An Ultrasound machine uses high frequency sound waves to create pictures of a variety of body structures including the internal organs of the abdomen and pelvis and the arteries and veins. Ultrasound is not usually used to assess bones or the intestines. Unlike x-rays and CT scans, ultrasound does not use radiation and therefore may be used safely during pregnancy. A Carotid Duplex Ultrasound is a noninvasive way to look at the carotid arteries to determine if there is any plaque buildup. AAA Screening prevention uses ultrasound to check for aneurysm in the abdomen.