Contrast media is administered when patients undergo examinations by X-ray (certain radiographic examinations, CT scans) or by MRI (Magnetic Resonance Imaging). Using contrast agents can help to differentiate between structures and fluids enabling better visualisation. There are other medical imaging techniques which may or may not require technique specific contrast agents.
Contrast agents are drugs that are generally administered directly into veins, arteries or joints or orally. They are used to visualize organs such as the brain, kidneys, liver, blood vessels and stomach and any abnormalities affecting them.
Contrast agents can be split into different categories, the main ones are:
For X-ray procedures
- Iodinated contrast agents (water soluble or oil based)
- Barium sulphate (for examinations of the digestive tract)
For Magnetic Resonance Imaging (MRI)
- Gadolinium based complexes
- Iron oxide nanoparticles
Contrast agents are prescription only medicines, they are administered to patients by healthcare professionals depending on the need of the examination and the imaging technique used.