Ultrasound is a high-frequency sound that you cannot hear but it can be emitted and detected by special machines.

You can’t hear these sound waves, but when they bounce off different parts of the body, they create “echoes” that are picked up by the probe and turned into a moving image.

Ultrasound may be used for treating certain conditions, particularly those of muscles, tendons and joints. The scan may be used to guide an injection which can help to treat the problem. Doing the injection with the help of an ultrasound scan makes sure it reaches exactly the right place. For example, ultrasound-guided injections are a common way to treat shoulder problems such as a frozen shoulder.