This atlas covers "virgin territory in the field of sonography". tumours, all of these have allowed us to derive general statements as Cultivation of this territory has been made possible a) by the develop­ to signal enhancement in different types of liver lesion. ment of a signal enhancement agent consisting of gas microbubbles which are able to pass through the lungs and are capable of re­ Here, similarities were found with other imaging procedures which sonance and b) by the technical realisation of 2nd harmonic imaging. also make use of contrast agents. Both of these have been available to us since April 1996. Haemangiomas receive special attention in this book. This is due This book stems from the particular situation of a long friendship to their frequent occurrence and the outstanding improvements in dia­ between a physicist with medical knowledge and a physician with gnosis which are provided by echo enhancers. technical expertise. The equipment settings and the examination pro­ cedure which form the basis for the images in the atlas are the result We are convinced that an echo-enhanced sonography that pro­ of intensive efforts, originating in a desire to achieve the maximum vides few artefacts will have an important role to play in the future. that is physically feasible and clinically desirable. This procedure is Our results to date justify the assumption that additional diagnostic now routine in our Sonography Department. procedures can be dispensed with when echo-enhanced ultrasound findings are clear.