![]() ![]() In 2009, the FDA determined that moderate renal impairment (eGFR of 30-60) was NOT a risk factor for NSF, reversing the position it had taken in December 2006, and stated 2 “The December information was based upon reports of NSF among patients with purportedly moderate renal insufficiency. ![]() The exact etiology of NSF is unclear but most reported cases have been documented in patients with severe acute or chronic renal failure, with a glomerular filtration rate (GFR) 30 1. NSF is generally seen in the middle-aged, but has also been reported in the elderly and in children. Intravenous requirements for mr contrast agents skin#This rare but serious systemic disease is characterized by fibrosis of the skin and other tissues throughout the body. This changed in 2006 when the FDA first reported the association between nephrogenic systemic fibrosis (NSF) and intravenous gadolinium administration. Intravenous MRI contrast agent safety and Nephrogenic systemic fibrosis are discussed separately.The administration of intravenous gadolinium-containing contrast media was historically considered safe in patients with impaired renal function. Indications for use and efficacy are similar to the other agents. It is a low osmolar, nonionic contrast as is Gadodiamide. Gadoteridol (Prohance, Squibb) is the third intravenous contrast agent on the market. No abnormal serum bilirubin levels occur, however elevated serum iron levels occurred with an incidence of 8.2% in one study of 73 patients.The efficacy of this contrast is similar to that of Gd-DTPA. It has a median lethal dose of 34 mmol/kg resulting in a safety ratio of 2-3 times that of Gd-DOTA, and 3-4 times that of Gd-DTPA. Gadodiamide (Omniscan, Winthrop Pharm.) is a nonionic complex with two-fifths of the osmolality of Gd-DTPA. Ionic chelates are also hyperosmolar and some of their side effects may be attributed to this property. The development of nonionic contrast agents for MRI has paralleled that for iodinated contrast materials. It is distributed in the intravascular and extracellular fluid spaces, does not cross an intact blood-brain-barrier, and is excreted rapidly by glomerular filtration. Gd-DTPA has similar pharmacokinetics as iodinated contrast agents. This large magnetic moment is related to its seven unpaired orbital electrons. Gd has a large magnetic moment, exceeded only by Dysprosium(III) and Holmium(III), explaining its paramagnetic properties at low concentrations. Gd-DTPA was the first intravenous MR contrast agent to be approved for human use (Magnevist, Berlex Labs). Chelates with a higher stability constant have since been used successfully such as Gd-DTPA. IonicsĬhelates of paramagnetic ions Cr and Gd with EDTA were first used however EDTA was of relatively low stability resulting in toxicity in animals . With chelation of these ions, acute toxicity is reduced and elimination rate is increased thereby reducing the chance of long term toxicity. Paramagnetic metal ions suitable as MR contrast agents are all potentially toxic when injected IV at or near doses needed for clinical imaging. NOTE: This article has been transferred from and was last updated in March 5, 1996. The particulates, sequestered in the liver, spleen, and lymph nodes, the intravascular agents, confined to the blood pool, and tumor specific agents are discusses separately (see bottom). ![]() Intravenous MRI contrast agents include chelates of paramagnetic ions, both ionic and nonionic. ![]()
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