What Is a Cholecystogram?

A cholecystogram is a medical imaging study of the gallbladder a doctor may order to identify stones. Stones can interfere with gallbladder function and may cause medical complications for the patient. A doctor may request this test if she believes a patient has stones and wants to determine how severe they are and what kind of treatment would be more appropriate. The test requires some preparation, and patients need to follow directions carefully.

In a cholecystogram, a contrast agent will highlight any stones present in the gallbladder. The patient usually needs to eat a low fat diet on the day preceding the test to concentrate bile in the gallbladder. He may receive some tablets of contrast agent to take the night before the test. In other facilities, a care provider will inject the contrast agent intravenously on the day of the test and give it some time to circulate and build up in the gallbladder.

The patient consumes a high fat beverage or food to trigger the release of bile while a radiologist examines the gallbladder with fluoroscopy. The x-ray images will show the movement of bile and any stones, made more visible with the use of the contrast agent. A cholecystogram can catch stones of varying sizes and identifies them accurately in more than 90% of cases. With the outcome of the test, the doctor can determine if the patient needs surgery or other treatments.

The cholecystogram procedure is relatively low risk. Some patients have iodine allergies and may not be able to take the contrast agent. The x-ray radiation also poses a potential risk, but a relatively low one. Unless a patient has a lot of x-rays for other reasons, or does not receive proper shielding in the x-ray suite, the risks should be much lower than the benefits of the test. Some patients may find the dietary recommendations before the test difficult, but they only last for a day, and a doctor or nutritionist may have some meal tips to help the patient prepare.

One alternative to a cholecystogram is an ultrasound of the gallbladder. The advantage to this procedure is that the doctor does not have to wait. The patient does not need to eat low fat foods for a day and take the contrast agent before an ultrasound, and thus a doctor can perform an immediate evaluation on a patient with a suspected case of gallstones. This procedure may be preferable for patients who cannot take iodine or who would be at risk from x-rays, such as pregnant women.