Alternative Names:- Ultrasound – abdomen; Abdominal sonogram
Abdominal ultrasound is an imaging procedure used to examine the internal organs of the abdomen, including the liver, gallbladder, spleen, pancreas, and kidneys. The blood vessels that lead to some of these organs can also be looked at with ultrasound.
It 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.
A pelvic ultrasound evaluates the structures and organs in the lower abdominal area (pelvis).
Why It Is Required to be Done:-
The specific reason for the test will depend on your symptoms. Abdominal ultrasound is mostly 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).
How the Test is Performed :-
This test is done by a doctor who specializes in performing and interpreting imaging tests (radiologist) or by an ultrasound technologist (sonographer) who is supervised by a radiologist. It is done in an ultrasound room in a hospital or doctor’s office.
You will need to remove any jewelry that might interfere with the ultrasound scan. You will need to take off all or most of your clothes, depending on which area is examined (you may be allowed to keep on your underwear if it does not interfere with the test). You will be given a cloth or paper covering to use during the test.
An ultrasound machine creates images that allow various organs in the body to be examined. The machine sends out high-frequency sound waves, which reflect off body structures to create a picture. A computer receives these reflected waves and uses them to create a picture. Unlike with x-rays or CT scans, there is no ionizing radiation exposure with this test.
You will be lying down for the procedure. A clear, water-based conducting gel is applied to the skin over the abdomen. This helps with the transmission of the sound waves. A handheld probe called a transducer is then moved over the abdomen.
You may be asked to change position so that the health care provider can examine different areas. You may also be asked to hold your breath for short periods of time during the examination.
Abdominal ultrasound usually takes 30 to 60 minutes. You may be asked to wait until the radiologist has reviewed the information. The radiologist may want to do additional ultrasound views of some areas of your abdomen.
How To Prepare For the Test:-
Tell your doctor if you have had a barium enema or a series of upper GI (gastrointestinal) tests within the past 2 days. Barium that remains in the intestines can interfere with the ultrasound test.
Preparation for the procedure depends on the nature of the problem and your age. Usually patients are asked to not eat or drink for several hours before the examination. Your health care provider will advise you about specific preparation.
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 liquid (usually juice or water) about an hour before the test to fill your bladder. You may be asked to avoid eating for 8 to 12 hours before the test to avoid gas buildup in the intestines. This could interfere with the evaluation of the kidneys, which lay behind the stomach and intestines.
For ultrasound of the aorta, you may need to avoid eating for 8 to 12 hours before the test.
How It Feels:-
There is little discomfort. The conducting gel may feel slightly cold and wet 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. However, if the test is being done to assess damage from a recent injury, the slight pressure of the transducer may be somewhat painful. You will not hear or feel the sound waves.
There is no documented risk. No ionizing radiation exposure is involved.
An abdominal ultrasound uses reflected sound waves to produce a picture of the organs and other structures in the abdomen.
Abdominal ultrasound Normal:
The size and shape of the abdominal organs appear normal. The liver, spleen, and pancreas appear normal in size and texture. No abnormal growths are seen. No fluid is found in the abdomen.
The diameter of the aorta is normal and no aneurysms are seen.
The thickness of the gallbladder wall is normal. The size of the bile ducts between the gallbladder and the small intestine is normal. No gallstones are seen.
The kidneys appear as sharply outlined bean-shaped organs. No kidney stones are seen. No blockage to the system draining the kidneys is present.
Abdominal ultrasound Abnormal:
An organ may appear abnormal because of inflammation, infection, or other diseases. An organ may be smaller than normal because of an old injury or past inflammation. An organ may be pushed out of its normal location because of an abnormal growth pressing against it. An abnormal growth (such as a tumor) may be seen in an organ. Fluid in the abdominal cavity (ascites) may be seen.
The aorta is enlarged, or an aneurysm is seen.
The liver may appear abnormal, which may indicate liver disease (such as cirrhosis or cancer).
The walls of the gallbladder may be thickened, or fluid may be present around the gallbladder, which may indicate inflammation. The bile ducts may be enlarged because of blockage (from a gallstone or an abnormal growth in the pancreas). Gallstones may be seen inside the gallbladder.
The kidneys may be enlarged because of urine that is not draining properly through the ureters. Kidney stones are seen within the kidneys (not all stones can be seen with ultrasound).
An area of infection (abscess) or a fluid-filled cyst may appear as a round, hollow structure inside an organ. The spleen may be ruptured (if an injury to the abdomen has occurred).