Ultrasound

An ultrasound (US) is a radiology test that makes pictures of organs inside your body. The US makes the pictures using sound waves. A probe is pressed against your skin and waves are created. As these sound waves bounce off your organs and return to the probe, a computer draws up the pattern. The computer then uses the pattern to create an image that can be read by your provider. US waves work well in parts of the body that are made up of tissue or water. US does not work well in areas of the body where there is air or bone, such as the lungs or head.

Why is an ultrasound done?

Ultrasound is most often used to look at a growing baby. It can also be used to see:

• Organs in your belly (liver, kidney, gallbladder).
• Your heart and blood vessels (arteries and veins).
• Lymph nodes.
• A mass more clearly during a biopsy.
• How much urine is in your bladder.

Ultrasounds can be used in emergency situations, like looking for blood in the belly, a blood clot in the leg, or any changes or problems in the heart. Most often ultrasounds are done non-emergently and scheduled as an outpatient procedure. They can be used with a physical exam and lab work to diagnose a medical problem.

How do I prepare for an ultrasound?

How you prepare for an US depends on the part of your body that needs testing. In some cases, you don’t need to prepare. Other times, you may be asked not to eat or drink for up to 12 hours before the test, or you may need to drink up to six glasses of water two hours before the test.

If the US will be placed rectally (into your rectum) for a prostate biopsy, you may need to clear stool from your bowel. If the scope will be placed endoscopically (through the mouth and esophagus) or bronchoscopically (into the lungs), you will be asked to fast (not eat) to prepare for the sedation medications (that help you calm down).

Your provider will tell you before the test how to prepare for your US.

How is this test done?

You will likely be asked to put on a hospital gown. Your position on the table depends on the part of your body being looked at. Gel will be placed on your skin to allow the probe to make better contact with your skin. The technician will then place a transducer or probe on your skin on top of the area being looked at. The probe makes sound waves that travel into the tissue and then reflect off tissues inside your body and return to the probe.

The test may cause discomfort in some cases but not pain. It only takes 20-40 minutes to complete, depending on the size of the area being looked at.

How do I get the results of my ultrasound?

The radiologist (a doctor who specializes in medical imaging) writes a report for your healthcare provider who ordered the US. The report will give both normal and abnormal findings. Your provider will be able to talk with you about your results.