What Is Ultrasound?

What Is Ultrasound?

Today we will focus on another imaging technique that has revolutionized the practice of medicine in the past 3 decades. Ultrasound is a noninvasive form of imaging which uses sound waves to create images of the body. That’s right – sound waves!


An ultrasound technologist, also known as a sonographer, uses a transducer (probe) on the surface of the skin, connected to a computer. The transducer transmits sound waves into the body and then receives the sound waves as they come back to the transducer after they travel through and are reflected in the body. DIfferent tissues reflect and transmit the sound waves differently, allowing images to be created. A warm gel is applied to avoid air between the probe and the skin which can interfere with transmitting the sound waves.


How does it differ from other imaging techniques?

  • Firstly, ultrasound uses no ionizing radiation. It is a safe technique when performed properly with little risks to the patient, making it ideal for use in the young or pregnant patient.

  • Ultrasound can be used real-time, meaning images can be obtained while the patient is moving. This is particularly useful when studying things like joints or in directly assessing the exact site of symptoms.

  • The patient can be examined in different positions – for evaluating some structures, like leg veins, it may be helpful to examine the patient when they are upright. Joints may also require changes in patient position.

  • The machines are small – and getting smaller. For patients in the hospital, this means that the machine can be brought to the patient, rather than requiring the patient to move.

  • Doppler is an ultrasound technique which allows the study of blood flow, helpful in assessing many parts of the body, from the arteries in the neck to blood flow in the kidneys.


If you hear ultrasound and conjure images of pregnant women getting ultrasounds, you are not alone. Many are unaware of the number of applications of the technique in the body. With ultrasound, we can image most any part of the body – from the head to your toes and all parts between.





Image credit: Philips – Ultrasound EPIQ – Abdominal by Philips Communications via Flickr Copyright Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0)

Originally published 2/25/14 on diagnosticimagingcenterskc.com.