All unsuccessful revolutions are the same, but each successful one is different in its own distinctive way. The reason why revolutions occur is that new forces attain increasing significance and classic institutions are incapable of accomodating these forces. Such has been the pattern of events in the English, American and French revolutions. These successful revolutions produced a new dynamic and new perspectives. One English revolutionary put this succinctly: "Let us be doing, but let us be united in doing." This book sets out what is a revolution in. the perspectives of diagnostic imaging of the kidney and urinary tract. Forces which have brought about this revolution are the advent of reliable techniques in radioisotope studies, ultrasonics and computerized tomographic (CT) scanning. This last modality carries with it specific problems for routine paediatric work and its role in the study of kidney and urinary tract problems is discrete and circumscribed. However, in conjunction with classic radiology, each of these techniques yields information of a different type and so a synthesis of data accrues.