For endoscopic ultrasound of the upper digestive tract, a probe is inserted into the esophagus, stomach, and duodenum during a procedure called esophagogastroduodenoscopy.

It also allows for characterization and biopsy of any focal lesions found in the upper gastrointestinal tract, such as esophageal tuberculosis.

From various positions between the esophagus and duodenum, organs within and outside the gastrointestinal tract can be imaged to see if they are abnormal, and they can be biopsied by a process called fine needle aspiration.

Organs such as the liver, pancreas, and adrenal glands are easily biopsied, as are any abnormal lymph nodes.

This occurrence may cause obstruction of the drain shared by the liver and pancreas, which may lead to lower back pain, jaundice, and pancreatitis.

An endoscopic ultrasound probe placed in the esophagus can also be used to visualize lymph nodes in the chest surrounding the airways (bronchi), which is important for the staging of lung cancer.