How do ultrasound scans work?

An ultrasound scan uses high-frequency sound waves to create images of the inside of the body. It is suitable for use during pregnancy.

Ultrasound scans are safe because they use sound waves or echoes to make an image, instead of radiation.

Ultrasound scans are used to evaluate fetal development, and they can detect problems in the liver, heart, kidney, or abdomen. They may also assist in performing certain types of biopsy.

The image produced is called a sonogram.

Fast facts on ultrasound scans

Ultrasound scans are safe and widely used.

They are often used to check the progress of a pregnancy.They are used for diagnosis or treatment.No special preparation is normally necessary before an ultrasound scan.

The person who performs an ultrasound scan is called a sonographer, but the images are interpreted by radiologists, cardiologists, or other specialists.

The sonographer usually holds a transducer, a hand-held device, like a wand, which is placed on the patient’s skin.

Ultrasound is sound that travels through soft tissue and fluids, but it bounces back, or echoes, off denser surfaces. This is how it creates an image.

The term “ultrasound” refers to sound with a frequency that humans cannot hear.

For diagnostic uses, the ultrasound is usually between 2 and 18 megahertzTrusted Source (MHz).

Higher frequencies provide better quality images but are more readily absorbed by the skin and other tissue, so they cannot penetrate as deeply as lower frequencies.

Lower frequencies penetrate deeper, but the image quality is inferior.