Abdominal Ultrasound

An abdominal ultrasound uses reflected sound waves to produce a picture of the organs and other structures in the upper abdomen. Occasionally a specialized ultrasound is ordered for a detailed evaluation of a specific organ, such as a kidney ultrasound. An abdominal ultrasound can evaluate the:

Abdominal aorta, which is the large blood vessel (artery) that passes down the back of the chest and abdomen. The aorta supplies blood to the lower part of the body and the legs.
Liver, which is a large dome-shaped organ that lies under the rib cage on the right side of the abdomen. The liver produces bile (a substance that helps digest fat), stores sugars, and breaks down many of the body's waste products.
Gallbladder, which is a saclike organ beneath the liver. The gallbladder stores bile. When food is eaten, the gallbladder contracts, sending bile into the intestines to help in digesting food and absorbing fat-soluble vitamins.
Spleen, which is the soft, round organ that helps fight infection and filters old red blood cells. The spleen is located to the left of the stomach, just behind the lower left ribs.
Pancreas, which is the gland located in the upper abdomen that produces enzymes that help digest food. The digestive enzymes are then released into the intestines. The pancreas also releases insulin into the bloodstream; insulin helps the body utilize sugars for energy.
Kidneys, which are the pair of bean-shaped organs located behind the upper abdominal cavity. The kidneys remove wastes from the blood and produce urine.

Why It Is Done

Abdominal ultrasound is done to:

Determine the cause of abdominal pain.
Detect, measure, or monitor an aneurysm in the aorta. An aneurysm may cause a large, pulsing lump in the abdomen.
Evaluate the size, shape, and position of the liver. An ultrasound may be done to evaluate jaundice and other problems of the liver, including liver masses, cirrhosis, fat deposits in the liver (called fatty liver), or abnormal liver function tests.
Detect gallstones, inflammation of the gallbladder (cholecystitis), or blocked bile ducts. See an illustration of a gallstone.
Detect kidney stones.
Determine the size of an enlarged spleen and look for damage or disease.
Detect problems with the pancreas, such as pancreatitis or pancreatic cancer.
Determine the cause of blocked urine flow in a kidney. A kidney ultrasound may also be done to determine the size of the kidneys, detect kidney masses, detect fluid surrounding the kidneys, investigate causes for recurring urinary tract infections, or evaluate the condition of transplanted kidneys.
Determine whether a mass in any of the abdominal organs (such as the liver) is a solid tumor or a simple fluid-filled cyst.
Determine the condition of the abdominal organs after an accident or abdominal injury and look for blood in the abdominal cavity. However, computed tomography (CT) scanning is more commonly used for this purpose because it is more precise than abdominal ultrasound.
Guide the placement of a needle or other instrument during a biopsy.
Detect fluid buildup in the abdominal cavity (ascites). An ultrasound also may be done to guide the needle during a procedure to remove fluid from the abdominal cavity (paracentesis).