Efficacy, Education, Administration, InformaticsE2707. Gadolinium Chelates: Can We Relax?
Chalian M, DiCamillo P, Shvarts M, Mansoori B, Wolansky L. University Hospitals Case Medical Center, Cleveland, OH
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Background Information: Gadolinium-based contrast agents (GBCAs) have been considered safe in current practice when used at clinically recommended doses in patients with appropriate renal function. The relationship between GBCAs and nephrogenic systemic fibrosis (NSF) in patients with renal insufficiency has resulted in new policies in contrast administration, which has largely eliminated NSF since 2009. Deposition of GBCAs in bone tissue is well established. However, increasing evidence regarding this in brain has brought new concerns regarding the safety of these agents. The purpose of this exhibit was to review basic concepts on clinically available GBCAs with the main focus on chemical models, physiochemical properties, toxicity issues including the effect of contrast dosage on brain deposition, and strategies to reduce complications related to administration of GBCAs.
Educational Goals/Teaching Points: Our aim is to provide familiarity with GBCAs available in the United States and their key properties; describe how gadolinium’s physical properties are harnessed to affect MR signal and allow contrast imaging; and note clinically relevant differences among different GBCAs. Participants will learn the known untoward effects of the GBCAs and discuss the effect of gadolinium contrast dosage on image characteristics and brain deposition.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques: This exhibit will review MR relaxivity properties of gadolinium, paramagnetic effect, MR appearance at low concentration, and MR appearance at high concentration. We show preparations available in the United States; molecular structures of chelates (linear standard relaxivity, linear high relaxivity, and macrocyclic standard relaxivity); ionicity (ionic, nonionic); differences in tissue affinity and accumulation (nonspecific extracellular, tissue-specific intracellular, intravascular);and other chemical properties of note. We also present relationship of structure to function and differences in clinical use profiles; lower dose applications; higher dose applications; hepatobiliary; blood pool binding; and untoward effects such as allergic events, physiologic events, nephrogenic systemic fibrosis, brain parenchymal staining (dentate nucleus, globus pallidus, other findings); from dose to deposition.
Conclusion: In an era of ever-increasing concerns about application of GBCAs, radiologists’ familiarity with chemical properties and pharmacokinetics of available GBCAs is of utmost importance. This will help in choosing a contrast agent to provide high-quality images, better addressing specific clinical questions, reducing rate of unexpected reactions, addressing patients’ concerns regarding the safety of contrast agents, and therefore provide optimal patient care.