Tests That Help Evaluate Bile Duct Cancer
Your doctor took a biopsy from your bile duct to confirm that you have cancer. Your doctor may request other tests to learn more about your specific type of cancer and to pinpoint its location. This helps decide on the treatment that is likely to be most effective and appropriate for you. Imaging tests help your doctor see what’s happening inside you. These imaging tests help your doctor see the extent of the bile duct cancer. You may have one or more of these tests.
Computed tomography scan (CT Scan)
When you have bile duct cancer, CT scans also help your doctor see if the tumors have spread into lymph nodes in your abdomen or to other nearby organs. During a CT scan, X-rays scan the abdomen in about 15 to 25 seconds. A CT scan provides a better picture, making it easier to locate the tumor than with ultrasound.
To have the test, you lie still on a table as it gradually slides through the center of the CT scanner. Then the scanner directs a continuous beam of X-rays at your abdomen. A computer uses the data from the X-rays to create many pictures of your abdomen, which can be used together to create a three-dimensional picture. A CT scan is painless and noninvasive. You may be asked to hold your breath one or more times during the scan. In some cases, you may be asked to drink a contrast dye four to six hours before the scan. You may be asked not to eat anything in the time between drinking the contrast dye and having the scan. The contrast dye will gradually pass through your system and exit through your bowel movements.
Magnetic resonance imaging (MRI)
An MRI uses magnets, radio waves, and a computer to make images of tissues and organs inside your body. MRIs may also be used to help determine if cancer has spread outside of your bile ducts. Like a CT scan, an MRI can show more detail than X-rays. Overall, MRI is not clearly better than a CT scan for bile duct cancer detection. However, a new form of test, called magnetic resonance cholangiopancreatography (MRCP), is rapidly becoming popular because of its clear and detailed images of this area in the body. MR angiography (MRA) is an MRI study of the blood vessels. It gives the best picture of the blood vessels in the area. MRI may be used instead of a CT scan for people who are allergic to contrast dye.
For this test, you lie still on a table as it passes into a large steel tube that will scan your body. While inside the tube, radio waves called radiofrequency signals are sent through your body to your abdomen. These are not X-rays. They are painless and noninvasive, and will cause no harm. A computer uses the data from the radio waves to create a three-dimensional picture of the inside of your body. You may need more than one set of images. Each one may take two to 15 minutes, so the whole scan may take an hour or more. There are loud, grating, and thumping noises created during the scan. You will be given earplugs, headphones, or both to wear. If you are claustrophobic, you may be given a sedative before having this test. A two-way intercom will let you talk to the people controlling the scanner.
Positron emission tomography (PET) scan
This test measures the metabolic activity of the tissues. A radioactive material is injected into your vein. Then, a machine takes pictures of your entire body, showing the "hot spots" where the activity of the injected material is increased. This test is sometimes useful to differentiate live tumor cells from scar tissue (tumor cells will appear "hot" in the PET scan, but scar tissue is usually "cold") since scar tissue does not accumulate the material. A PET scan may be combined with a CT scan (PET-CT scan) to provide more information.