Endoscopic Ultrasonography

What is Endoscopic Ultrasound?

Endoscopic Ultrasound (EUS) combines endoscopy and ultrasound in order to obtain images and information about the digestive tract and the surrounding tissue and organs. Endoscopy refers to the procedure of inserting a long flexible tube via the mouth or the rectum to visualize the digestive tract (for further information, please visit the Colonoscopy and Flexible Sigmoidoscopy articles), whereas ultrasound uses high-frequency sound waves to produce images of the organs and structures inside the body such as esophagus, mediastinum, stomach, liver, gallbladder, pancreas, spleen aorta, rectum etc.

Traditional ultrasound sends sound waves to the organ(s) and back with a transducer placed on the skin overlying the organ(s) of interest, images obtained by traditional ultrasound are not always of high quality. In EUS a small ultrasound transducer is installed on the tip of the endoscope. By inserting the endoscope into the upper or the lower digestive tract one can obtain high quality ultrasound images of the organs inside the body. Tissue samples can also be obtained from these organs by fine needle aspiration technique. Similar technique can be used to deliver medications into or aspirate fluid from cysts.

What is the preparation for EUS?

We will want to know about your health status especially if you have any allergies, other significant health problems such as heart disease, lung disease, diabetes mellitus, or bleeding disorders etc. You will need to have an empty stomach that means no oral intake for 6 or more hours. In case of a rectal EUS you will probably need to take some enemas or laxatives. In either case, full instructions will be given to you.