Ultrasound is a safe, radiation-free imaging procedure that utilizes echoes of sound waves to visualize soft tissue and fluids in the body. It is particularly good in examining 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.