Gadolinium is considered a paramagnetic metal ion, a substance that is known to move into magnetic fields. It is this property that makes Gadolinium so useful in Magnetic Resonance Imaging (MRI) and was approved for this use by the US Food and Drug Administration (FDA) in 1988. The substance is used as a contrast agent, meaning that the substance creates a clearer picture when used in conjunction with an MRI. In some cases, Gadolinium is used with Magnetic Resonance Angiography, another imaging procedure, even though it has not been approved by the FDA for this use. An MRA is an upgraded type of MRI used to study images of blood vessels. This procedure can detect heart defects, heart disease, and strokes using highly specialized imaging techniques.
An MRI or MRA can be performed without the use of a contrast agent containing Gadolinium, but many believe that MRI images that are taken using Gadolinium based contrast agent are highly superior to images taken without them. Measures are taken to ensure that the toxicity of the Gadolinium is greatly reduced and the contrast agent is eliminated from the body by the kidneys in a short period of time. Although it has been reported that the use of a Gadolinium based contrast agent can enhance the images collected from a MRA, the FDA has not yet approved any Gadolinium based contrast agent for this use. The MRA does have the ability to obtain detailed images without the use of any contrast agent.
There are no MRI contrast agents approved by the FDA that are free of Gadolinium. Any other contrast agent requires the use of an X-ray to provide detailed images of the body. These contrast agents are commonly used in CT scans, X-rays, and X-ray angiography, but are of no use when used with an MRI. There are five Gadolinium based contrast agents that are approved for use during MRI by the FDA. These approved contrast agents include Magnevist (manufactured by Bayer Healthcare Pharmaceuticals), Omniscan (manufactured by GE Healthcare), OptiMARK (manufactured by Mallinckrodt Inc.), MultiHance (manufactured by Bracco Diagnostics), and ProHance (also manufactured by Bracco Diagnostics).
Contrast agents containing Gadolinium have been linked to a rare, potentially life threatening illness that occurs in patients with kidney disease or kidney failure. The condition is called Nephrogenic Systemic Fibrosis (NSF) also known as Nephrogenic Fibrosing Dermopathy (NFD). NSF/NFD causes thickening and tightening of the skin on the body resulting in limited physical abilities and causing a great amount of pain and discomfort. The condition will also affect the connective tissues of the body, causing them to calcify and stiffen, and may spread to the individual’s internal organs, causing the failure of these organs. There is no cure available for NSF/NFD and many treatments are not effective every time with every patient. NSF/NFD is a progressive condition which can ultimately result in the death of the patient. NSF/NFD is considered a rare condition, with less than 300 confirmed cases occurring worldwide.