Ultrasound studies are performed with a very high frequency sound beam and do not use X-ray.  They are very safe and are the main form of creating images of babies in pregnant mothers.

Ultrasound is not only safe but easy to perform and has become a major diagnostic tool in medicine.  However it has limitations.  It can't "see" through   lung or bone and is limited to evaluating certain body organs.

These include:  pregnancy, the female pelvis, liver, gall bladder, aorta, kidneys, thyroid gland and carotid artery to name a few.

Ultrasound is available at: