorcycle accident. Twenty-four hours later, he was noted to have left proptosis, chemosis, and a third-nerve palsy. An angiogram was performed and showed a carotid cavernous sinus fistula (Fig. 1 A). The patient was referred to our institution for embolization. Physical examination revealed marked left proptosis and chemosis, but no orbital bruit was present. A repeat angiogram failed to show the fistula (Fig. 1 B). Thrombosis of the left cavernous sinus was suspected, and two sets of MR images were obtained, one set before and one set after gadolinium-DTPA injection (Figs. 1 C and Fig. D).