Endoscopic ultrasound elastography in digestive tract diseases

Imaging examination, such as ultrasonography, computed tomography and magnetic resonance tomography, enables one to detect pathological changes inaccessible by means of palpation. However, applying the aforementioned techniques, it is impossible to evaluate mechanical properties of examined tissues, i.e. its hardness and stiffness. Ultrasound elastography is based on the principle that the properties of a pathologically changed tissue differ from those of a normal tissue and that these tissues deform differently under the influence of ultrasonic waves. The miniaturization of equipment and the development of ultrasonographic and endoscopic techniques enabled these two methods to be combined in clinical practice. Additional information may be provided by means of elastography, conducted in the process of endoscopic ultrasound examination. In this paper we review the literature data on investigations that use endoscopic ultrasound elastography in the diagnosis of digestive tract diseases. There are notifications concerning the examination of the pancreas and lymph nodes, situated in the vicinity of the digestive tract (mainly in the mediastinum), as well as the changes in the area of the anal sphincter. Elastography examination conducted conventionally through the abdominal wall is also used in the diagnosis of liver fibrosis.