Question: How can you use an ultrasound machine to look at cancer

Leo Garcia answered on 21 Jun 2010:

Ultrasound scanners send sound waves into the body, and detect the echoes which bounce back. Some tumours can be detected with an ultrasound scan, because they have different sound scattering properties than healthy tissue – and show up as shapes which should not be present in a healthy patient. For an example, look here:

http://www.imaginis.com/breast-health/ultrasound-images-of-breast-conditions-1
http://www.imaginis.com/breast-health/ultrasound-images-of-breast-conditions

Notice that malignant breast tumours appear darker on the scan than healthy tissue, and often have a star-like irregular shape. Not all cancers are detected by ultrasound, though – which is why the field I work in, called ultrasound elastography, was invented. It images stiffness, instead of sound scattering properties, which can often provide much more contrast between cancer and healthy tissue than on ultrasound alone. Have a look at some pictures here:

http://www.uth.tmc.edu/schools/med/rad/elasto/journalarticles.htm
http://www.uth.tmc.edu/schools/med/rad/elasto/recent.htm