An ultrasound test allows your physician to see blockages or narrowing in your blood vessels and determine the size of your kidneys. When performed in the heart, ultrasound is called echocardiography. Duplex ultrasound can generate images of the walls of a blood vessel as well as measure the rate at which blood is flowing through a vessel.

How Does It Work?

Ultrasound uses sound waves that are emitted at a higher frequency than humans can hear. A hand-held wand called a transducer is pressed against the skin. This transducer sends out the sound waves, which bounce off the structures inside the body. These sound waves are then picked up by the transducer as they bounce back. A computer converts the sound waves into two-dimensional moving pictures.

How Is It Performed?

You will experience little or no discomfort during an ultrasound test. To prepare for the ultrasound test, you should avoid eating or drinking (except for important medication with sips of water) from midnight of the night prior to your test. You should ask your doctor about continuing to take your medications before the examination.

Before the test, the technologist will ask you to lie flat on a table. A gel is applied to the skin over the arteries that will be examined. The gel improves transmission and reception of the ultrasound waves. The technician then presses the transducer against the skin over the area of your body being examined and slides it back and forth. The pressure may cause minimal discomfort. As the wand moves, it sends information to a computer that produces images that can be recorded and viewed on a screen.

Is It Safe?

There are no known risks associated with a standard ultrasound test.

Duplex Ultrasound

Duplex ultrasound allows a physician to gather information not just about structures in the body, but also how blood moves through blood vessels by combining regular ultrasound with Doppler ultrasound. Doppler ultrasound is capable of analyzing sound waves that are emitted and then bounce back from moving red blood cells. This information is interpreted by a computer to show the speed at which blood cells are moving through a blood vessel.

Questions to Ask Your Doctor About Ultrasound and Duplex Ultrasound

The following questions can help you talk to your physician about an ultrasound test and duplex ultrasound. Print out or write down these questions and take them with you to your appointment. Taking notes can help you remember your physician’s response when you get home.

Ultrasound

• What symptoms or test results indicated that an ultrasound test might be beneficial?
• What will the ultrasound test tell us about the health of my blood vessels or kidneys?
• What happens next if the ultrasound test identifies a possible problem?

Duplex ultrasound

• What symptoms or test results indicated that it might be beneficial to assess the speed at which blood cells are moving through my blood vessel?
• What will the duplex ultrasound test tell us about the health of my blood vessels?
• What happens next if the duplex ultrasound test identifies a possible problem?

Please print this list of questions here. Take them with you to the doctor and share them with friends and loved ones when you are encouraging them to see their doctors.