What is nephrogenic systemic fibrosis (NSF), and who is at risk for developing this complication?
NSF is a rare systemic fibrotic disorder that primarily involves the skin and subcutaneous tissues, but it can also affect other organs including the lungs, pleura, pericardium, skeletal muscle, and internal organs. It occurs in patients with severe acute or chronic renal dysfunction, including patients who are receiving dialysis of any form, and in many cases is believed to be secondary to the release of free gadolinium (Gd 3+ ) ions from the chelates that constitute gadolinium-based contrast agents, with subsequent deposition of insoluble gadolinium phosphate precipitates in bodily tissues. As the contrast agents are metabolized through the renal system, they have a prolonged half-life in patients with decreased renal function, increasing the likelihood that gadolinium release and deposition in tissues will occur. However, NSF can occur without exposure to gadolinium-based contrast agents.
When NSF is associated with gadolinium-based contrast agents, it usually manifests within 2 to 10 weeks following contrast administration. The risk of NSF may be related to the specific type of contrast agent, the cumulative dose, and the residual renal function of the patient. Macrocyclic gadolinium-based contrast agents are the most stable ones and are associated with the lowest risk of NSF, followed by linear ionic and linear nonionic agents in order of decreasing stability and associated increased risk of NSF.
NSF has a high morbidity and mortality rate and has no known uniformly effective treatment. Therefore, patients who are planning to undergo MRI with gadolinium-based contrast agents must be carefully screened for renal dysfunction. When the estimated glomerular filtration rate (eGFR) is ≥ 60 mL/min/1.73m 2 , gadolinium-based contrast material can be administered as indicated, assuming there are no other contraindications. When the eGFR is 30 to 59 mL/min/1.73m 2 , a macrocyclic gadolinium-based contrast material can be administered using the lowest possible dose. When the eGFR is <30 mL/min/1.73m 2 , gadolinium-based contrast material is generally not administered unless there is an urgent medical necessity.