What is an ultrasound?

An ultrasound exam (also known as "sonography" or "ultrasonography") uses a small hand-held device called a "transducer" to direct high frequency sound waves to the area being scanned. These sound waves produce images of internal structures, such as organs and blood vessels, that can be viewed on a computer screen in real time. Most people are familiar with the sonographies that are performed on pregnant women, which allows the doctor to see the fetus in the womb. But ultrasound is also used to detect tumors in the body, possible blockages in blood flow, certain heart conditions, to guide needles during biopsy, as well as to detect other conditions, such as swelling and infection.

Patient undergoing ultrasound

Ultrasound of the kidney

What should I do to prepare for an ultrasound?

Wear comfortable, loose-fitting clothing, and remove any jewelry you may have on around the area being scanned. Depending on the type of scan you are having, there may be special special instructions you will need to follow prior to the exam, such as not eating or drinking. Your healthcare provider will give you a printout of those instructions.

What can I expect during an ultrasound?

The sonographer will help to position you on the examination table. A clear gel will be applied to the area being scanned to help the transducer glide easily over the skin. Either the sonographer or the radiologist will then move the transducer over the area of interest, while images of the internal structures are viewed on a computer screen.

In some cases where the physician may need to get clearer view certain internal organs, a probe attached to the transducer may be inserted into an opening in the body, such as the esophogas, rectum or vagina. A transesophogeal echocardiography involves inserting the probe into the esophogas to view the heart; a transvaginal ultrasound involves inserting the probe into the vagina to look at the uterus and ovaries; and a transrectal ultrasound is used to view the prostate by inserting the probe into the rectum.  

Ultrasound exams typically last between 20-30 minutes. If a biopsy is performed, it may take a little longer. Ultrasounds are also usually painless; however, sometimes discomfort can occur from the pressure being applied to the area.

Once the ultrasound is completed, the gel will be wiped off and you can return to normal activity.

Are ultrasound exams safe?

Because ultrasound uses sound waves instead of radiation to produce images, ultrasounds are considered very safe.

When will I get my results?

The radiologist will send the results of the scan to your physician, who will then discuss the results with you. In some cases, the radiologist or sonographer may also be able to give you feedback at the time of the exam.