Kinetics of Urinary Excretion of Gadolinium Contrast Agents Used in MRI Examinations
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: biological samples collection.
- Who it may be relevant to
- Registry conditions: Magnetic Resonance Imaging. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- France
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Overview
This is a single-center cohort study aimed to describe the urinary excretion kinetics of gadolinium contrast agents (Gd-CAs). Patients with a prescription for injected MRI are invited to participate in the study. If they agree, blood and urine samples are collected before Gd-CAs injection, and urine samples are collected between 0- and two-and-a-half-hours post-injection of Gd-CAs.
Detailed description
The contrast agents used in MRI to characterize certain lesions contain a chemical element from the rare earth family: Gadolinium (Gd). Gd, in its isolated form, is toxic in humans, but it can still be used in the form of complex molecules such as gadolinium contrast agents (Gd-CAs), which retain its contrast power while greatly minimizing its toxicity.
The MRI is performed rapidly after the injection of Gd-CAs, and these compounds are eliminated by the urinary route in the first urine following the examination. After elimination, and in view of their very high stability, these compounds follow the path of wastewater via sewage treatment plants. However, the processes currently used in these plants do not retain them, and they remain present in the purified water discharged into rivers.
Work carried out at the Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC) at the University of Lorraine has demonstrated the bioaccumulation of these compounds in freshwater organisms. Gd-CAs then follow the classic pathway of continental waters. It should be noted that the quantity of Gd released as a result of MRI activities has been estimated on average at 1 injection per 1 g of Gd used.
In order to prevent future environmental disorders, recovery of all or part of the Gd-CAs immediately after MRI by urine collection is undoubtedly the most effective approach.
The aim of this project is to assess the feasibility of such an approach, and to propose a protocol applicable to MRI involving the injection of gadolinium contrast agents for urine collection.
This project is part of the "Rare Earths" theme of LabEx R21. It will examine the possibility of recycling gadolinium as an element or as Gd-CAs.
Interventions
- Other biological samples collection
Urine samples are collected before Gd-CAs injection, and between 0- and two-and-a-half-hour post-injection of Gd-CAs.
Primary outcome measures
- Urinary excretion of gadolinium-based contrast agents (Gd-CAs) [Time frame: at 2 hours and a half after Gd-CAs injection]
Secondary outcome measures (5)
- Renal function [Time frame: Day 0 (MRI)]
- Volume of beverages [Time frame: at 2 hours and a half after Gd-CAs injection]
- Time to first spontaneous micturition [Time frame: up to 2 hours and a half after Gd-CAs injection]
- Study refusal rate [Time frame: Day 0 (MRI)]
- Rate of premature study exit [Time frame: at 2 hours and a half after Gd-CAs injection]
Eligibility criteria
Inclusion criteria
Patients:
- over 18 years of age
- with a prescription for MRI with gadolinium-based contrast agents (Gd-CAs) injection validated by a radiologist
- affiliated with a health insurance plan
- have signed an informed consent form
Exclusion criteria
- Patients:
- with known allergy to gadolinium-based contrast agents (Gd-CAs)
- with known severe renal impairment (GFR < 30 mL/min)
- on dialysis
- with urinary incontinence
- with an ongoing urinary tract infection
- under hydric or hydrosodic restriction
- unable to urinate independently
- Protected persons (under guardianship, curatorship or safeguard of justice)
- Pregnant or breast-feeding women
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- N/A
- Model
- Single group
- Masking
- Open label
- Primary purpose
- Other
Study locations
France · 2 centers
- CHR Metz-Thionville/Hopital de Mercy — Metz
- CHR Metz-Thionville / Hopital Bel Air — Thionville
Identifiers
NCT: NCT06191731 · 2023-02-CHRMT