Magnetic Resonance Imaging
Conditions
Keywords
Contrast agents, Gadolinium, Recycling, MRI, Gadoteric acid
Brief summary
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
Urine samples are collected before Gd-CAs injection, and between 0- and two-and-a-half-hour post-injection of Gd-CAs.
Sponsors
Centre Hospitalier Régional Metz-Thionville
University of Lorraine
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE
Intervention model description
A single-center cohort descriptive study
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Urinary excretion of gadolinium-based contrast agents (Gd-CAs) | at 2 hours and a half after Gd-CAs injection | Describe the kinetics of urinary excretion of GdCAs during the 2H30 following gadoline contrast injection in patients undergoing injected MRI at the Mercy Hospital Medical Imaging Department. The cumulative quantity of gadolinium-based contrast agents (Gd-CAs) (mg) mesured in urine during spontaneous micturition between 0 and 2H30 after injection of gadoline contrast medium and during micturition on demand at 2.30 h. The amount of Gd present in the urine (directly associated with the presence of Gd-CAs) is determined by inductively coupled plasma mass spectrometry (ICPMS). Urine concentrations are expressed in µg/L. Taking into account the volume of urine collected, the quantity of Gd is calculated and expressed in mg. This quantity is then expressed as a percentage of the quantity of injected-Gd-CAs. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Time to first spontaneous micturition | up to 2 hours and a half after Gd-CAs injection | Duration (in minutes) between time of Gd-CAs injection and time of first spontaneous micturition. |
| Study refusal rate | Day 0 (MRI) | Percentage (%) of study refusal |
| Rate of premature study exit | at 2 hours and a half after Gd-CAs injection | Percentage (%) of premature study exit |
| Renal function | Day 0 (MRI) | Glomerular filtration rate (GFR: mL/min) estimated by the CKD-EPI method on the day of MRI. |
| Volume of beverages | at 2 hours and a half after Gd-CAs injection | Volume of beverages drunk (mL) after each micturition, declared by the patient since Gd-CAs injection, to the nearest 100 mL. |
Countries
France
Contacts
CONTACTArpiné EL NAR, PhD
CONTACTMélanie JUNKE
PRINCIPAL_INVESTIGATORRémi DUPRES, MD
CHR Metz Thionville Hopital Mercy
Outcome results
None listed