Gallbladder X Rays Health Article

Definition

Gallbladder x rays are diagnostic studies of the gallbladder (GB), a small pear-shaped sac that stores bile and is located under the liver. The study involves taking tablets containing iodine compounds a day before the x ray. The tablets are absorbed by the intestine, excreted by the liver and then concentrated in the gallbladder. In some clinics and hospitals the tablets are taken over a two day period, in hope of a better visualization of the gallbladder. This is known as a double-dose oral cholecystogram. This test was once the standard for diagnosing diseases of the GB; however, in recent years it is not often requested due to the advances in diagnostic ultrasound.

Purpose

This test, also known as an oral cholecystogram or OCG, is usually ordered to help physicians diagnose disorders of the gallbladder, such as gallstones, inflammation, and tumors. The test is usually ordered when a gallbladder ultrasound has proved non-diagnostic. It is used in the investigation of patients complaining of upper abdominal pain after eating a fatty meal. Obese women over forty with a diet high in fat and low in fiber are at risk for gallstones. This test also measures gallbladder function, since the failure of the organ to visualize can signify a non-functioning or diseased gallbladder. The gallbladder may also not visualize if the bilirubin level is over four, and the study should not be performed under these circumstances. A CT scan, MRI (magnetic resonance imaging), or an ERCP (endoscopic retrograde cholangio-pancreatography) would be done instead.

Precautions

The physician must be notified if the patient is pregnant or allergic to iodine. Patients with a history of severe

kidney damage have an increased risk of side effects from this procedure. Ultrasound is commonly used instead of the x-ray examination when gallstones are suspected. Some people experience side effects from the contrast material (iodine tablets), especially diarrhea. During preparation for the test, patients should not use any laxatives. Diabetics should discuss the need for any adjustment in medication with their physician.

Description

The exam is performed in the radiology department. The iodine tablets are purchased at a pharmacy or supplied by the hospital. The night before the test, patients swallow six tablets (one at a time) with plenty of water. If a double-dose OCG is requested, this will be done over a two day period.

The patient will be asked to put on a hospital gown. The x-ray technologist will take a preliminary or scout film to see if the gallbladder is well visualized. The patient is placed prone with the right side slightly raised to prevent superimposition of the spine. The first film should show all of the right side of the abdomen, from the lateral side of the spine down to the iliac crest (top of the pelvis). Tall thin patients will need to be turned more since the gallbladder tends to lie lower and closer to the spine than in shorter, heavier patients. If the gallbladder is well seen on the first film, the x-ray technologist or radiologist will take another film coned-down and centered directly on the gallbladder. At least one more film in an upright or a lateral decubitus position will be done, since gallstones tend to sink downward or float in the gallbladder, as compared to a tumor or polyp, which remains in the same position. The gallbladder can displace to a considerably lower position when the patient is upright, so the radiography technologist must take into account the bodily habitus (size and shape) of each individual patient.

The radiologist will review the x-rays and then take a series of coned-down (spot) films of the gallbladder with a fluoroscope (a special apparatus that projects the image onto a video monitor to be seen immediately). The radiologist may ask for another film to be taken 30 minutes after a fatty meal. The patient will be given a glass of egg nog or in some instances buttered toast and coffee or tea with cream. This meal will cause the gallbladder to contract and release bile, so the gallbladder should diminish in size on the post-fatty meal film (PFM). Delayed films may be taken if this doesn't occur. The exam usually takes one hour to complete and may be done in a hospital or a clinic that is certified to take x rays.