Endoscopic ultrasound elastography-- a new imaging technique for the visualization of tissue elasticity distribution.

Endoscopic ultrasound (EUS) elastography is an imaging procedure used for the visualization of tissue elasticity during usual EUS examinations. EUS elastography can be accomplished real-time with state-of-the-art ultrasound systems, with the images being represented in transparent color superimposed on the conventional gray-scale B-mode scans. The aim of this review was to introduce the potential range of applications of EUS elastography. EUS elastography might be useful for the differentiation of benign and malignant lymph nodes, with a qualitative pattern analysis and a quantitative histogram analysis of the color images being used to adequately classify the lesions. Mapping of the tissue elasticity distribution might be useful for the differential diagnosis of focal pancreatic masses, especially in the setting of chronic pancreatitis where the accuracy of EUS-guided fine needle aspiration is also low. EUS elastography might also enhance the detection and differentiation of various solid tumors (adrenal tumors, submucosal tumors, etc.) situated nearby the gastrointestinal tract. Routine use of EUS elastography thus offers supplemental information that enhances conventional EUS imaging, with a possible decrease in the number of un-necessary EUS-FNA procedures used for tissue confirmation. However, future enhancements of the EUS elastography technology, as well as prospective, randomized studies will probably establish the clinical impact of dynamic elasticity imaging.