Measurement of cerebral circulation time by contrast-enhanced Doppler sonography

We present a new, non-invasive ultrasound method for the measurement of cer ebral circulation time. After injection of a galactose-based echo-contrast agent (Levovist) into an antecubital vein, cerebral circulation time is mea sured as the interval between the beginning of a stable signal enhancement of at least 5 dB in the internal carotid artery and in the ipsilateral inte rnal jugular vein. Both vessels are insonated simultaneously at the mandibu lar angle using a single 2-MHz range-gated transducer. For this study, 25 h ealthy volunteers ranging in age from 23 to 55 years (30.1 +/- 7.5 years; m ean +/- SD) were examined. Cerebral circulation time was 5.6 +/- 1.7 s with out significant side-to-side or sex-related differences. Measurement of cir culation times offers a new possibility for the employment of echo-contrast agents in functional ultrasound. Copyright (C) 2000 S. Karger AG, Basel.