A HIDA scan (hepatobiliary iminodiacetic acid) is an imaging process used to evaluate the functioning of the liver, gall bladder, and bile ducts. It can be quite useful in diagnosing conditions like biliary atresia, biliary leak, and cholecystitis. This procedure is done using a scanning camera and tracer chemical. The procedure is also known as a hepatobiliary scintigraphy and cholescintigraphy. The scan’s report is often analyzed along with an X-ray and ultrasound result.

Preparing for the scan
There are a few things to consider before undergoing a HIDA scan. The healthcare provider will suggest fasting for four hours and will ask the individual to have clear liquids only. Make sure to inform the healthcare provider about any supplements and treatments that one is taking. The physician must also be aware about whether a person undergoing the scan is pregnant or breastfeeding.

After the individual reaches the hospital, the imaging technician will ask them to wear the hospital gown. They will then have to remove all jewelry and metal accessories before getting started with the scan.

Procedure
The scan may be conducted in the following way:

• The individual needs to lie back on a table, and needs to stay very still.
• The scanner will be placed above the belly.
• The technician adds the radioactive tracer into the IV so that it enters the blood.
• A series of images are taken by the scanner as the tracer moves inside the body.
• The technologist will inform the individual if there is a need to change positions during the image-taking procedure. In this step, once the initial images have been taken, the urinary bladder is made empty, and after that, more images are taken. The entire process may take up to four hours.

Results
The result of this scan depends upon the way in which the radioactive tracer moved in the biliary system. Healthcare providers use blood tests along with this scan’s results to diagnose certain conditions. The results can be interpreted as follows:

Normal
Here, the radiotracer goes along freely with the bile, moving from the liver into the gall bladder and small intestine.

Slow
The tracer moves more slowly than normal in the body. It may be a sign of a problem or blockage within the liver.

Not present
It means that there is no radiotracer visible in the gall bladder, which may indicate that the individual is suffering from gall bladder inflammation or acute cholecystitis.

Low gallbladder ejection fraction
It may indicate that the individual has chronic cholecystitis or chronic gallbladder inflammation.

Radioactive tracer in other body parts
This may indicate a leakage in one’s biliary system.

Purpose
A HIDA scan is mainly used to diagnose the following conditions:

Acute cholecystitis
Also known as gallbladder inflammation, it appears suddenly and leads to serious pain in the upper right part of the belly. This condition may also include other symptoms like fever.

Chronic cholecystitis
This condition is characterized by repeated inflammation attacks and pain in the gallbladder. One experiences such symptoms because of the blockage of the cystic ducts by the gallstones.

Biliary atresia
Biliary atresia occurs in newborn babies. The bile does not flow from the liver to the gall bladder. It is a rare condition and can lead to severe jaundice. This can progressively result in liver cirrhosis.

Biliary leak
This condition leads to the leaking of bile from any of the ducts in the biliary system. Such leakages lead to pain, inflammation, and infection in the surrounding area. It generally happens after a liver transplant, trauma or injury, and gallbladder surgery.

Sphincter of Oddi dysfunction
This occurs when the sphincter muscles fail to open when they should; hence, resulting in a backup of intestinal juices. This can lead to serious pain.

Cost
The price of the scan can range from $1,120 to $1,400. It will depend on one’s location, type of insurance, and the hospital at which the scan is done.

Risks and side effects
This scan may have a few side effects and risks, which are detailed below:

• Bruising may occur at the radiotracer’s injection site
• Though it is rare, allergic reactions may happen to the substances contained in the radiotracer that is used for the scan.
• Radiation exposure can also occur.

A HIDA scan is an important test for diagnosing and evaluating certain conditions or problems in the liver, gall bladder, and bile ducts. This procedure is largely painless, except for a minor pinching feeling when the hospital staff places the IV into the arm.