Current status and future applications of contrast-enhanced endoscopic ultrasonography

Endoscopic ultrasonography (EUS) is currently an integral investigation of many gastrointestinal disorders. It has been shown to have a higher efficacy than conventional computed tomography in detection and characterization of small lesions especially in the pancreas. Much effort has been put to further improve the sensitivity, specificity and overall accuracy of EUS. One of the major advances is the utilization of contrast agents for better delineation of the vascularity and tissue perfusion of the target lesion. This article describes the basic principles of ultrasound contrast agents and the different modalities used in contrast-enhanced EUS (CE-EUS) including contrast-enhanced Doppler EUS (CED-EUS) and contrast-enhanced harmonic EUS (CEH-EUS). In addition, the current applications of contrast enhanced EUS in different gastrointestinal conditions were discussed. Furthermore, the future development of hybrid approaches combining CE-EUS with other imaging modalities and the potential therapeutic aspect of using it as a vector for drug delivery were also discussed.