Supraorbital approach of the anterior cerebral artery: a new window for transcranial doppler sonography

　　Usually, a transtemporal Doppler sonographic study of the anterior cerebral artery can insonate the Al segment only. We found a new window just above the supraorbital ridge to approach the A2 segment and even the proximal portion of the pericallosal segment in 17 of 21 volunteers aged from 16 months to 39 years. The failed four cases had an average age of 23 years. We suggest that the supraorbital approach can be tried as another window during　transtemporal approach has failed.