What Is Ultrasound?
Ultrasound is like ordinary sound except it has a frequency (or pitch) higher than people can hear. Ultrasound is sent into the body from a scanning instrument (transducer) placed on a patient's skin. The sound is reflected off
structures inside the body and is analyzed by a computer to make a picture of these structures on a monitor similar to a television screen. The moving pictures are then recorded on film. Diagnostic ultrasound is also called sonography.

Who Performs an Ultrasound Examination?
In most clinical settings, a diagnostic medical sonographer—an allied health professional who has been trained specifically to perform ultrasound
examinations—will perform the examination. Following the completion of
the examination, the sonographer will review the images and the patient’s history with a doctor trained in the interpretation of ultrasound. Although a sonographer or a technologist may play a critical role in extracting the information essential to deriving a diagnosis, the rendering of a final diagnosis of ultrasound studies represents the practice of medicine, and, therefore, is
the responsibility of the radiologist.

Is Ultrasound Safe?
There are no known harmful effects associated with the diagnostic use of ultrasound. Widespread clinical use of diagnostic ultrasound for many years has not revealed any harmful effects. Although the possibility exists that such
biological effects may be identified in the future, current data indicate that the benefits to patients of the prudent use of diagnostic ultrasound outweigh
the risks, if any, that may be present. However, a prudent and conservative
approach is recommended in which diagnostic ultrasound is to be used only for medical benefit and with minimal exposure.

What Areas of the Body Can Be Imaged by Ultrasound?
Ultrasound is a safe and noninvasive diagnostic tool that can be used to examine many parts of the body, most commonly soft tissue. It is used extensively in the female pelvis (both obstetrical and gynecological), the abdomen (kidneys, liver, and gallbladder), and for cardiac diagnosis. Another type of ultrasound, Doppler, is used in vascular diagnosis to assess blood flow.
Other areas, such as the brain, eyes, thyroid, breast, prostate, and testicles, can be imaged by ultrasound as well.

Why is Ultrasound Used in Pregnancy?
Ultrasound is widely known for its use in first-, second-, and third-trimester pregnancy. The most common reason for having an ultrasound examination
during pregnancy is to help the doctor determine when a patient’s baby is due, or to make sure the baby is growing as it should. A doctor may also request an ultrasound examination to determine the baby’s position, to
see if the patient is carrying twins or triplets, or to detect a birth defect.

How Should Ultrasound Be Used?
Ultrasound should be used in a prudent manner, only to provide medical benefit to the patient. The AIUM strongly discourages the nonmedical use of ultrasound for psychosocial or entertainment purposes. The use of ultrasound
to only view the fetus, obtain a picture of the fetus, or determine the fetal gender without a medical indication is inappropriate and contrary to responsible medical practice.