An ultrasound is an easy, painless exam, but it can get a bit messy due to the gel that is rubbed on the skin. Sound waves don’t travel through air very well. And while you might think there is no air when the probe is on the skin, the tiny hairs and dry skin hold many little pockets of air. The gel serves as a connector, eliminating the air and forming a bond between the ultrasound probe and the skin. It also reduces or eliminates static
Besides ultrasounds themselves, the gel is also used with a fetal Doppler, which can be employed to allow parents and doctors to listen to the heart beat of an unborn child.
Ultrasonic gel is usually composed of propylene glycol, water and occasionally a dye. The dye is more for looks than making it work better. It is usually clear and thick, and a little bit sticky. That way, when it is applied to the skin it doesn’t drip or run off. At the end of the procedure it can be wiped off easily.
Uses of ultrasound gel on a patient.
The size and shape of an ultrasound conductor may change, but they all use gel.