What is a hepatobiliary scan?
The liver is responsible for the removal of waste products from the body. Various waste products are excreted along with bile via the biliary tract. Bile can temporarily be stored in the gallbladder, ready for release when needed – bile is necessary for fat absorption.
Various abnormalities e.g. absence of the biliary tract, bulging of the tract etc. can be present from birth and need to be detected so that timeous intervention can be performed. These children will have symptoms e.g. severe yellow discoloration.
In other cases, an acute obstruction e.g. gallstone may impair biliary drainage which not only causes severe pain but may ultimately lead to liver damage.
Gallbladder inflammation can cause severe pain, obstruction of the gallbladder ducts and may even cause gallbladder perforation that can lead to abdominal sepsis and even death. Oftentimes a gallstone is responsible for this as well. This needs to be detected and treated as soon as possible.
Lignocaine is a substance that is rapidly removed from circulation by the liver cells, metabolized and then excreted in the bile. By changing the properties of this substance and adding a radioactive substance that emits gamma rays, we are able to image this process using a special machine called a gamma camera. This allows us to diagnose a variety of hepatobiliary diseases.
What can I expect to happen?
You are required to fast overnight (4-12 hours).
You will initially be imaged continuously for 1 hour. If the gallbladder is not visualized morphine sulphate will be administered to constrict the common bile duct outlet into the intestines. This increases the pressure in the common bile duct and
forces bile into the gallbladder. If you are allergic to morphine you will continue to be imaged hourly until 4 hours after the initial tracer administration.
If the gallbladder is visualized within 4 hours (or 1½ if the morphine sulphate method is used) acute cholecystitis (inflammation) is excluded. If visualization is delayed (i.e. requiring morphine or imaging up to 4 hours) then chronic cholecystitis is suspected. This is confirmed by administered a fatty meal or administered another hormone intravenously that cause the gallbladder to contract.
The gallbladder will then be imaged every 30 minutes for 90 minutes and this data used to determine the fraction excreted at each interval over the initial amount in the gallbladder (the ejection fraction). Should this number more than 34% at any stage before 60 minutes.
If visualization is prompt, both acute and chronic cholecystitis isexcluded.
All other indications follow a similar pattern. Patients may be required to return after 24 hours in some cases. This will be conveyed to you.
The nuclear physician will report the study.
