Liver and Spleen

Abstract

The liver and spleen are difficult to image with ultrasound because the overlying ribs, by preventing the transmission of ultrasound, obscure portions of these organs. In addition, since regions of the liver and spleen are larger than the field of view of a realtime scanner, a cross section of either of these organs often cannot be included on a single image. However, real-time imaging of the liver has several advantages over contact scanning. Small intrahepatic lesions can be more readily identified by real-time imaging than by contact scanning because the entire volume of the liver is continuously imaged as the real-time transducer sweeps through it, whereas with contact scanning serial scans are obtained with discrete spaces between the scans. In addition, when a questionable mass is identified, it can be more readily characterized as cystic or solid by real-time than by contact scanning since the beam can be more easily manipulated perpendicular to the surface of the mass and swept through the mass from side to side so as to both define its margins and internal echo pattern.