Use of Contrast Media in X-Ray

Body parts look the same on an X-ray. Contrast media create a contrast between the organ your caregiver wants to see and the surrounding tissue. X-ray contrast media are a non-toxic (not harmful) solution. They contain material that shows up on x-ray. Iodine is one example of contrast media. When x-rays hit iodine, the area appears white on the X-ray film. This highlights the detail of the organ your caregiver wants to see.


There are many x-ray exams in practice today that use contrast media. A few of the most common are:

  • ANGIOGRAPHY - The x-ray procedure which looks at blood vessels is called angiography. There are 2 kinds:

  • Arteriography, means arteries are being looked at.

  • Venography, means veins are being looked at.

  • DIGITAL SUBTRACTION ANGIOGRAPHY (DSA) - Looks at vessels filled with contrast media free from overlying structures.

  • INTRAVENOUS UROGRAPHY (INTRAVENOUS PYELOGRAPHY, IVU, IVP) - Intravenous urography remains the basic x-ray examination of the urinary tract. Its main purpose is to look at the kidney shape, structure, and function. A series of x-ray taken after the injection will highlight the urinary tract. This includes the kidney, ureters, and bladder.

  • COMPUTED TOMOGRAPHY (CT) - CT look at cross-sections of organs in a patient. Most involve the use of a contrast medium. In recent years, an advanced CT technique called spiral or helical CT has become important.

  • INTERVENTIONAL TECHNIQUES - Contrast media are often required to monitor the course and success of procedures. Contrast media are used in techniques for treating:

  • The widening of narrowed arteries (angioplasty, percutaneous transluminal angioplasty, PTA).

  • Deliberate closure of arteries supplying abnormal areas such as lumps (tumors), a ballooning of a weak spot in the vessel wall (aneurysms).

  • Vascular malformations.

  • Stopping a bleeding artery.


Adverse reactions to contrast media are uncommon but do occur. Adverse reactions are usually mild to moderate. They usually last a short time. They often resolve themselves without medical treatment. Among the most frequently observed reactions to contrast media are:

  • Feeling sick to your stomach (nausea).

  • Vomiting.

  • Allergy-like symptoms.

More rare serious adverse reactions have been observed. To decrease the risk of adverse reactions, healthcare professionals ask questions about individual patient's medical history, including:

  • Are you taking any medication (prescribed or over the counter)?

  • Have you ever had a reaction to contrast media or any other substance containing iodine?

  • Do you have allergies such as hay fever, or to medications?

  • Do you have a pre-existing condition like diabetes, kidney (renal) or liver disease?

  • Are you pregnant?

  • Are you breastfeeding?


Before an examination, it may become necessary to remove some items including:

  • Dentures.

  • Jewelry.

  • Any material that may interfere with the x-ray.

Should you have any further questions, please do not hesitate to consult your caregiver.