Nephrogenic systemic fibrosis (NSF) is a painful and debilitating fibrosing disorder of the skin and systemic tissues. It is associated with exposure to Gd, used in MRIs and MRAs, in patients with renal insufficiency. We here present an illustrative example of a young patient who underwent multiple Gd-enhanced scans, both before and after developing severe NSF. We examined biopsy tissues for quantification of detectable insoluble Gd deposits using automated scanning electron microscopy/energy dispersive X-ray spectroscopy. High concentrations of Gd associated with calcium and phosphorus in skin persisted even 3 years after the last exposure to Gd. Such long-term retention of Gd raises further concerns about the utility and safety of Gd-based contrast agents. Residual Gd chelates, after initial and rapid renal clearance, can dissociate into insoluble, toxic Gd(3+) that precipitates with tissue anions. Bone serves as a site for Gd storage. Subsequent clearance and mobilization from such stores may explain the variable latency of onset of NSF. We hypothesize that long-term persistence and slow release of Gd(3+) from bone stores can be a cause for concern of Gd-associated toxicity with long latency.
Copyright 2007 John Wiley & Sons, Ltd.