[Color-coded duplex ultrasound of the vertebral artery: normal findings and pathologic findings in obstruction of the vertebral artery and remaining cerebral arteries]

Abstract

Aim: The aim of this study was to determine normal values of flow velocities in the extracranial vertebral artery (VA) with regard to diameter of the VA, blood pressure and age. Hemodynamic changes in the VA in occlusive disease of the brain supplying arteries were also to be investigated. Based on the findings the clinical value of CCDS for the investigation of the VA were to be assessed.

Method: The evaluation was carried out by a CCDS-scanner with a 7.5 MHz transducer in 85 normal individuals and in 166 patients with occlusive disease of the cerebral arteries.

Results: The average maximal systolic flow velocity was 59 +/- 17, time averaged maximal velocity 31 +/- 10 and enddiastolic velocity 19 +/- 8 cm/sec. Significantly reduced flow velocities were found in severely stenosed and in occluded VA increased flow velocities in VA serving as collateral pathway in higher grade obstructions of contralateral VA, ICA, and SCA.

Conclusion: CCDS of the VA is a valuable tool in diagnosis of severe obstructions of the VA, but also for demonstration of collateral flow. Furthermore, cervical collateral pathways in severe obstruction of the VA-origin can be detected. Diagnosis of moderate stenosis of the ostium of the VA remains difficult.