Role of contrast enhanced ultrasound in the assessment of biliary duct disease.

The introduction of microbubble contrast agents (CA), which act as blood pool tracers, has overcome the limitations of conventional B-Mode, colour or power Doppler ultrasound, enabling the display of parenchymal microvasculature. Initially, the use of CA was accepted for hepatic lesions. In the following years, experts have expanded recommendations, as a result of the method's efficiency in extrahepatic applications. In this article we review the methodology and the application of contrast-enhanced ultrasound (CEUS) in the evaluation of biliary pathology. This new imaging tool allows a non invasive differential diagnosis of biliary lesions and a clearer delineation of the tumoral process.