An ultrasound scan is a painless test that uses sound waves to create images of organs and structures inside your body. It is a very commonly used test. As it uses sound waves and not radiation, it is thought to be harmless. Doppler and duplex scans are used to visualize blood or fluids flowing through the body. Dr. Carlo Oller Board Certified Emergency Physician Please visit my website, www.DrER.tv make sure you subscribe, comment, and share! That is the best way to show your support.