What Is a Gallbladder Radionuclide Scan?
radionuclide scan is an imaging test that uses radiation to detect
infection, disease, bile fluid leakage, or blockage in your gallbladder. The
procedure uses radioactive “tracers” injected into your bloodstream that are
viewed under specialized imaging equipment.
The gallbladder is
a small organ underneath your liver that stores bile. Bile is a greenish or yellowish
liquid secreted by the liver that helps to digest and absorb fat. Even though
the gallbladder performs an important function, your body can survive without
The gallbladder radionuclide scan is also called hepatobiliary
imaging, or hepatobiliary iminodiacetic acid scan (HIDA).
Why Is a Gallbladder Radionuclide Scan
A gallbladder radionuclide scan is done to help detect potential
problems with your gallbladder or ducts near the gallbladder. Problems may
- bile duct blockage
- cholecystitis (gallbladder inflammation)
- bile leakage
- birth defects (in these cases, the scan is done
on newborns or young children)
The procedure can also be used to test your gallbladder ejection
fraction (the percentage of total bile
that gets produced during a certain period of time) and the rate at which your
gallbladder releases bile.
The Risks of a Gallbladder Radionuclide Scan
There is a risk of exposure to radiation with this test, as the
scan uses small amounts of radioactive tracers. However, this test has been
used for over 50 years and there are no known long-term side effects from such
low doses of radiation.
There is a rare chance of an allergic reaction, which is
Pregnant women or women who believe they could be pregnant should
not undergo the test. While the levels of radiation emitted by the tracers are
considered safe for adults, they are unsafe for developing fetuses. You should
tell your doctor if there is a chance that you are pregnant before agreeing to
have the scan.
How to Prepare for a Gallbladder Radionuclide Scan
Your doctor will give you complete instructions on how to prepare
for your gallbladder radionuclide scan. These instructions may include fasting
for four hours before the test.
At appointments before the scan, your doctor will perform a
physical examination and take your complete medical history. Tell your doctor
about any allergies you have and any medications you are taking, including
over-the-counter medications or nutritional supplements.
Let your doctor know if you have problems lying still for an
extended period, as the test can take up to 90 minutes.
How a Gallbladder Radionuclide Scan Is Performed
The procedure is typically done on an outpatient basis, which
means you can go home when your gallbladder radionuclide scan is complete.
The machine completing the scan looks like a large metal donut
with a table coming out of it. There will be two large, block-like objects in
front of the machine. These are part of the gamma camera that help doctors view
You’ll begin by removing all jewelry and changing into a hospital
gown. You will then lie flat on a scanning table. A trained specialist will
insert an IV needle into your arm and deliver a medication with radiotracers. The
tracers travel through your bloodstream, work their way into your gallbladder,
and move through the bile ducts attached to it.
When the medication (radionuclide) has properly absorbed into
your body, the scan portion of the test begins. The technician will slide you
into the machine feet-first and your head will remain outside of the machine. You
will be instructed to hold still while the scan is in progress. This may be
uncomfortable, but it helps the machine to achieve clear images. The machine
will pass back and forth over your abdomen while the gamma camera continuously
Your doctor will be watching the scan on a monitor as the tracers
move through your body. When the tracers reach your small intestines, the scan
After the scan, you’ll be instructed to drink plenty of water so
the excess radioactive tracers can be flushed from your body.
After a Gallbladder Radionuclide Scan
You may get your test results within hours (if your doctor
requested a stat reading), or your doctor may want to review them with you
The images from the scan are in black and white. Concentrated
dark areas signify the concentration of the radioactive tracers. If no tracers
are found on the scan or the scan moved slowly, there may be blockage issues or
problems with your liver. If the tracers are found in other areas, this could
indicate a leak.
If the results of your gallbladder radionuclide scan show
problems, your doctor may choose to take immediate action. This could include
surgery or medication. In all likelihood, you’ll undergo more testing so that your
doctor has a higher level of certainty regarding your condition.