Ultrasound

An abdominal ultrasound can provide pictures of structures and organs in the abdomen, such as the:

  • abdominal aorta, the large blood vessel that passes down the back of the chest and abdomen, just to the left of the backbone.
  • liver, a large dome-shaped organ that lies under the rib cage on the right side of the abdomen which produces bile.
  • gallbladder, a saclike organ beneath the liver which stores bile.
  • spleen, 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 lowest left rib.
  • pancreas, the gland located in the upper abdomen that produces enzymes that help digest food and also produces insulin.
  • Kidneys, the pair of bean-shaped organs located behind the upper abdominal cavity. The kidneys remove wastes from the blood and produce urine.

An abdominal ultrasound is performed in order to:

  • Detect, measure, or monitor an aneurysm in the aorta. An aneurysm may cause a pulsing lump in the abdomen.
  • Determine the cause of abdominal pain.
  • Detect gallstones or inflammation of the gallbladder.
  • Determine the size of an enlarged spleen and look for spleen damage or disease.
  • Detect problems with the pancreas such as pancreatitis or pancreatic cancer.
  • Evaluate the size, shape, and position of the liver or to detect liver masses, cirrhosis, fat deposits in the liver, or abnormal liver function tests.

An abdominal ultrasound may also be done to:

  • Help determine the cause of blocked urine flow in a kidney, determine the size of the kidneys, detect kidney masses, detect fluid surrounding the kidneys, investigate causes for recurring urinary tract infections, or to evaluate the condition of transplanted kidneys.
  • Determine whether a mass in any of the abdominal organs such as the liver is a tumor a simple fluid-filled cyst.
  • Determine the condition of the abdominal organs after an accident or abdominal injury.
  • Help guide the placement of a needle or other instrument during a biopsy.
  • Detect fluid buildup in the abdominal cavity or to guide the needle during a procedure to remove fluid from the abdominal cavity.

On the day of the test, tell your doctor if you have had a barium enema or a series of upper GI tests within the past 2 days. Barium that remains in the intestines can interfere with the ultrasound test. Other preparations depend on the reason for the abdominal ultrasound test you are having. For ultrasound of the liver, gallbladder, spleen, and pancreas, you may be asked to eat a fat-free meal on the evening before the test and then to avoid eating for 8 to 12 hours before the test. For ultrasound of the kidneys, you may not need any special preparation. You may be asked to drink 4 to 6 glasses of water about an hour before the test to fill your bladder. You may be asked to fast for 8 to 12 hours before the test if the gallbladder, spleen, and pancreas are to be evaluated also. For ultrasound of the aorta, you may need to avoid eating for 8 to 12 hours before the test.

An abdominal ultrasound is done by a doctor who specializes in performing and interpreting imaging tests (radiologist) or by an ultrasound technologist (sonographer). It is done in a hospital or doctor's office. You will need to remove any jewelry that might interfere with the test. You will need to take off all or most of your clothes, depending on which area is examined. You will be given a cloth or paper covering to use during the test. You will lie on your back or on your side on a padded examination table. Gel will be spread on your abdomen to improve the quality of the sound waves. The transducer is pressed against your abdomen and moved back and forth over it. A picture of the organs and blood vessels can be seen on a video monitor. You may be asked to change positions so additional scans can be made. For a kidney ultrasound, you may be asked to lie on your stomach. You need to lie very still while the ultrasound scan is being done. You may be asked to hold your breath for several seconds during the scanning. Abdominal ultrasound takes about 30 minutes. You may be asked to wait until the radiologist has reviewed the information. The radiologist may want to do additional ultrasound views of areas of your abdomen.

The gel may feel cold when it is applied to your stomach unless it is first warmed to body temperature. You will feel light pressure from the transducer as it passes over your abdomen. The ultrasound usually is not uncomfortable. There are no known risks from having an abdominal ultrasound test.