Magnetic Resonance Imaging Contrast Agents, Iron-containing (Diagnostic)

Before Having This Test

In deciding to use a diagnostic test, any risks of the test must be weighed against the good it will do. This is a decision you and your doctor will make. Also, test results may be affected by other things. For MRI contrast agents, the following should be considered:

Allergies - Tell your doctor if you have ever had any unusual or allergic reaction to contrast agents or to injectable preparations of iron. Also, tell your doctor if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy - Studies with ferumoxides have not been done in pregnant women. However, in animal studies, ferumoxides caused birth defects in the offspring when given to the mother in doses many times larger than the human dose. Also, it is not yet known what effect the magnetic field used in MRI might have on the development of the fetus. Be sure you have discussed this with your doctor.

Breast-feeding - It is not known whether ferumoxides passes into the breast milk. However, your doctor may want you to stop breast-feeding for some time after you receive an MRI contrast agent. Be sure you have discussed this with your doctor.

Children - There is no specific information comparing use of MRI contrast agents in children with use in other age groups.

Older adults - Ferumoxides has been used in tests in older adults and has not been shown to cause different side effects or problems in older people than it does in younger adults.

Other medical problems - The presence of other medical problems may affect the use of MRI contrast agents. Make sure you tell your doctor if you have any other medical problems, especially:

• Allergies or asthma (history of) or
• Immunity problems - If you have a history of allergies or asthma or have a decreased natural immunity, you may be at greater risk of having an allergic reaction to the contrast agent

Preparation for This Test

Your doctor may have special instructions for you to get ready for your test, depending on the type of test you are having. If you do not understand the instructions you receive or if you have not received any instructions, check with your doctor ahead of time.