[Clinical application of endoscopic ultrasonography (EUS) for gastrointestinal diseases]

Endoscopic mucosal resection (EMR) has been widely employed as a minimally invasive surgical procedure for early digestive cancers. Moreover, many recent reports emphasize the usefulness of endoscopic ultrasonography (EUS) for diagnosis of early gastrointestinal cancers. Generally, the normal gastrointestinal wall is visualized as having five layers by endosonographic probes of 7.5, 12, or 20 MHz. Delineation of these layers is the most important point for feature of EUS. Only mucosal cancers that are disclosed as hypoechoic masses within the first to second layer are indicated for EMR. The development of further extracorporeal applications such as color Doppler, 3-D, and aspiration biopsy EUS will contribute to the increased use of EUS in the near future.