Endoscopic Ultrasound (EUS) combines ultrasound and endoscopy to obtain information about and images of the digestive tract and the tissue and organs that surround it. Ultrasound uses high-frequency sound waves to produce images of the organs and structures inside the body while endoscopy refers to the procedure of inserting a long flexible tube, or endoscope, via the mouth or the rectum to visualize the digestive tract.
Images obtained by traditional ultrasound are not always of high quality since the instruments used are outside the body. In EUS a small ultrasound transducer is installed on the tip of the endoscope allowing the transducer to get close to the organs inside the body. Your gastroenterolgist can obtain high quality ultrasound images of the organs inside the body by inserting the endoscope into the upper or the lower digestive tract.
Because of the proximity of the EUS transducer to the organs of interest, the images your doctor sees are often more detailed and more accurate than the those obtained by traditional ultrasound. The Endoscopic Ultrasound also can obtain information about the layers of the intestinal wall, lymph nodes and the blood vessels.