Endoscopic ultrasound.

Endoscopic ultrasound is currently an accepted part of the clinical practice of gastroenterology. It is used to evaluate submucosal lesions, thickened gastric folds, and depth of gastrointestinal tumor penetration. As the capabilities of the instruments improve, their role in the practice of gastroenterology widens. This review is designed to update the practicing physicians on this rapidly evolving field, pertaining to instrumentation for endosonography, clinical indications for endosonography, and future directions.