RRA: Ultrasound

Interventional Radiology

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Ultrasound

—How it Works
—What to Expect

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Ultrasound

Ultrasound medical imaging uses high frequency sound waves to produce images of the soft tissues and organs within the body. Like X-rays, magnetic resonance imaging and computed tomography, ultrasound is a very powerful diagnostic tool.

Ultrasound is used in obstetrics and gynecology to view the fetus or detect pelvic problems and abnormalities in the uterus or ovaries. Ultrasound is often used as a diagnostic tool to detect gallbladder, liver, and other organ abnormalities and in urology to measure blood flow through the kidney or to locate kidney stones. Its vascular applications include the evaluation of neck arteries, leg veins. In cardiology, ultrasound is used to measure blood flow and find abnormalities.

How Ultrasound works

Using the concept of echolocation, ultrasound captures the echo of a sound wave as it is reflected back from a boundary and converts that data into an image. The ultrasound machine produces electric pulses that are converted into high-frequency sound waves. These sound waves are transmitted by a hand-held probe placed against your body at the location being scanned. Although they are "sound" waves, you can’t hear them because they are beyond the frequency range of human hearing.

The sound waves travel into the body and bounce off of tissue boundaries such as bone or fluid at differing rates. That is, when a tissue boundary is hit by the sound waves, not all of the sound waves bounce back. Some continue on until they hit the next tissue boundary. When the waves are reflected back, the probe transmits them as electronic pulses back to the ultrasound machine where the distances are calculated by comparing the speed of sound in tissue and the amount of time it took each reflected wave (echo) to return. A two-dimensional image is formed on the computer screen based on the time it takes the electrical pulse to make the round trip into the body and back and by its intensity. The computer determines where on the screen to place a dot and what shade of gray that dot should be. All of those dots form an image based on the differences in the tissues being scanned.

What to expect when you have an Ultrasound
Having an ultrasound is a painless procedure that is done while you lie on a table in a slightly darkened room so the technician can better see the computer monitor. Depending on the area to be scanned, you may need to put on a gown, or loosen your clothing to allow the technician to access the appropriate area.

The technician rubs a pre-warmed gel substance on the area to be scanned to help conduct the sound waves and slowly moves a smooth probe over the area while scanning. The images appear on the computer screen in real time so the technician can see the scanned area right away. The images are recorded for later use.

There is no pain and there are no preparation procedures for ultrasound scans. When the scan is complete you may talk with an RRA radiologist about the results of the scan.

Roswell Radiology Associates
North Fulton Regional Hospital 3000 Hospital Boulevard Roswell, GA 30076 (770) 751-2530	Northwoods Medical Plaza 1230 Bald Ridge Marina Road Cumming, GA 30041 (770) 781-6350	Roswell Imaging Center 2500 Hospital Boulevard Suite 225 Roswell, GA 30076 (770) 751-2900

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