ultrasonography

The use of high-frequency sound waves to image internal body structures, a developing fetus, or objects and currents that are underwater.

The use of ultrasound to produce diagnostic images of the internal organs of the body, or of a foetus.

The use of ultrasound to form images of underwater structures.

using the reflections of high-frequency sound waves to construct an image of a body organ (a sonogram); commonly used to observe fetal growth or study bodily organs