Cholangiography: what it is, what it is for and how it is done

Cholangiography is an X-ray exam that serves to evaluate the bile ducts, and allows the bile to be seen from the liver to the duodenum.

This type of exam is often done during bile duct surgery to remove a gallstone, for example, but it can also be recommended by the doctor to help diagnose other problems related to the bile ducts, such as:

• Obstruction of the bile ducts;
• Injuries, strictures or dilation of the ducts;
• Tumor in the bladder.

Furthermore, if an obstruction of the bile ducts is found, the doctor can, during the examination, remove what is causing the obstruction, causing an almost immediate improvement in symptoms.

How the exam is carried out

There are several types of cholangiography that can be requested according to the doctor’s suspicions. Depending on the type, the way to take the exam may be slightly different:

1. Intravenous cholangiography

This method consists of administering a contrast agent into the bloodstream, which will then be eliminated through the bile. After this, images are obtained every 30 minutes, which will allow the contrast path along the bile ducts to be studied.

2. Endoscopic cholangiography

In this technique, a probe is introduced from the mouth to the duodenum, where the contrast product is administered and then an X-ray is taken at the contrast site.

3. Intraoperative cholangiography

In this method, the examination is performed during surgery to remove the gallbladder, called cholecystectomy, in which a contrast product is administered and several X-rays are taken.

4. Magnetic resonance cholangiography

This technique is performed after gallbladder removal surgery, with the aim of evaluating the bile ducts after removal, in order to identify possible complications that may be caused by residual stones not detected during surgery.

How to prepare for the exam

Preparation for cholangiography may vary depending on the type of exam, however, general care includes:

• Fast for 6 to 12 hours;
• Drink only small sips of water up to 2 hours before the exam;
• Inform the doctor about the use of medications, especially aspirin, clopidogrel or warfarin.

In some cases, the doctor may also order a blood test up to 2 days before the test.

Possible side effects

Although it is not very common, there are some side effects that may occur due to this exam, such as damage to the bile ducts, pancreatitis, internal bleeding or infection.

After cholangiography, if symptoms such as fever above 38.5ºC or abdominal pain that does not improve appear, it is advisable to go to the hospital.

When the exam should not be done

Although this test is considered safe, it is not recommended for people who are hypersensitive to contrast, have a biliary system infection or who have high levels of creatinine or urea. In these cases, the doctor may recommend another test to evaluate the bile ducts.