What Nephrologists Need to Know About Gadolinium

Summary and Introduction

Summary

Gadolinium chelates are commonly used to improve tissue contrast in MRI. Until recently the use of gadolinium was thought to be risk-free compared with alternative contrast agents. Recent studies, however, have raised serious concerns regarding the safety of gadolinium chelates. Although safe in patients with normal kidney function, administration of these agents in people with renal dysfunction can result in up to three clinical problems that the nephrologist should be familiar with. The first is nephrogenic systemic fibrosis (NSF), which was initially observed in 1997. Although manifesting primarily in skin, NSF can also cause systemic fibrosis, leading to disabling contractures and even death. Gadodiamide is the agent that has been most frequently associated with NSF, but other chelates might also pose a risk. The second clinical problem is that gadolinium chelates cause acute kidney injury, especially at high doses required for angiography. The third problem is that several laboratory artifacts are associated with gadolinium administration, with pseudohypocalcemia being the most important. The risk of a patient experiencing all three of these complications increases as renal function declines. In light of these problems, nephrologists need to re-evaluate the risks and benefits of gadolinium administration in patients with chronic kidney disease stage 3 or greater, as well as in those with acute kidney injury.

Introduction

MRI has become an essential part of current medical practice on the basis of the high quality of the images the method is able to produce. Vascular enhancement with a gadolinium-based contrast agent further improves the results of MRI. Clinical trials and extensive clinical experience have proven that gadolinium-based contrast agents are safe in patients with normal kidney function. As renal function deteriorates, however, the safety of these agents diminishes. Nephrogenic systemic fibrosis (NSF) is associated with gadolinium chelates and occurs exclusively in patients with decreased renal function. The nephrotoxicity of these agents also becomes more pronounced as renal function declines. Derangement of laboratory measurements as a result of administration of gadolinium chelates is observed in patients with normal renal function, but the effect is greater and its duration longer in patients with renal insufficiency. This Review discusses the adverse effects of gadolinium-based contrast agents in patients with decreased renal function.