Prior to development of better resolution duplex Doppler systems, blood flow velocities of the middle cerebral artery, anterior cerebral artery, and posterior cerebral artery were obtained in a "blind" manner, ie, the vessels were not imaged. We performed duplex transcranial Doppler examinations on 13 healthy volunteers and obtained peak velocities as well as resistive indices on all three arteries. The vessels were identified by their anatomic locations with respect to the brainstem and by the echogenic pulsating structures. This duplex transcranial Doppler examination holds promise for improving reproducibility and for detecting pathologic vascular states.