Most often, ultrasounds are outpatient procedures, but these tests are also used in hospitals as part of diagnostic patient care. In general, most ultrasounds follow a similar routine:

1. Depending on the area being tested, the patient may lie on a padded examining table during the test, which normally takes only about 20 to 30 minutes. It may be necessary to change into a hospital gown, depending on the area to be examined.
   
   
2. A small amount of water-soluble gel, which acts as a conducer, is placed on the part of the body to be tested and/or directly on the transducer, a small device that sends ultrasound waves through the body. The gel does not harm the skin or stain clothing. The ultrasound transducer should not be placed over an open or draining wound.
   
   
3. The technician places the transducer on the part of the body to be scanned. In some tests, a probe transducer may be placed within an opening, such as the vagina or rectum.
   
   
4. The sound waves sent from the transducer bounce off the structures within the body and the information is deciphered by the computer to create the ultrasound images.
   
   
5. The ultrasound images then appear on the television monitor and the moving pictures can be recorded on videotape.

There is no pain associated with the ultrasound test. Minor discomfort may be caused by the pressure of the transducer against the skin or, in the case of transrectal or transvaginal ultrasound, probe in a body cavity.

After the test, the gel is wiped off. The test is then evaluated by a radiologist, and results are relayed to the patient’s primary healthcare provider. If the ultrasound shows a problem, additional diagnostic tests, such as an MRI (magnetic resonance imaging), may be recommended.