NSF risk rates vary depending on types of contrast agent
The benchmark incidence of nephrogenic systemic fibrosis (NSF) was much greater at two centers where gadodiamide was used than at the two centers where gadopentetate dimeglumine was used, according to a study published online July 15 in Radiology.

Rebecca Wertman from the school of medicine at the University of North Carolina at Chapel Hill, N.C., and colleagues retrospectively sought to determine the benchmark incidence of NSF, related to the confirmed use of different gadolinium chelate contrast agents at four U.S. university tertiary-care centers.

The researchers identified patients who had a diagnosis of NSF between January 2000 and December 2006 with renal transplant and dialysis services. The investigators confirmed the diagnosis of NSF histopathologically in all patients. They also assessed the association of NSF development with gadolinium chelate contrast agent administration in each patient.

Gadodiamide was used at University of North Carolina at Chapel Hill (center A) and Emory University in Atlanta (center B), while gadopentetate dimeglumine was used at Wake Forest University in Winston-Salem, N.C. (center C), and Thomas Jefferson University in Philadelphia (center D) during the study period, the authors wrote.

Wertman and colleagues found that patients at center A, nine patients at center B, three patients at center C and one patient at center D had NSF and had undergone gadolinium chelate–enhanced MRI.

The researchers concluded that incidence of NSF was one in 2,913 patients who underwent gadodiamide-enhanced MR exams and one in 44,224 patients who underwent gadopentetate dimeglumine–enhanced MR exams.

Of the total of 50 patients with a diagnosis of NSF at the four institutions, the investigators found that 36 had undergone gadolinium chelate–enhanced MRI at the centers only and thus constituted the final study population used to calculate the benchmark incidence of NSF. The 36 patients were aged 17–75 years (mean age, 47.1 years) and 20 were male (mean age, 49.6 years) and 16 were female (mean age, 43.9 years). In addition, 23 of these 36 patients were inpatients and 13 were outpatients, according to the researchers.

Based on their findings, the authors wrote that “in terms of MR contrast agent administration, the practice at most centers has been to shift to the use of more stable agents that are associated with a lower risk of NSF. Some centers have opted to use a dual contrast agent approach, in which the use of more stable chelates is reserved for patients at risk for NSF and the use of less stable chelates is reserved for the general population.”