Endoscopic ultrasound for non-gastroenterologists: what you need to know.

Endoscopic ultrasound (EUS) combines the use of flexible fiberoptic endoscopes with high-resolution ultrasound technology. It is increasingly used for the evaluation, staging, and diagnosis of many luminal and extraluminal gastrointestinal (GI) cancers, as well as non-GI tract ailments, including the staging of lung cancer. In the past decade, EUS has become available on a wide scale, with an increasing number of indications. The technology has been shown to be comparable with and often more sensitive than computed tomography scan and magnetic resonance imaging in staging many malignancies. The use of fine-needle aspiration and ultrasound-guided injection also allows for accurate tissue diagnosis and therapy of GI ailments. Despite increasing availability and indications for EUS over the past decade, general internists may not be aware of EUS technology, when to order an EUS, and how to integrate the results of an EUS into their management decisions. This article will review the general indications for EUS referral, limitations, and role of EUS in the practice of general medicine.