Duplex Doppler investigation of suspected vascular lesions at the carotid bifurcation.

This prospective study was undertaken to evaluate the role of duplex Doppler (DD) scanning in the diagnosis of masses of suspected vascular origin at the carotid bifurcation. We also assessed the different DD signs of carotid body tumors, especially the difference in resistance index (RI) in the external carotid artery on the side of the tumor. Over a 3-year period (1987-1991) all patients (n = 50) with masses of suspected vascular origin at the angle of the mandible underwent DD investigation. The clinical diagnoses included carotid body tumors and carotid bifurcation area aneurysms. Arteriography was also performed in all patients. DD examination diagnosed carotid body tumors in 11 patients, aneurysms in 5, nonvascular lesions in 11, carotid artery kinks in 10, and a prominent carotid bifurcation in 13 patients. In 23 of 50 patients (46%) no pathology (kinks and prominent vessels) was present. DD imaging proved to be 100% accurate in diagnosing these lesions as determined by arteriography. The DD findings in carotid body tumors demonstrated a "wineglass" bifurcation containing a lesion with echoes as well as pronounced and turbulent multidirectional flow ("hypervascular tumor flow"). Low-resistance flow was present in the external carotid artery in 80% of patients, indicating the blood supply of the tumor. Patients with lumps of suspected vascular origin at the carotid bifurcation should be initially investigated by DD examination, which can accurately exclude the diagnosis of carotid body tumors and carotid aneurysms and clearly eliminate arteriography in these patients.