We have read with great interest the recent editorial by Dr. Peter Dawson entitled “Nephrogenic Systemic Fibrosis: Possible Mechanisms and Imaging Management Strategies” which appeared in the October issue of the Journal of Magnetic Resonance Imaging (1). Although the article is well written, there are shortcomings which should be brought to the attention of the readers of JMRI to prevent misconceptions and misunderstandings. Above all, Table 1 indicates that there have been cases of nephrogenic systemic fibrosis (NSF) with certain gadolinium-based contrast agents (GBCAs) only. Unfortunately, it is not clear whether Table 1 refers to cases spontaneously reported by healthcare professionals or by consumers to the healthcare authorities (“spontaneous reports”) or cases described in peer-reviewed articles. In our experience, several spontaneous reports, especially those reported by consumers, turn out not to be NSF, many are not biopsy-proven, and duplications of the same report are possible. Nevertheless, all spontaneous reports are promptly submitted to the healthcare authorities, independently of their quality or accuracy. The quality of NSF cases reported in peer-reviewed articles is usually more reliable, even if a few cases are not biopsy-proven (2). Besides, it is not clear whether Table 1 refers solely to “unconfounded” cases of NSF (ie, NSF occurring following documented administration of one GBCA alone) or “confounded” cases (ie, when patients developed NSF after undergoing MRI examinations with two or more GBCAs). In either case, Table 1 is incorrect. As for spontaneous reports, there have been confounded NSF cases with the majority of the GBCAs, the macrocyclic GBCAs Dotarem, ProHance, and Gadovist included (3-7). Most of the unconfounded cases have been reported after the administration of Omniscan, followed by Magnevist and OptiMARK. There is one unconfounded case, reported as a “mild case of nephrogenic fibrosing dermopathy,” also with the macrocyclic ProHance. As for cases reported in peer-reviewed articles, Broome (7) recently completed a thorough analysis and summary of the medical literature. According to the results of this extensive analysis, as of February 1, 2008, there were 186 biopsy-proven cases of NSF published in the peer-reviewed literature with the following unconfounded associations: 157 Omniscan, 8 Magnevist, 3 OptiMARK, and 18 unspecified GBCAs. A further four cases were confounded with more than one GBCA, while five additional cases were not associated with any GBCA. It is important to underline that it is still unclear whether GBCAs trigger NSF. Nevertheless, it is appropriate to assume for now that a potential association might exist for all GBCAs, macrocyclic agents included. Preventive measures, above all the prompt identification of patients at risk, may minimize the risk of developing NSF (4). Alberto Spinazzi MD*, Miles A. Kirchin PhD , Gianpaolo Pirovano MD*, * Worldwide Medical & Regulatory Affairs, Bracco Diagnostics Inc., Princeton, NJ, USA, Worldwide Medical & Regulatory Affairs Bracco Imaging SpA Milan, Italy.