[Sonographic depiction of woodchuck hepatomas using intravenously injected contrast agents]

Intravenously injected ultrasonic contrast agents have improved sonographic visualization of blood flow. On enhanced color Doppler sonography using Levovist (Schering AG, Germany) and FS069 (Molecular Biosystems, USA), minute tumor blood flow in woodchuck hepatoma was clearly demonstrated as vascular flow around and within the tumors. Furthermore, on enhanced gray scale sonography using FS069, parenchymal flow was demonstrated as sonographic "tumor stain". However, larger doses of the agent provided shadowing that disturbed sonographic evaluation of deeper portions of the liver. With advances of second harmonic imaging, it may be possible to evaluate only blood perfusion in that it eliminates the signals of fundamental frequency.