Interventional endoscopic ultrasonography.

Endoscopic ultrasonography (EUS) is the combination of endoscopy and intraluminal ultrasonography. This allows use of a high frequency transducer, which, due to the short distance to the target lesion, enables ultrasonographic images of high resolution to be obtained. Endoscopic ultrasonography is now a widely accepted modality for the diagnosis of pancreatobiliary diseases. It can be used to determine the depth of invasion of gastrointestinal malignancies, and often for visualizing lesions more precisely than other imaging modalities. The most important early limitation of EUS was the lack of specificity in the differentiation between benign and malignant changes. In 1992, EUS-guided fine needle aspiration (EUS-FNA) of lesions in the pancreas head has been made possible using a curved linear array echoendoscope. Since then, many researchers have expanded the indication of EUS-FNA to various kinds of lesions and also for a variety of therapeutic purposes. In this review, we particularly focus on the present and future roles of interventional EUS, including EUS-FNA and therapeutic EUS.