Color Doppler imaging allows simultaneous bidimensional imaging and Doppler evaluation of blood flow in orbital vessels. We report 4 cases in which color Doppler imaging was used to diagnose and monitor carotid cavernous fistulas. In all cases, color Doppler imaging demonstrated dilated, arterialized superior ophthalmic veins; these findings were confirmed by angiography. Two patients underwent embolization with complete regression of the clinical findings. After embolization, color Doppler imaging revealed normal, laminar flow in the superior ophthalmic vein. This noninvasive technique represents a safe and fast method that is useful in the diagnosis and post-treatment follow-up of carotid cavernous fistulas. (C) 1997 John Wiley & Sons, Inc.258448452