This article presents a review of the methods of determining spleen size in sonography, computed tomography, and magnetic resonance imaging. The review aims to summarize the data on the methods of estimating the linear dimensions of the spleen and splenic volume and describe the physiological variability of spleen size depending on sex, age, and different physiological conditions. We systematized the methods used for measuring the spleen and presented them in the form of a table, analyzed the results of previous studies, and compared the accuracy of different methods of calculating the splenic volume using a variety of diagnostic methods.

The article is devoted to numerical methods for solving the problem of diffraction of electromagnetic waves by conducting bodies. Two approaches to solving the problem are considered. The first one is based on the use of the thin-wire integral representation of the electromagnetic field (TP-method) for a grid model of the body surface. The second approach is associated with the use of the basis functions of RaoWiltonGlisson when solving a vector integral equation formulated with respect to the electric current density on the body surface (RWG-method). The diffraction of a plane linearly polarized electromagnetic wave by a sphere is considered as a test problem. The results of calculations of the normalized diagrams of the scattered field are presented. It is shown that there are practically no visual differences for the results obtained using both approaches. At the same time, it should be noted that the TP method is much simpler in numerical implementation than the RWG method.

The review presents data on the comparison of the features of liver and spleen stiffness measurements and those on the impact of various conditions on the measurement results (the type of a sensor used, food intake, number of measurements, patient position, breathing phase, etc.). Literature has been sought in the PubMed and eLibrary databases. In particular, the liver and spleen stiffness values vary differently at the height of inspiration and expiration. This is due to organ engorgement with a change in intrathoracic and intraabdominal pressures, as well as to a reduction in splenic arterial flow during exhalation. The review gives published data on liver and spleen stiffness values in healthy volunteers. The spleen is a stiffer organ than the liver. The different liver and spleen stiffness is explained by the features of blood supply (the spleen receives the most blood supply from the intensive-flow artery; the liver does from the portal vein). The reasons for increasing the stiffness of these organs in both health and disease are described. Estimation of liver stiffness can be used to diagnose cirrhosis and portal hypertension. That of spleen stiffness can help in the diagnosis of portal hypertension and in the indirect diagnosis of the presence of esophageal varices and the nature of a splenic lesion.