[Use of the ultrasound contrast medium levovist in after-care of liver transplant patients. Improved vascular imaging in color Doppler ultrasound].

INTRODUCTION

A study was carried out to determine whether an improvement in the detection of vascular signals in patients after orthotopic liver transplantation can be achieved by the use of ultrasound contrast medium in colour Doppler sonography.

MATERIAL AND METHODS

In the early postoperative follow-up of liver transplant recipients, 31 colour Doppler sonograms were obtained in 21 patients before and after intravenous injection of the ultrasound contrast agent Levovist (Schering, Berlin). A grading score with four categories was used to evaluate the sonograms with special regard to the visibility of colour and flow signals in the hepatic artery and also in the portal vein and the hepatic veins. The arterial and portal venous signals were evaluated in the hepatic portal and in the left and right lobe.

RESULTS

With contrast enhancement significantly better arterial signals were seen in 20 of 31 sonograms for the hepatic portal, in 22 for the right lobe and in 26 for the left lobe. Better portal vein signals were obtained in 17 of 31 examinations for the right lobe and in 16 for the left lobe; only little improvement was obtained for the main stem of the portal vein. For the hepatic veins there was no significant improvement.

CONCLUSIONS

Early vascular complications after liver transplantation usually occur in the hepatic arteries. With the use of contrast-enhanced colour Doppler sonography, better detection of arterial and peripheral portal signals can be achieved; peripheral portal vein branches can be helpful in finding small arteries.