How It Is Done
A gallbladder scan is usually done by a nuclear medicine technologist. The scan pictures are usually interpreted by a radiologist or nuclear medicine specialist.
You will need to remove any jewelry that might interfere with the scan. You may need to take off all or most of your clothes, depending on which area is being examined (you may be allowed to keep on your underwear if it does not interfere with the test). You will be given a cloth or paper covering to use during the test.
During the test
The technologist cleans the site on your arm where the radioactive tracer will be injected. A small amount of the radioactive tracer is then injected.
You will lie on your back on a table and a large scanning camera will be positioned closely above your abdomen. After the radioactive tracer is injected, the camera will scan for radiation released by the tracer and produce pictures as the tracer passes through your liver and into your gallbladder and small intestine. The first pictures will be taken right after the injection. The pictures may be continuous (like a video) or may be taken once in a while for up to the next 1½ hours. Each scan takes only a few minutes. You need to lie very still during each scan to avoid blurring the pictures. The camera does not produce any radiation, so you are not exposed to any more radiation while the scan is being done.
A substance (cholecystokinin) that stimulates the gallbladder may also be injected into your vein during the scans. The pictures taken after this injection can help determine whether the gallbladder is functioning normally. Computer analysis of the data may be used to check gallbladder function. You may be asked to answer questions about your reaction to the cholecystokinin. Occasionally medicine (morphine sulfate) is given to help diagnose inflammation of the gallbladder.
The gallbladder scan takes about 1 to 2 hours.
After the test
Depending upon your results, additional scans may be taken up to a day later. If you need to return for another gallbladder scan, you should not eat any fatty foods before you return.