The EUS medical abbreviation stands for endoscopic ultrasound, a procedure that combines a flexible camera scope with a small ultrasound probe at its tip. Because the probe sits right against the wall of the stomach or bowel, it can take close, detailed images of the pancreas, bile ducts, liver edge, lymph nodes and the layers of the gut wall.
EUS is done by gastroenterologists with extra training, usually under sedation. It often includes a fine needle sample of a lump or cyst. This page explains how it works, how it differs from related scope tests, and how a report line reads.
At a glance
Stands for
Endoscopic ultrasound (also called endosonography)Used in
Gastroenterology, oncology, surgeryLooks at
Pancreas, bile ducts, gut wall layers, nearby lymph nodesSampling
FNA (fine needle aspiration) or FNB (fine needle biopsy)Do not confuse with
EGD (camera only) and ERCP (treats ducts with X-ray)Preparation
Fasting beforehand; a bowel prep for lower EUS
How endoscopic ultrasound works
An ordinary ultrasound sends sound waves through the skin, and gas or fat can blur the view of deep organs. EUS solves this by placing the probe inside. For an upper EUS, the scope passes through the mouth into the esophagus, stomach and first part of the small intestine. From there, the pancreas and bile ducts are only a short distance away. A lower EUS passes through the rectum to look at the rectal wall and nearby tissue.
The doctor sees both the camera view and the ultrasound picture on screens during the test.
Common reasons for the EUS medical abbreviation in a plan
- Studying a mass or cyst in the pancreas.
- Looking for stones in the common bile duct.
- Staging cancers of the esophagus, stomach, pancreas or rectum by showing how deep they go.
- Sampling lymph nodes or lumps under the gut lining.
- Guiding some treatments, such as draining a fluid collection or nerve block for pain.
EUS compared with other scope procedures
| Shorthand | What it does |
|---|---|
| EGD | Camera look at the esophagus, stomach and duodenum lining |
| EUS | Camera plus ultrasound to see through the wall and beyond |
| ERCP | Scope with X-ray dye to image and treat bile and pancreatic ducts |
| MRCP | Magnet scan of the ducts with no scope at all |
EUS and ERCP are sometimes done in the same session: EUS finds the problem, and ERCP removes a stone or places a stent.
A report line, explained
Procedure note: "EUS: 2.1 cm hypoechoic pancreatic head mass abutting the SMV. FNB x3 passes, specimens to pathology." The ultrasound found a darker area, about two centimeters, in the head of the pancreas, touching a nearby vein. Three needle samples were taken for the lab to examine.
Hypoechoic means the area sends back fewer sound echoes than the tissue around it. Pathology results usually arrive days after the procedure and help settle the diagnosis.
Preparing for and recovering from EUS
For an upper EUS, people are usually asked to be NPO, taking nothing by mouth for several hours. A lower EUS may need an enema or bowel prep. Blood thinners and diabetes medicines may need a plan made in advance with the prescriber. Because sedation is given, someone else drives you home.
Afterward, a scratchy throat and some bloating are usual and tend to fade quickly. More GI and imaging shorthand is gathered on the lab and scan abbreviations page.
Questions to ask before the procedure
- Will samples be taken, and when will results be ready?
- What should I do about my usual medicines?
- Could another procedure, such as ERCP, happen during the same visit?
- Which symptoms afterward should prompt a call?
Every EUS is planned around a specific question. Your gastroenterologist can explain why it was recommended for you and what the findings mean.
Frequently asked questions
What does EUS stand for?
EUS stands for endoscopic ultrasound, a thin, bendable camera tube fitted with a sound wave probe. It images organs next to the gut from the inside.
Is EUS the same as an endoscopy?
It is a type of endoscopy, but with an ultrasound probe added. A standard upper endoscopy only shows the inner lining, while EUS shows the deeper layers and nearby organs.
Are you asleep for an EUS?
Most people receive sedation and remember little or nothing of the procedure. The type of sedation depends on the center and on your health.
How long does an EUS take?
Many take under an hour, though time varies with whether samples are taken or treatment is done. Recovery from sedation adds time before you go home.