Despite the overall excellent safety profile of gadolinium-based contrast agents (GBCAs) and long history of clinical use [ 1 Schieda N. Blaichman J.I. Costa A.F. et al. Gadolinium-based contrast agents in kidney disease: a comprehensive review and clinical practice guideline issued by the Canadian Association of Radiologists. Can J Kidney Health Dis. 2018; 69: 136-150 Google Scholar , 2 ACRManual on Contrast Media, version 9. http://www.acr.org/Quality-Safety/Resources/Contrast-ManualDate accessed: April 1, 2020 Google Scholar ], recent concerns have arisen because of recognition that gadolinium from GBCAs can be retained in humans for months to years after exposure. The clinical effects are unknown, and to date there is no scientific evidence linking gadolinium retention to adverse clinical outcomes. Nevertheless, a small number of patients have reported symptoms to health care regulatory bodies that they attribute to GBCA exposure and gadolinium retention. These self-reported symptoms vary in type and timing, with many occurring within 48 hours, but have not been substantiated or confirmed to be related to gadolinium retention [ 3 Costa A.F. van der Pol C.B. Maralani P.J. et al. Gadolinium deposition in the brain: a systematic review of existing guidelines and policy statement issued by the Canadian Association of Radiologists. Can Assoc Radiol J. 2018; 69: 373-382 Abstract Full Text Full Text PDF PubMed Scopus (41) Google Scholar , 4 McDonald R.J. Levine D. Weinreb J. et al. Gadolinium retention: a research roadmap from the 2018 NIH/ACR/RSNA Workshop on Gadolinium Chelates. Radiology. 2018; 289: 517-534 Crossref PubMed Scopus (169) Google Scholar , 5 Croteau D. Adverse events with gadolinium retention after gadolinium-based contrast agent exposure: FDA Adverse Event Reporting System and medical literature review. https://www.fda.gov/media/107662/downloadDate accessed: December 8, 2019 Google Scholar ].