If you’re having problems with your gallbladder, your doctor may want you to have a special test called a hepatobiliary iminodiacetic acid (HIDA) scan.
During the procedure, a technician injects a tiny amount of a radioactive compound into your bloodstream. As it travels through your liver, gallbladder, and small intestine, a camera tracks its movement and takes pictures of those organs.
Why Do I Need It?
Your gallbladder is a small organ in the upper right part of your belly. It stores bile, a fluid that your liver makes to break down fats and help with digestion.
A HIDA scan checks to make sure bile is moving through your body in a normal way. It can also look for:
- Bile leakage
- Cholecystitis (an inflamed gallbladder)
- Blocked bile ducts
- Congenital bile duct defects (problems you were born with)
Preparing for the Scan
Your doctor will help you understand how to get ready for your procedure. In general, you should:
Stop certain medicines. Tell your doctor ahead of time about any medications you take on a daily basis. Some medicines keep a HIDA scan from working well. If so, your doctor will ask you to hold off on taking them until your scan is over.
Fast. You’ll need to avoid eating for at least 4 hours before your test. You may be able to drink clear liquids.
Follow your doctor’s orders. He may prescribe a special medicine that’ll help the HIDA scan get better images of your organs. You may need to start taking it a few days before your scan. Or a technician might give it to you right before your test begins.
How Does the Test Work?
You’ll lie down on an imaging table. A technician will give you a special radioactive chemical through a vein in your arm. It shouldn’t hurt, but it may feel cold. You might also feel a little pressure as the chemical enters your bloodstream.
Next, the technician will place a special camera over your belly. As the chemical “traces” the path that bile takes in your body, the camera will take certain images along the way. This process can take between 1 and 4 hours. You’ll need to stay still during this time. If not, the pictures of your gallbladder will be blurry, and you’ll have to do the scan again.
You might also receive other medicines during the test to help the technician get better images of your gallbladder. Morphine is sometimes used. If so, you may feel very sleepy for a few hours.
After your HIDA scan, you shouldn’t need a lot of time to recover. Most people go on to have a normal day. Over the next 24 to 48 hours, you’ll pee and poop out the radioactive chemical. Drink plenty of water to help remove it from your body faster.
You should get these the same day you have the scan.
If the results show that your scan was “normal,” your gallbladder is working like it should and is an average size and shape. A normal test result also means that your liver and small intestine are healthy.
If your scan was “abnormal,” it likely means your images revealed one of the following:
- An infection
- Bile duct blockage
- A problem with how your gallbladder functions
- An abnormal growth
Your doctor will want to repeat the HIDA scan or have you take another type of imaging test.
HIDA Scan Risks
The chemical you’re given is only radioactive for a few hours. After that, it’s harmless. The camera that’s used to take pictures of your organs doesn’t give off any radiation.
Doctors believe a HIDA scan is safe, but there’s a small chance of side effects. These include a rash or bruising at the site of the chemical injection. You could also have an allergic reaction to this chemical or the other medications you received during the scan.
If you have questions about an upcoming HIDA scan, be sure to talk to your doctor.