Objective: This study was undertaken to investigate to what extent continuous infusion of a galactose-based microbubble contrast agent (Levovist) allows evaluation of the portal vascular system in patients with portal hypertension and for whom baseline unenhanced color Doppler sonography was nondiagnostic.
Subjects and methods: We performed color Doppler sonography at baseline and during IV Levovist infusion (4 g, 300 mg/min). First, we measured the duration of portal vein visualization during Levovist infusion in 15 patients in whom unenhanced color Doppler sonography failed to show the portal confluence from a subcostal view. This duration of improved portal conspicuity was termed "diagnostic window." We then compared in 30 patients enhanced color Doppler sonographic findings with conventional imaging methods, including portography (n = 14), helical CT (n = 4), or gadolinium-enhanced MR angiography (n = 12), and we recorded the investigator's confidence in the color Doppler sonographic result before and after Levovist infusion.
Results: The diagnostic window achieved by the Levovist infusion was 13.6 +/- 0.9 min. At baseline, color Doppler sonography was nondiagnostic in 19 patients. The diagnostic confidence level was low in all the remaining 11 patients. During Levovist infusion, color Doppler sonography remained nondiagnostic only in two of 30 patients. The confidence level was low in five patients and high in 23 patients. In 26 of these 28 patients, echo-enhanced color Doppler sonographic findings were confirmed by reference methods.
Conclusion: The continuous infusion of Levovist achieved a sufficient echo enhancement from the portal vascular bed and allowed a valid diagnostic color Doppler sonographic examination in portal hypertensive patients for whom color Doppler sonography would otherwise be nondiagnostic.