It is well-known that, in the past few decades, imaging techniques, and in particular ultrasonography, have led to great advances in clinical hepatology. In fact, the widespread use of these techniques resulted in the clinical discovery of hepatocellular carcinoma and other liver tumours. Hepatocellular carcinoma was practically unknown to the clinician before the advent of diagnostic ultrasound. Real-time ultrasonography remains the most frequently used imaging procedure for the primary diagnosis of mass liver lesions and for the survey of patients affected by chronic liver diseases and tumours of the gastrointestinal tract
