What is a gallbladder scan?
A gallbladder scan is an imaging test to look at your gallbladder and see how well it is working. This test may also be called a liver-biliary scan because the healthcare provider often looks at the liver at the same time. The liver is near the gallbladder and works closely with it.
A gallbladder scan is a type of nuclear imaging test. This means that a tiny amount of a radioactive matter is used during the scan. The radioactive matter (radioactive tracer) is absorbed by normal gallbladder tissue. The radioactive tracer sends out gamma rays. These are picked up by the scanner to make a picture of your gallbladder.
The areas of the gallbladder where the radioactive tracer collects in greater amounts are called "hot spots." The areas that do not absorb the tracer and appear less bright on the scan image are referred to as "cold spots."
Why might I need a gallbladder scan?
You may need a gallbladder scan if your healthcare provider thinks you may have gallbladder disease (cholecystitis). Symptoms of gallbladder disease include:
- Sudden severe pain in the upper right area of your belly
- Yellowed skin or eyes (jaundice)
A blood test may also show higher levels of liver enzymes.
A gallbladder scan may also help diagnose blockages in the biliary duct. It can also tell your healthcare provider how well your gallbladder is working.
Your provider may have other reasons to recommend a gallbladder scan.
What are the risks of a gallbladder scan?
The risk from the radioactive tracer is very low. The amount used in the test is very small. You may feel some slight discomfort when the tracer is injected. Allergic reactions to the tracer are rare, but they may happen.
Lying on the scanning table during the procedure may cause some discomfort or pain for certain people.
Tell your healthcare provider if you:
- Are allergic to or sensitive to medicines, contrast dyes, or latex.
- Are pregnant or think that you might be pregnant. The scan may not be safe for the fetus.
- Are breastfeeding. The tracer may contaminate your breast milk.
You may have other risks that are unique to you. Be sure to discuss any concerns with your healthcare provider before the procedure.
Certain things may make a gallbladder scan less accurate. These include:
- Having radioactive tracer in your body from another recent nuclear medicine test
- Eating or drinking within 2 to 8 hours of the scan
- Going without food (fasting) for longer than a day (24 hours)
- Getting nutrients as a liquid given through a vein (hyperalimentation)
- Liver disease
Tell your healthcare provider if any of these apply to you.
The scan may also be less accurate if you have a blockage in your gallbladder. The blockage can stop the tracer from reaching your gallbladder. If you have a blockage in the ducts of the gallbladder or liver (biliary tree), the tracer will stop at that point.
How do I get ready for a gallbladder scan?
- Your healthcare provider will explain the procedure to you. Ask him or her any questions you have about the procedure.
- You may be asked to sign a consent form that gives permission to do the procedure. Read the form carefully and ask questions if anything is not clear.
- You will be asked to stop eating and drinking (fast) for up to 8 hours before the test. You should not fast any longer than your provider tells you to. Fasting too little or too long can affect how accurate your test is.
- Tell your provider if you are allergic to or sensitive to latex, medicines, contrast dyes, or iodine.
- Tell your provider if you are pregnant or think you may be pregnant.
- Follow any other instructions your provider gives you to get ready.
What happens during a gallbladder scan?
You may have a gallbladder scan done as an outpatient or as part of your stay in a hospital. The way the test is done may vary depending on your condition and your healthcare provider's practices.
Generally, a gallbladder scan follows this process:
- You will be asked to remove any clothing, jewelry, or other objects that may get in the way of the procedure.
- You will be asked to remove clothing. You will be given a gown to wear.
- An intravenous (IV) line will be started in your hand or arm so that you can be given the radioactive tracer.
- The radioactive tracer will be injected into your vein.
- You will be asked to lie still on a scanning table. You will need to stay still during the scan. If you move, it may affect the quality of the scan.
- The scanner will be placed over your belly. The technologist will take a series of images until he or she can see the gallbladder.
- In some cases, you may get an IV injection of morphine during the scan. This helps move the radioactive tracer into the gallbladder.
- If the radioactive tracer does not enter the gallbladder within a certain period of time, the scan may be done again within a few hours. This will let the technician see if you have a complete or partial blockage in the biliary tree.
- When the scan is done, the IV line will be removed.
The gallbladder scan is not painful. But you may have some discomfort or pain from lying still during the test. This may because of recent surgery or a joint injury. The technologist will use all possible comfort measures and do the scan as quickly as possible to minimize any discomfort or pain.
What happens after a gallbladder scan?
You should move slowly when getting up from the scanner table to avoid any dizziness or lightheadedness.
You may be told to drink plenty of fluids and empty your bladder often for 1 to 2 days after the scan. This will help flush the radioactive tracer from your body.
The medical staff will check the IV site for any signs of redness or swelling. Tell your healthcare provider if you see any pain, redness, or swelling at the IV site after you go home. These may be signs of infection or another type of reaction.
If you were asked to fast before the scan, you may be offered food and drink after the test. Or you may be told to have a meal.
You may go back to your usual diet and activities as directed by your healthcare provider.
Your healthcare provider may give you additional instructions, depending on your situation.
Before you agree to the test or the procedure make sure you know:
- The name of the test or procedure
- The reason you are having the test or procedure
- What results to expect and what they mean
- The risks and benefits of the test or procedure
- What the possible side effects or complications are
- When and where you are to have the test or procedure
- Who will do the test or procedure and what that person’s qualifications are
- What would happen if you did not have the test or procedure
- Any alternative tests or procedures to think about
- When and how will you get the results
- Who to call after the test or procedure if you have questions or problems
- How much will you have to pay for the test or procedure