B-scan ultrasonic evaluation of a dilated superior ophthalmic vein in orbital and retro-orbital arteriovenous anomalies.

All patients between 1977 and 1982 who presented with unilateral exophthalmos were evaluated with contact B-scan ultrasonography. Of these, eight patients were diagnosed as having retro-orbital or orbital arteriovenous anomalies (two carotidcavernous sinus fistulas, four dural arteriovenous malformations, and two orbital arteriovenous malformations). On B-scan ultrasound, all of these patients demonstrated a dilated superior ophthalmic vein. None of the other patients with unilateral proptosis demonstrated this finding. With recent advances in treatment of these conditions, early diagnosis becomes increasingly important. Contact B-scan ultrasonography (which is widely available, convenient, and expedient) can be used for early diagnosis of arteriovenous anomalies in the orbit and cavernous sinus areas. Other ultrasonic techniques such as A-scan, standardized A-scan, or immersion B-scan, are equally reliable in the recognition of a dilated superior orbital vein. In the authors' opinion, however, these are less convenient, more time consuming, and require more expertise for similar results.