An ultrasound machine takes internal images of deeper soft tissues by placing its probe on the skin surface. Ultrasonic sound waves traverse through the skin and underlying tissue image is formed on the monitor of machine which can be produced in the form of a picture for reporting. Any collection of fluid or tumour in the organs or cavities of the body can be detected by a radiologist with this technique. Biopsy of deeper tissues can also be taken under ultrasonic guidance. It has very important diagnostic role in investigations of cancer.