Ultrasound (US) uses high frequency sound waves to create pictures.  It is particularly good in looking at the organs in the abdomen and pelvis (liver, gall bladder, pancreas, kidneys, spleen, bladder, uterus, ovaries and testicles). 

It is also used to evaluate fetal development, certain breast conditions and the thyroid gland.

Color Doppler is used to examine the carotid arteries in the neck to look for narrowing.