ABSTRACT
Medical ultrasound involves the use of high frequency sound waves to create an image of the various parts of the body. The sound waves are created by passing an electrical current across a special (piezoelectric) crystal. As they travel through the area of interest, the waves are reflected by the various organs and tissue to a varying extent. The reflected waves are detected by the same crystals to generate an image. Once used purely as a diagnostic tool by the radiologist, ultrasound's role has expanded into all areas of medicine including the acute specialties such as intensive care. There is no limit to the various modalities or organs that can be imaged with ultrasound and its use continues to expand. The most common modalities in the intensive care setting are echocardiography, lung ultrasound, abdominal ultrasound, and vascular ultrasound. Echocardiography can be divided into trans-thoracic or trans-oesophageal.
