COLOR DOPPLER IMAGING OF BASAL CEREBRAL-ARTERIES - NORMAL REFERENCE VALUES AND CLINICAL-APPLICATIONS

Transcranial color-coded duplex ultrasonography is a new diagnostic pr ocedure allowing the visualization of major intracranial vessels. The purpose of this report is to describe this method and to evaluate its practical potential in the routine examination of basal cerebral arter ies. The results from the examination of 96 patients are presented. By means of color coding of Doppler frequencies, the major intracranial vessels were identified by nature of their anatomic location with resp ect to the echogenic brainstem structures in all subjects. The average maximal systolic velocity was, in the middle cerebral artery, 108 +/- 15 cm/s; in the anterior cerebral artery, 96 +/- 15; in the posterior cerebral artery, 76 +/- 16; and in the basilar artery, 59 +/- 17 cm/s . The determination of the angle between the ultrasonic beam and the e xamined vessel improved the accuracy of flow velocity measurements in comparison with conventional transcranial Doppler ultrasonography. The exact measurement of blood flow velocity in several segments of the v isualized vessel proved helpful in the assessment of pathologic findin gs, especially in differentiation between a stenosis of the intracrani al vessel and a vasospasm.