An ultrasound, also called a sonogram, uses sound waves to produce pictures of the body. Ultrasounds do not involve radiation and are usually painless. Doppler ultrasound can follow blood flow in major arteries and veins in the abdomen, arms, legs and neck. Ultrasound is also used to help doctors during some procedures.
Areas of the body are scanned in real time so the images can show the structure and movement of the body's organs, as well as blood flow in the vessels. During an ultrasound, when the sound waves reach an object, it bounces backward or echoes. By measuring the echo wave, it is possible to determine the size, shape and consistency of the object being studied.