Oral cholecystogram

Definition

Oral cholecystogram is an x-ray of the gallbladder, an organ in the right upper abdomen that stores bile. The x-ray is taken before the gallbladder releases bile.

Alternative Names

X-ray - gallbladder; Gallbladder series; OCG; Gallbladder x-ray

How the test is performed

The test is done in a hospital radiology department or in the health care provider's office by an x-ray technician. The night before the test, you swallow six tablets (one at a time). These tablets contain a special dye (contrast medium) that helps the gallbladder show up better on the images.

At the hospital, you will lie on the x-ray table and will be asked to change position from time to time.

The health care provider may look at your gallbladder with a fluoroscope, an x-ray that can be immediately seen on a TV-like monitor. Then you may be asked to drink a high-fat liquid that will cause the gallbladder to contract and release some bile. X-ray images will be taken at timed intervals.

How to prepare for the test

Tell your doctor if you are pregnant or allergic to x-ray contrast material.

The day before the test you will be asked to eat a high-fat meal (eggs, butter, milk, or fatty meats) at noon. That evening, you should eat a low-fat meal (fruits, vegetables, bread, tea or coffee, and only lean meat).

Two hours after the low-fat meal, take the six tablets, one at a time. After taking the tablets, do not drink anything until after the test.

How the test will feel

There is little or no discomfort from the test, although you will probably be hungry and thirsty. Some people experience side effects from the contrast material. There is a slight chance of developing diarrhea.

Why the test is performed

The test is used to help diagnose disorders of the liver and gallbladder, especially gallstones. For most purposes, it has been replaced by other tests, such as abdominal ultrasound or gallbladder radionuclide scan.

What abnormal results mean

• Cholesterol polyps (noncancerous growths)
• Gallstones
• Inflammation
• Tumors

What the risks are

There is a chance of an allergic reaction to the contrast material.

There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most experts feel that the risk is low compared with the benefits. Pregnant women and children are more sensitive to the risks of x-rays.

Special considerations

Ultrasound and MRI examination of the gallbladder has largely replaced the use of oral cholecystogram, especially in patients with diseased livers. Another type of scan (a nuclear medicine HIDA scan) may be used to see how the gallbladder works.

References

Afdahl NH. Diseases of the gall bladder and bile ducts. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 159.