Ultrasound scans use high frequency sound waves to capture live images and video. This helps doctors view the inside of your body. Abdominal ultrasounds are used to help your doctor visualize the organs and structures (in detail) inside the abdomen.
Ultrasounds are safe and painless. They’re also increasingly common — more and more ultrasounds are performed in the United States every year. One study found that the number of ultrasounds done in the United States grew by 4 percent every year from 1996 to 2010.
Ultrasound images are captured in real time and are able to show the structure and movement of the body’s internal organs, as well as blood flowing through the blood vessels. Just as sonar and radar help the military detect planes and ships, ultrasound helps doctors understand what’s going on inside your body. This test is most commonly used on pregnant women to view and examine their fetuses, but there are numerous other clinical uses as well.
Abdominal ultrasounds are used to check the major organs in the abdominal cavity. These organs include your gallbladder, kidneys, liver, pancreas, and spleen.
Your doctor may have you do an abdominal ultrasound if they suspect you have a variety of conditions, including:
- abdominal aortic aneurysms
- blood clots
- enlarged organs (such as liver, spleen, or kidneys)
- fluid in the abdominal cavity
- kidney blockage or cancer
- kidney stones
- liver cancer
Abdominal ultrasounds may also be used to help your doctor find where to place the needles used to remove tissue from the abdomen so they can test it (a procedure known as a biopsy) or to drain fluid from cysts or abscesses. It can also be used to examine the blood flow inside the abdomen.
According to the Mayo Clinic, men ages 65 to 75 who are current or former smokers should be screened with an abdominal ultrasound to check for an abdominal aortic aneurysm.
An abdominal ultrasound has no risks. Unlike X-rays or CT scans, ultrasounds use no radiation, which is why doctors prefer to use them with pregnant women to examine fetuses.
You may feel slight discomfort during the procedure if you’re experiencing pain in your abdomen. You should let your technician know right away if the pain becomes severe.
Certain factors or conditions may interfere with the results of the test, including:
- severe obesity
- food inside the stomach
- leftover barium (a liquid you swallow in some tests that helps your doctor see your stomach and gastrointestinal tract) still in the intestines from a recent barium procedure
- excess intestinal gas
Ultrasound imaging is the most widely used medical imaging method during pregnancy. Fetal ultrasound imaging provides real-time images of the fetus. Though the pictures can be exciting keepsakes for parents-to-be, the U.S. Food and Drug Administration advises parents to skip any unnecessary scans.
Although there is no evidence of any harm done to fetuses from ultrasound imaging and heartbeat monitors, doctors still can’t be sure that there aren’t any longer terms risks. Ultrasound can heat tissues in the abdomen slightly, and in some cases, it can also produce very small bubbles in some tissues. The exact long-term effects of this aren’t known.
It’s best to do ultrasound scans only when there is a specific medical need. Ultrasound scans should be performed by appropriately trained operators. There is no medical benefit gained from exposing the fetus to unnecessary extra ultrasounds, so the FDA advises against these “keepsake videos.”
Your doctor will usually tell you to fast for eight to 12 hours before your ultrasound. This is because undigested food can block the sound waves, making it difficult for the technician to get a clear picture.
You should, however, continue to drink water and take your medications as instructed by your doctor.
There are some exceptions when the ultrasound is to examine the gallbladder, liver, pancreas, or spleen. You may be instructed to eat a fat-free meal the evening before your test, before beginning your fast.
Before the exam, you will be asked to remove any clothing, jewelry, or other objects that might interfere with the scan and change into a hospital gown. You will begin the scan by lying down on a table with your abdomen exposed.
An ultrasound technician (sonographer) will apply a special lubricating jelly, or gel, to your abdomen. This is done to prevent friction while they rub the ultrasound transducer, which looks like a microphone, on your skin to help transmit the sound waves.
The transducer sends high frequency sound waves through your body. These waves, which are too high-pitched for the human ear to hear, echo as they hit a dense object, such as an organ. Those echoes are then reflected back into a computer.
Depending on the area being examined, you may need to change positions so the technician can better access those areas.
When the scan is done, the gel will be cleaned off of your abdomen. After the procedure, which usually lasts less than 30 minutes, you’ll be free to go about your day.
A radiologist will interpret your radiology examination. He or she will analyze the images and send the report to your doctor. Your doctor will discuss with you the results at a follow-up appointment. They’ll also talk to you about any treatment options if the test turns up anything of note. Depending on what your scan shows, you may need another exam conducted if anything suspicious or questionable was found. Your doctor may ask for another follow-up scan and appointment to help monitor any issues that were found.