Elastography in the diagnosis of fibrosis in chronic diffuse liver diseases

The presents modern information about a non-invasive instrumental technique for assessing fibrotic changes in the liver – elastography. The data on the history of the origin of the term «elastography» are presented, several of its definitions are given, and attention is also paid to the main principle of the technique – percussion, which is traditionally used in an objective study of a patient. The facts about the dual terminology of the technique in the literature are presented, in which some authors use the term «elastography», and the other part – «elastometry». When analyzing the literature, it turned out that in foreign sources the term «elastography» is much more often used, and both names of the method are used in Russian. Given the greater prevalence of the «elastography» option, it is more logical to use it, but each of these names has its own right to exist. Definitions are given for the basic physical concepts associated with the elastography method – «elasticity», «rigidity» and Young’s modulus of elasticity. From the point of view of application in clinical practice, elastography techniques can be divided into four groups: compression elastography, which is more often used in oncodiagnostics, transient, point and two-dimensional shear wave elastography, used in the diagnosis of liver fibrosis. Physical classification involves dividing elastography into two types: static, which includes compression elastography, and dynamic, which includes transient, point and two-dimensional shear wave elastography. Transient elastography is implemented in devices of the FibroScan family, point elastography – in ultrasound scanners from «Hitachi Aloka», «Siemens» and «Philips», two-dimensional shear wave elastography – in devices from «Supersonic Imagine», «Toshiba», «Siemens», «Mindray», «General Electric». The widest range of possibilities for assessing liver fibrosis is provided by two-dimensional shear wave elastography. The combined use of several techniques is expected to increase the diagnostic accuracy in determining fibrosis. Magnetic resonance elastography has the greatest accuracy among elastographic techniques, but its application is limited due to the complexity and high cost of equipment, therefore, this technique has not yet found wide application in clinical practice.