Magnetic Resonance Imaging Contrast Agents, Iron-containing (Diagnostic)
   
Magnetic Resonance Imaging Contrast Agents, Iron-containing (Diagnostic)
Description
Iron-containing MRI (magnetic resonance imaging) contrast agents (also called superparamagnetic agents) are used to help provide a clear picture during MRI. MRI is a special kind of diagnostic procedure. It uses magnets and computers to create images or "pictures" of certain areas inside the body. Unlike x-rays, it does not involve ionizing radiation.
Ferumoxides, an iron-containing contrast agent, is given by injection before MRI to help find and diagnose tumors of the liver.
The dose of ferumoxides will be different for different patients according to body weight.
Ferumoxides is to be used only by or under the supervision of a doctor.
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.
Along with their needed effects, MRI contrast agents may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Less common or rare
Back, leg or groin pain (severe); itching, watery eyes; skin rash or hives; swelling of face; thickening of tongue; unusual tiredness or weakness (severe); wheezing, tightness in chest, or troubled breathing.
Other side effects may occur that usually do not need medical attention. These side effects may go away as your body adjusts to this agent. However, check with your doctor if any of the following side effects continue or are bothersome:
Less common
Brown discoloration of skin; nausea; unusual warmth and flushing of skin.
Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.
October 22, 1997 
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