Urinary Gadolinium Levels After Contrast-Enhanced MRI in Individuals with Normal Renal Function: a Pilot Study

Abstract

Introduction Gadolinium-based contrast agents (GBCA) have been used to enhance magnetic resonance imaging (MRI) since 1985. Recently, the media and online groups have voiced concerns about gadolinium deposition in patients with normal renal function based on Belevated^urinary gadolinium levels. The determination of increased urinary gadolinium levels is based on reference ranges developed in individuals with normal renal function who were never exposed to GBCA. Studies suggest an elevated gadolinium urinary elimination greater than 72 h post GBCA scan. We evaluated urine gadolinium concentrations over a 30-day period in patients administered GBCA. Methods In this prospective, observational pilot study, we enrolled subjects between 18 and 65 years of age with normal renal function who received GBCA for the first time. Urinary gadolinium was measured at days zero (prior to GBCA exposure), 3, 10, and 30 after GBCA exposure. We compared urinary gadolinium levels after GBCA exposure to the current reference range and calculated an estimated duration of Belevated^gadolinium urine levels in the average patient. Results All 13 subjects had 24-h urinary gadolinium levels higher than 0.7 μg/24 h with means of 1944 (± 1432) μg/24 h on day 3, 301 (± 218) μg/24 h on day 10, and 34 (± 33) μg/24 h on day 30. Based on calculated urinary gadolinium elimination kinetics, we estimate urinary gadolinium levels will often remain above the current reference range for > 50 days. Conclusion The current reference range of 0.7 μg/24 h for 24 h urinary gadolinium is not applicable to patients for at least 30 days following GBCA exposure.

Altered Plasma Mitochondrial Metabolites in Persistently Symptomatic Individuals after a GBCA-Assisted MRI

“…The lifetime number of GBCA-assisted MRIs varied (1, n = 8; 2, n = 3; 3, n = 1; 4, n = 1; ≥9, n = 2). Consistent with recent evidence that GBCA excretion rates may be significantly lower than originally estimated in individuals with apparently normal renal function [27], patient urinary Gd at 1-7 months post-MRI ranged from 1.0 µg to 33.0 µg, well above clinical laboratory thresholds for unexposed individuals. Time from initial symptom-attributed MRI was only moderately negatively associated with urine Gd (log-log R 2 = −0.478; p = 0.0043), suggesting additional influences on excretion may be present.…”

Gadolinium Deposition Disease: A Case Report and the Prevalence of Enhanced MRI Procedures Within the Veterans Health Administration

“…Renal elimination (K P0 ) of Gd is intermediate (> 54 d), and long-term (ie, years) in patients (regardless of renal function). 10,11,26 Some Gdbased contrast agent may remain intact in the tissues years after exposure (similar to a "forever" chemical, harbored intracellularly with ill-defined effects on normal physiology). 46 Some Gd is dechelated from the proprietary pharmaceutical and likely rapidly complexes into compounds that comprise the nanostructures found in patients and in our models.…”

“…Nonetheless, Gd is retained long-term in subjects with normal renal function, in symptomatic patients, permanently in the brains of patients, and in every organ we have tested with our animal models. 3,7,8,[10][11][12] Patients with normal renal function continue to report symptoms attributed to Gdbased contrast agents concomitant with retarded elimination. Numerous patients with normal renal function developed similar or novel symptoms that have been attributed to Gd concomitant with detectable urinary Gd years after exposure.…”

“…7,8,42 Prolonged elimination of Gd after MRI contrast administration (months to years) may be universal. 10 Gd compartmentalizes into leukocytes and erythrocytes and into the cerebrospinal fluid within minutes. 37,43 Patients with multisymptomatic illnesses attributed to Gd (Gd deposition disease) have perturbations in cytokine levels, many inflammatory.…”

Gadolinium-based contrast agents: A clinically significant analytical interference in inductively coupled plasma mass spectrometry elemental analysis

“…Previous work has shown that urine samples from patients with normal renal function and collected three days after administration of GBCAs contained on average 1944 μ g of gadolinium per 24 h collection. 16 Furthermore, our laboratory has received patient samples with gadolinium concentrations >160,000 ppb. As a result, the laboratory needs additional safeguards other than ordering instructions to prevent samples with elevated concentrations of gadolinium from being analysed and inaccurate results being reported.…”