A rare but serious adverse reaction has been observed in patients who received gadolinium (Gd) based contrast agents during MRI examinations, a reaction called nephrogenic systemic fibrosis (NSF). Patients with kidney disease are at increased risk of developing NSF. NSF may cause skin thickening, joint pain and/or swelling. In rare cases NSF can lead to lung and heart problems and cause death. Because of this potentially serious risk to some research participants, the Duke University Health System Institutional Review Board (DUHS IRB) requires additional safeguards when the use of gadolinium based contrast agents in research is planned.