Choice of endosonographic equipment and normal endosonographic anatomy

Endosonography may be considered as a very special area in endoscopy. It really revolutionised endoscopy in allowing seeing behind the digestive lumen, in accessing the mediastinum and the pancreas, and in performing the first "NOTES" procedures. Endoscopists have usually mixed feelings towards endosonography: most of them consider EUS as the "Holy Grail" since it is one of the most complex diagnostic and therapeutic endoscopic procedures, but many users are still uncomfortable with some anatomical landmarks and with the choice of equipment. Echoendoscopes are indeed known to be costly and fragile, and quite versatile with the choice between different manufacturers, and between radial or linear (convex array) oriented instruments. This review aims at providing up-to-date information on the different types of echoendoscopes and processors and on normal endosonographic anatomy of the digestive tract, the mediastinum, the pancreas and the biliary tree.