Color Doppler imaging. A new noninvasive technique to diagnose and monitor carotid cavernous sinus fistulas. Color Doppler imaging is a recent development in ultrasonography that allows for simultaneous two-dimensional structural imaging and Doppler evaluation of blood flow. With this technique, one patient with a traumatic carotid cavernous sinus fistula and two patients with spontaneous dural cavernous arteriovenous malformations were evaluated. Color Doppler imaging demonstrated a dilated superior ophthalmic vein with arterialized blood flow in all three patients. In two cases the diagnosis was confirmed by angiography, and in one of these cases the fistula was occluded with a detachable balloon catheter. Postembolization color Doppler imaging revealed return of normal venous flow in the superior ophthalmic vein. This technique offers a noninvasive means to confirm the clinical diagnosis and to track the hemodynamics of these arteriovenous fistulas. In certain cases, color Doppler imaging may eliminate the need for computed tomography and magnetic resonance imaging in the evaluation of suspected arteriovenous malformations of the orbit. 