• Definition
    • Ultrasound uses high-frequency sound waves to make images of organs and structures inside the body.

  • Alternative Names
    • Sonogram

  • How the Test is Performed
    • An ultrasound machine makes images so that organs inside the body can be examined. The machine sends out high-frequency sound waves, which reflect off body structures. A computer receives the waves and uses them to create a picture. Unlike with an x-ray or CT scan, this test does not use ionizing radiation.

      The test is done in the ultrasound or radiology department.

      • You will lie down for the test.
      • A clear, water-based gel is applied to the skin on the area to be examined. The gel helps with the transmission of the sound waves.
      • A handheld probe called a transducer is moved over the area being examined. You may need to change position so that other areas can be examined.
  • How to Prepare for the Test
    • Your preparation will depend on the part of the body being examined.

  • How the Test Will Feel
    • Most of the time, ultrasound procedures do not cause discomfort. The conducting gel may feel a little cold and wet.

  • Why the Test is Performed
    • The reason for the test will depend on your symptoms.

  • Normal Results
    • Results are considered normal if the organs and structures being examined look ok.

  • What Abnormal Results Mean
    • The meaning of abnormal results will depend on the part of the body being examined and the problem found. Talk to your health care provider about your questions and concerns.

  • Risks
    • There are no known risks. The test does not use ionizing radiation.

  • Considerations
    • Some types of ultrasound tests need to be done with a probe that is inserted into your body. Talk to your provider about how your test will be done.

  • References
    • Cosgrove DO, Lim A, Eckersley RJ, et al. Ultrasound. In: Adam A, Dixon AK, Gillard JH, et al. eds. Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging. 6th ed. New York, NY: Churchill Livingstone; 2014:chap 3.