Ultrasound Scanning

Perhaps the most well known use of ultrasound scanning is a common exam used for pregnancy, called ultrasound or sonogram.  The ultrasound scan may be done for different reasons at different stages of the pregnancy.  Some of them are:

• to make sure the baby is developing inside the uterus and not in a fallopian tube
• to determine how far along the pregnancy is
• to estimate the size, weight, and position of the baby
• to see if the placenta is normal and attached properly
• to see if the baby has any major physical abnormalities
• to check for one or more babies
• to check the amount of fluid inside the uterus
• to check the baby's heart

Other uses for ultrasound scanning include determining disease and structural abnormalities when examining other areas of the body such as the:

• heart
• thyroid gland
• testicles
• abdomen and
• arms or legs

An ultrasound of the abdomen examines a number of organs in the body including the gall bladder, liver, spleen, pancreas, and the kidneys.  Each of these organs may be tested separately.  A special ultrasound scan of the heart is called an echocardiography.

GENERAL PREPARATIONS for ultrasound scanning include:

• removal of all clothing and jewelry from the area to be scanned and
• application of a gel or oil to the skin of the area to be scanned

Certain SPECIALIZED ultrasound scans require ADDITIONAL PREPARATIONS such as:

• for abdominal ultrasound, not eating or drinking for at least 8 hours
• for ultrasound that is being used with a needle biopsy, a local anesthetic may be injected into the tissue to be scanned
• for an echocardiography, small metal discs, called electrodes are placed on the arms and legs.
• for pregnancy ultrasound, drinking up to 6 glasses of water an hour before the test and then not urinating until after the test is necessary

Generally, an ultrasound scan takes 30 to 60 minutes to complete.  The procedure is done in a hospital or medical clinic usually on an out-patient basis.  This means the patient can go home soon after the procedure.

With most types of ultrasound, a small device called a transducer is placed on the skin over the part of the body to be examined.  The transducer is passed back and forth over the skin, gliding smoothly on the lubricating gel or oil.  The sound waves leave the transducer and pass into the body. They are then reflected back to the transducer, which picks them up and relays them to a computer for analysis and creation of a still or moving picture.

The patient is free to go home and begin all normal activities immediately after the scan is over.  Results may be available from within a few minutes to a few days later.

There are no known risks associated with ultrasound scanning techniques because the sound waves used are not dangerous.  However, if it is necessary to use anesthesia or to insert a medical instrument into the body to conduct the ultrasound, there may be a slight risk associated with the procedure.

It is possible that good images may not be obtained in every case and the scan may not produce as precise results as some other diagnostic imaging procedures.  In addition, scan results may be affected by:

• physical abnormalities
• chronic disease
• excessive movement or
• incorrect transducer placement

There are no known side effects, even for pregnant women and children, who can not have x-rays.  In addition, no medications are known to interfere with test results.  Ultrasound scanning is fast, painless, involves no radiation, and avoids possible hazards (such as bleeding, infection, or reactions to chemicals) of other diagnostic methods.

Disclaimer:  This content is reviewed periodically and is subject to change as new health information becomes available.  The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.