(Cholescintigraphy, Liver-Biliary Scan, Hepatobiliary Iminodiacetic Acid [HIDA], Gallbladder Radionuclide Scan)
What is a gallbladder scan?
A gallbladder scan is a specialized radiology procedure used to assess the function and structure of the gallbladder. This procedure may also be referred to as a liver-biliary scan because the liver often is examined as well due to its proximity and close functional relationship to the gallbladder.
A gallbladder scan is a type of nuclear radiology procedure. This means that a tiny amount of a radioactive substance is used during the procedure to assist in the examination of the gallbladder. The radioactive substance, called a radionuclide (radiopharmaceutical or radioactive tracer), is absorbed by normal gallbladder tissue.
The radionuclide used in gallbladder scans is usually a form of technetium. Once absorbed into the gallbladder tissue, the radionuclide emits a type of radiation, called gamma radiation. The gamma radiation is detected by a scanner, which processes the information into a picture of the gallbladder.
By measuring the behavior of the radionuclide in the body during a nuclear scan, the physician can assess and diagnose various conditions, such as obstruction of bile ducts from gallstones, tumors, abscesses, hematomas, organ enlargement, or cysts. A nuclear scan may also be used to assess organ function and blood circulation.
The areas where the radionuclide collects in greater amounts are called "hot spots." The areas that do not absorb the radionuclide and appear less bright on the scan image are referred to as "cold spots."
Gallbladder disease may be caused by infection or by a blockage within the gallbladder or the ducts of the liver/gallbladder system (the biliary tree). If the gallbladder is infected, the radionuclide cannot be absorbed by the gallbladder. If there is a blockage within the biliary tree, absorption of the radionuclide will stop at the point of the obstruction.
Other related procedures that may be used to diagnose problems of the gallbladder include abdominal x-rays, computed tomography (CT scan) of the liver and biliary tract, abdominal ultrasound, cholecystography, or endoscopic retrograde cholangiopancreatography (ERCP). Please see these procedures for additional information.
About the gallbladder:
The gallbladder is a pear-shaped organ located near the right lobe of the liver. The gallbladder stores and concentrates bile, a substance produced by the liver and used to break down fat for digestion.
Reasons for the Procedure
A gallbladder scan may be performed in situations where gallbladder disease (cholecystitis) is suspected, such as with severe acute right upper abdominal quadrant pain or when jaundice (yellowed skin and/or eyes) is present. Elevated liver enzymes in a specific blood test may also indicate some type of gallbladder disease.
A gallbladder scan may also be helpful in diagnosing biliary duct obstructions and determining gallbladder function.
There may be other reasons for your physician to recommend a gallbladder scan.
Risks of the Procedure
The amount of the radionuclide injected into your vein for the procedure is small enough that there is no need for precautions against radioactive exposure. The injection of the radionuclide may cause some slight discomfort. Allergic reactions to the radionuclide are rare, but may occur.
For some patients, having to lie still on the scanning table for the length of the procedure may cause some discomfort or pain.
Patients who are allergic to or sensitive to medications, contrast dyes, or latex should notify their physician.
If you are pregnant or suspect that you may be pregnant, you should notify your physician due to the risk of injury to the fetus from a gallbladder scan. If you are lactating, or breastfeeding, you should notify your physician due to the risk of contaminating breast milk with the radionuclide.
There may be other risks depending upon your specific medical condition. Be sure to discuss any concerns with your physician prior to the procedure.