What Is a Hepatobiliary (HIDA) Scan And How Is It Conducted?

Submitted on March 27, 2012

Hepatobiliary scan or HIDA scan is conducted to examine the functioning of the liver. It checks if bile is being made and excreted, if the bile ducts or drainage system are functioning appropriately, and if there is any malfunction in the gallbladder. Typically, a hepatobiliary scan is coupled with an ultrasound of the gallbladder for a comprehensive evaluation. HIDA scan is also referred to as a hepatobiliary iminodiacetic acid scan or an NM hepatobiliary scan. This scan is an imaging process through which your doctor can track bile movements, its production and its flow into the small intestines from you liver. Basically, this scan generates pictures of your biliary tract, liver, gallbladder, and small intestine. It falls under the imaging study called nuclear medicine scans (NM scans). Nuclear medicine scans use a tracer, which are radioactive chemicals to highlight particular organs in the imaging scans.

The liver is one of the most complicated organs of the human body. This organ is responsible for many different functions including some functions on which the life of the individual depends. No person can live without a liver that is partially functional. One of the many different functions of the liver is the production of bile. Bile is a fluid that is used to break down fatty foods in the digestive system. This fluid is produced in the liver and passed into the gall bladder where it is stored until the individual needs to digest food. When digestion takes place, bile flows directly from the liver into the small intestine. At the same time, bile from the gall bladder will also enter the area. This increases the amount of bile available, thus ensuring that even large quantities of food get broken down effectively.

What Is a Hepatobiliary Scan?

The hepatobiliary scan is a scan used to determine the effectiveness of the liver’s functioning, particularly relating to its production and release of bile. A person may even have to go through a hepatobiliary scan with gallbladder ejection fraction in certain cases. The hepatobiliary scan is a nuclear medicine scan. This means that a radioactive tracer substance needs to be injected into the body. Tracer substances are used to mark out various organs and tissues in the body. This makes it possible for them to be seen clearly on any subsequent scan. The liver is used to filter out waste products from the blood. Thus, the tracer material will make the parts of the liver very clear in any scan.

The hepatobiliary scan is done in order to check if there is any obstruction in the bile ducts of the liver. This scan is also done to check if there is any obstruction or inflammation of the gall bladder. There may even be a situation where bile leaks into the intestines when it is not needed for digestion. This sort of test will be able to determine if that is the case.

Reason Why is it Ordered?

HIDA scans assist in the diagnosis of conditions or diseases like bile leakage, cholecystitis or gallbladder inflammation, bile duct blockage, congenital abnormalities in you bile ducts, and gallstones. Doctors also order an HIDA scan to measure gallbladder ejection fraction, that is, measuring the rate of bile release from the gallbladder.

Preparation

You cannot eat or drink anything at least 6 hours before the scan, so it is best you schedule this test early in the morning. Keep your doctor informed about any medications you are taking. Usually, pain medications have to stop 6 hours before the test. But, do not discontinue any medication without checking with your doctor. Also, if you have any allergies to medications or particular substances, keep your doctor informed. Additionally, the lab needs to be informed if you are pregnant or suspect a pregnancy.

Side Effects

You could have the entire hepatobiliary scan protocol explained to you before the procedure takes place. The hepatobiliary scan cpt code could be taken from the doctor. The hepatobiliary function scan is not without its side effects. The actual scanning process does not create any problems for the individual as this scan is non-invasive in nature. However, the process of injection of the contrast material can cause some problems. The individual can experience hepatobiliary scan side effects in the form of an allergic reaction to the contrast material that is used. This can even be catastrophic in nature which is why all such scans are done in hospital where there is scope for emergency medical intervention. The likelihood of this, though, is very low. A more likely problem associated with the hepatobiliary scan is the development of an infection in the area where the needle is used to inject the contrast material. One need not worry about the amount of radiation released by the scanning cameras or by the tracer dye that is injected into the body. This level of radioactivity is negligible and should not cause any health problems to the individual.

As one can see, simple medical practices of cleanliness and sanitization should eliminate the risk of an infection developing in the wound side. Thus, the hepatobiliary scan is a fairly risk free test that can be performed by any individual without much fear of side effects. The preparation needed for a hepatobiliary scan involve fasting for a few hours before the test. This will ensure that the flow of bile has stopped. One must discuss the duration of the fast with a doctor who can give the patient the correct recommendation. One must also report any medications that are being taken to the doctor. This will ensure that any medication that can affect the accuracy of the test is eliminated from the system before the test.

Hepatobiliary Scan with CCK

Before we go into the process of the scan, CCK or cholecystokinin a substance is injected through an IV to contract your gallbladder and assist in accurate capturing of gallbladder functioning. Hence, HIDA scans are also referred to as cholecystokinin hepatobiliary scans.

As the procedure begins, you would need to be in the supine position. A radioactive chemical (tracer) will be injected through an IV line in a vein in your arm. Cameras will be positioned over the table, above your gallbladder, to be precise, and images will be recorded for 60 to 90 minutes. The injected tracer will highlight areas of the gallbladder and make it visible to the NM camera. The camera captures images every few minutes to track gallbladder enlargement. This takes about an hour after which, CCK is injected to contract your bladder thereby highlighting gallbladder functioning for image capture.

There is no need to worry about the injected material, as it clears through the body in a few hours. Consuming plenty of fluids can help flush out the tracer even quicker. The whole scan process takes anywhere between 90 minutes to a couple of hours. Unless told otherwise, you can resume normal activities after the test.

Hepatobiliary scan results. Normal results imply that there is no dysfunction in the size, function or shape of the gallbladder. It also means that the bile ducts are not damaged nor are there any signs of blockage.

Results Explained

The scan results would be abnormal in the following cases:

  • When the tracer is still present in your bloodstream and hasn't been cleared by the liver,
  • When the tracer is unable to reach your gallbladder, and/or
  • When the tracer does not reach the small intestines.
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