Question

How does an ultrasound produce an image of a fetus in the mother’s uterus?

Answer 1

Ultrasounds bounce inaudible sound waves off the solid structures in the body to create a 2D image.

The solid structures reflect sound waves, creating a white or gray appearance.

Answer: for e2020

Answer 2

The ultra sound waves coming from the transmitter pass through the body and once they hit a boundary (the baby) they are partially reflected back to the transmitter and the image appears on the screen. The longer the time taken is to reflect, the further away it is, so darker/lighter on the picture.