['We investigated whether color-coded Doppler sonography combined with an ultrasound contrast medium would improve the assessment of liver-supplying vessels after orthotopic liver transplantation.', 'Forty-seven patients after orthotopic liver transplantation participated. Examinations were done without and then with the ultrasound contrast medium Levovist. Visualization of the liver-supplying vessels was assessed with a scoring system.', 'Visualization of the portal vein was similar without and with contrast medium. Hepatic arteries were visualized in 39 patients without contrast medium and 46 patients with contrast medium. The remaining patient showed hepatic artery thrombosis, which was confirmed angiographically. With the use of Levovist, the examination took 3.7 min rather than the usual 6.4 min.'] Does contrast-enhanced ultrasound improve hepatic vessel visualization after orthotopic liver transplantation?