From the Guidelines
Yes, many contrast agents used in medical imaging contain iodine. Iodinated contrast media are commonly used in CT scans, angiography, and other X-ray procedures because iodine effectively absorbs X-rays, creating clear images of blood vessels and organs. These contrast agents typically contain organically bound iodine in concentrations ranging from 150-400 mg of iodine per milliliter. Common examples include iohexol (Omnipaque), iopamidol (Isovue), and ioversol (Optiray) 1. Iodine works as an effective contrast agent because its high atomic number (53) allows it to attenuate X-rays more effectively than surrounding tissues. This property makes iodinated structures appear bright or opaque on X-ray images. It's essential to note that patients with iodine allergies or severe seafood allergies may be at higher risk for reactions to these contrast agents, and healthcare providers should be informed of such allergies before any contrast-enhanced imaging procedure is performed 1. Alternative non-iodinated contrast agents are available for patients who cannot receive iodine-based contrast. Key considerations for the use of iodinated contrast media include assessing the risk for contrast-induced acute kidney injury (CI-AKI) and using the lowest possible dose of contrast medium in patients at risk for CI-AKI 1. The use of iso-osmolar or low-osmolar iodinated contrast media is recommended in patients at increased risk of CI-AKI, rather than high-osmolar iodinated contrast media 1. Intravenous volume expansion with either isotonic sodium chloride or sodium bicarbonate solutions is also recommended in patients at increased risk for CI-AKI 1. Overall, the use of iodinated contrast media requires careful consideration of the potential risks and benefits, particularly in patients with pre-existing kidney disease or other risk factors for CI-AKI.
From the Research
Contrast Media Composition
- Contrast media used in radiology practices contain iodine, as indicated by the term "iodinated contrast agents" 2, 3, 4, 5
- Iodinated contrast media are widely used due to their low rate of adverse effects, with contrast-induced nephropathy being the most serious one 3
- The use of iodinated contrast agents is essential for providing accurate diagnoses in most radiology practices 4
Safety and Usage
- Iodinated contrast agents are safe and effective when administered correctly, but reactions can occur and be life-threatening 4
- Precautions should be taken when using iodinated contrast agents in patients with risk factors, such as impaired renal function or those treated with metformin 3
- Alternative contrast media, such as carbon dioxide, gadolinium, and dilute ICM, can be used in patients with iodinated contrast allergy or renal dysfunction 6