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Contrast Materials, Contrast Agents, and Contrast Media

Alabama Coastal Radiology Answers Your Questions about Contrast

No matter what you call it, contrast is used by radiologists to help them better identify and understand internal structures. Different substances may be used to create a contrast dye, which shows up clearly on diagnostic imaging tests such as an MRI or CT scan.

Once your physician has an improved sense of what is happening inside the body, they are better able to treat any troublesome conditions.

What is Contrast Made of?

As mentioned, there are various types of contrast that may be administered prior to a diagnostic procedure. Iodine is used in most cases, but depending upon the type of test being conducted or the patient’s allergies to a particular substance, other suitable solutions can be used, such as:

  • Barium sulfate
  • Gadolinium
  • Saline
  • Air (microbubbles)

Iodine and barium sulfate based contrast materials are typically best for an X-ray or CT scan while gadolinium is ideal for MRIs, and saline or air works well for diagnostic examinations of the heart.

How Do You Administer a Contrast Agent?

In addition to having multiple compounds to make the contrast, you also have several choices when it comes to how the contrast enters the body. Once again, these methods will differ based upon the particular type of test being done.

  • Most contrasts will be injected into the patient’s bloodstream via the veins. This is known as the intravenous method, and is often used to enhance images of the internal organs, GI tract, arteries, soft tissues, brain, and breast.
  • Contrast materials can also be given orally, allowing the patient to swallow the substance. As you can imagine, the oral method is best to examine the esophagus, pharynx, stomach, or upper gastrointestinal tract.
  • If your physician is more interested in assessing your lower gastrointestinal tract, they may recommend a rectally administered contrast by way of an enema.

Are There Risks Associated with Contrast Materials?

All types of contrast are extremely safe to use, and will be naturally expelled from the body over a short period of time. It is possible for patients to experience a reaction to their contrast agent, though severe complications are very rare.

The best way to avoid any potential problems with a contrast media is to tell your doctor about any existing medical conditions or allergies that you’re aware of.