Abdominal Ultrasound: Purpose, Risk, Preparation, Procedure, and Follow-up

Updated: October 28, 2019

An abdominal ultrasound is performed to evaluate the organs and structures inside the abdomen including the abdominal aorta. It can be used to check for a number of conditions associated with abdomen. Most often this is the preferable screening method for detecting an abdominal aortic aneurysm, a weakened, bulging spot in your abdominal aorta. Usually, men ages 65 to 75 who are current or former cigarette smokers are recommended for an abdominal aortic aneurysm screening using this test.

Purpose of Abdominal Ultrasound:

Abdominal ultrasound is recommended if you are at risk of an abdominal aortic aneurysm. A one-time abdominal aortic ultrasound screening is recommended for men between the ages of 65 and 75 who current or former cigarette smokers. Routine screening for abdominal aortic aneurysm is neither recommended for women nor for for men who have never smoked.
Risk factors for abdominal aortic aneurysm include:

• Smoking cigarettes
• Being male
• Being age 65 or older
• Being white
• A history of atherosclerosis  which is thickening of the walls of your arteries
• A family history of abdominal aortic aneurysm
• High blood pressure (a systolic pressure of 140 to 159 millimeters of mercury, or mm Hg, or a diastolic pressure of 90 to 99 mm Hg)
• An aneurysm in one of your other arteries
• Obesity

Generally, abdominal ultrasounds are used to check the major organs in the abdominal cavity, including the gallbladder, kidneys, liver, pancreas, and spleen.
Abdominal ultrasound may be required if you have any of the following condition:

• blood clot
• enlarged organ (such as the liver, spleen, or kidneys)
• fluid in the abdominal cavity
• gallstone
• hernia
• pancreatitis
• kidney stone
• kidney blockage or cancer
• appendicitis
• liver cancer
• tumors

Abdominal ultrasounds may also be used to help guide your doctor during certain procedures. For example:

• During an abdominal biopsy, where remove a small sample of tissue is required to remove, your doctor may use ultrasound to find the exact location and see where to place the needle.
• Ultrasounds can help your doctor drain fluid from a cyst or abscess.
• It can be used to examine blood flow inside your abdomen.

Risk of Abdominal Ultrasound:

An abdominal ultrasound has no risks. Unlike X-rays or CT scans, ultrasounds does not use any radiation. This is reason, it is preferable to use in pregnant women to check on developing babies. Real-time images of the fetus can be seen using fetal ultrasound imaging. Although there is minimal risk in this, it is advisable to have ultrasound scans only when there is a specific medical need. This is to avoid unnecessary exposure of extra ultrasounds to the fetus .
Ultrasound imaging and heartbeat monitors do not cause any harm to fetuses. However, ultrasound can heat tissues in the abdomen slightly, which can make very small bubbles in some tissues in some cases. The long-term effects of this is not known.

Preparation for an Abdominal Ultrasound:

Fasting for eight to 12 hours before your ultrasound is required for this test. This is because undigested food can block the sound waves, making it difficult to get a clear picture for the technician.
For an examination of the gallbladder, liver, pancreas, or spleen, you need to eat a fat-free meal the evening before your test and then to fast until the procedure. However, you can drink water and take any medications as instructed by your doctor.
You need to drink several glasses of water in the time leading up to the test and hold your urine to ensure that your bladder is full to get better visualized images.
Make sure to inform your doctor about any prescription drugs, over-the-counter medications, or herbal supplements that you take before the examination.

Procedure for an Abdominal Ultrasound:

You should wear comfortable clothing that is easy to remove or partially remove if required. In some cases, you may need to take off your clothes or wear a gown.
But often the area of the body that is being screened can easily access by the ultrasound technician without taking off your clothes.
A water-based gel will be applied to the area by the technician so that the transducer can easily glide across your skin without any air in between. The gel also helps transmit the sound waves. Presence of any specific markers will be noticed and measurements will be taken while the test is in progress.
A typical ultrasound takes between 30 minutes to one hour. Usually you won't feel any kind of discomfort during the test, and you are awake and alert during the procedure. Often a technician will discuss what he or she is seeing during the test, but in some instances, you may need to wait to discuss the findings with your doctor.
An instrument called a transducer which looks similar to a microphone emits high-frequency sound which will not audible to human ears. The waves echo as they hit a dense object, such as an organ or bone. Those echoes are then reflected back into a computer. It then records the echoes to determine the size, shape, and consistency of soft tissues and organs.This information is relayed in real time to produce images on a computer screen. Ultrasound technicians or sonographers usually perform the test who have special training in the technique. You may need to change positions depending on the area being examined,so that the technician can have better access.
A radiologist or your doctor can interpret the ultrasound images. This technology can help diagnose and treat certain conditions. The gel will be cleaned off of your skin after the procedure and you can get back to your normal activities. 
Certain factors or conditions may interfere with the results of an ultrasound. These may include:

• severe obesity
• food inside the stomach
• leftover barium in the intestines from a recent barium procedure. Barium is a liquid that you swallow in some tests which helps your doctor see your stomach and gastrointestinal tract.
• excess intestinal gas

Follow-up:

Your doctor will review the images and check for any abnormalities after the examination. The findings will be discussed with you. If your doctor is able to make a diagnosis of your condition based on your ultrasound of the abdomen, they may begin your treatment immediately. Else, you may need to undergo other diagnostic techniques, such as a CT scan, MRI, or a biopsy sample of tissue depending on the area examined, if any abnormality is found and can not get diagnosed with the result of ultrasound alone.