The role of endoscopic ultrasound in pancreatic disorders.

Abstract

Endoscopic ultrasound (EUS) represents one of the major advances in gastrointestinal endoscopy in the past 10 years. Originally designed to image mass lesions in the esophagus and stomach, the technique has been increasingly applied to a wide range of gastrointestinal disorders. Since the pancreas lies in such close proximity to the stomach and duodenum, imaging of the pancreas has become particularly successful. EUS imaging of the upper gastrointestinal tract has become possible with the development of small ultrasound probes that can be placed in the esophagus and stomach. Most commonly, EUS probes are located on the tips ofendoscopes, and imaging of the pancreas is possible from locations in the duodenum and stomach. The frequency of the ultrasound waves emitted and received by an ultrasound probe determines the depth of penetration and resolution; highfrequency waves produce high-resolution images with a shallow tissue penetration and low-frequency waves result in lower-resolution images. For optimal imaging of the pancreatic-biliary system, midrange