Ultrasonic energy was first used for medical purposes (for neurological problems) in the late 1940s. The first compound contact B-mode scanner (the patient sat in a water-filled barrel with the sensor circulating around) was developed 20 years later and the first commercial hand-held transducer was released around 1965. Since then, concurrently in various countries, sonography became used more and more frequently by a range of medical disciplines. Around 1960 the Doppler effect principle was applied for the first time for cardiovascular diagnostics. Colour-coded duplex sonographic devices were launched only after 1980, when computer technology was applied to enhance sonographic pictures. Since then the image information on ultrasound machines has improved rapidly. {25, 26}