[Echo-endoscopy: the clinical implications after a period of more than 16 years of its existence].

: Endosonography is an imaging diagnostic technique recently introduced in our country. It allows us to perform an ultrasound from within the digestive tube. Because of the transducer proximity to the gut wall and the high frequency of emission we are able to visualize with great resolution small lesions as well as differentiate the five layers of the gastric wall and examine structures close to the digestive lumen with a 7 to 8 cm penetration. This is a brief introduction to the basic pillars of endosonography and its main indications, well defined after sixteen years of clinical practice.