Role of Contrast in MR Imaging

Abstract

Magnetic resonance (MR) contrast agents have been widely used over the last 3 decades in routine clinical practice. Paul Lauterbur recognized the presence of these contrast agents, which act as paramagnetic catalysts that accelerate the T1 relaxation process. The first MR contrast agent to be approved for clinical use was in 1988, and since then, it is estimated that 200 million doses have been administered worldwide. These contrast agents have diverse clinical as well as research applications, involving almost all the body organs. This review will cover some existing as well as many new applications that have emerged over the last few decades. MR imaging now has the potential of being used to monitor enzymatic activity, gene expression, metal ion homeostasis, and cell death in vivo. In future, newer contrast agents will develop and become commercially available, expanding the current clinical applications of MR contrast media.

Gadolinium toxicity and treatment

“…Allergic-like reactions are uncommon and vary in frequency from 0.004% to 0.7% [13]; lower than the rate of incidence for acute adverse reactions associated with low-osmolar nonionic iodinated contrast media used for CT scans, which itself is already low (0.2%) [14].…”

“…Acute adverse events (AE) can be divided according to its mechanism into immediate hypersensitivity (allergic-like) reactions Magnetic Resonance Imaging 34 (2016) [1394][1395][1396][1397][1398] (typically occur within seconds or minutes after the injection and imply an immune response to the whole or part of the GBCA) or physiologic reactions (coldness, warmth, or pain at the injection site, nausea with or without vomiting, headache, paresthesias, and dizziness). According to severity, AE can be classified into mild (self-limited with signs and symptoms showing no evidence of progression), moderate (more pronounced symptoms, such as bronchospasm, laryngeal edema, and/or generalized erythema) or severe (life threatening, including severe laryngeal edema, convulsions, profound hypotension, unresponsiveness, arrhythmia, and/or cardiopulmonary arrest) [13].…”

“…Severe life-threatening anaphylactic and fatal reactions do occur, but are exceedingly rare (0.001% to 0.01%) [13,[15][16][17], with only 40 deaths reported in 51 million GBCA doses administered between 2004 and 2009 [18]. The rarity of severe reactions makes it difficult to analyze accurately any differences between the reactions associated with individual GBCAs.…”