Ultrasound

Ultrasound is a high frequency sound that you cannot hear, but it can be emitted and detected by special machines.Ultrasound travels freely through fluid and soft tissues but is reflected back (it bounces back as 'echoes') when it hits a more solid (dense) surface. For example, the ultrasound will travel freely though blood in a heart chamber, but when it hits a solid valve, a lot of the ultrasound echoes back. Another example: when ultrasound travels though bile in a gallbladder it will echo back strongly if it hits a solid gallstone. So, as ultrasound 'hits' different structures in the body of different density, it sends back echoes of varying strength.You lie on a couch and an operator places a probe on your skin over the part of your body to be examined. The probe it is a bit like a very thick blunt pen. Lubricating jelly is put on your skin so the probe makes good contact with your body. The probe is connected by a wire to the ultrasound machine and monitor. Pulses of ultrasound are sent from the probe through the skin into your body. The ultrasound waves then echo ('bounce back') from the various structures in the body.The echoes are detected by the probe and are sent down the wire to the ultrasound machine. They are displayed as a picture on the monitor. The picture is constantly updated so the scan can show movement as well as structure. For example, the valves of a heart opening and closing during a scan of the heart. The operator moves the probe around over the skin surface to get views from different angles.The scan is painless and takes about 15-45 minutes, depending on which parts of the body are being examined. A record of the results of the test can be made as still pictures or as a video recording. Ultrasound scans are painless and safe. Unlike x-rays and other imaging tests, ultrasound does not use radiation. It has not been found to cause any problems or complications.