In less than 100 seconds, Mathias Fink introduces this medical technique used to generate images of the inside of the body. To produce ultrasound images, medical physicists target sections of the body with ultrasound and then study the reflected signal to build images of internal structures. In essence, they are doing the same thing that dolphins do when they are searching for fish.

Medical ultrasound is most commonly associated with the field of obstetrics, where it is used to generate images of the foetus developing in the womb. It is also used for studying the heart and abdominal regions. Fink, a researcher at Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI) in France, explains how some modern versions of ultrasound can produce around 10,000 images per second. This enables medical scientists to track mechanical waves through the body to create maps of the elasticity of tissue. This can be particularly useful in the diagnosis of cancer, where tissue stiffness can reveal details about the nature of the disease.

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