Test Code GDUCR Gadolinium/Creatinine Ratio, Random, Urine
Specimen Required
Patient Preparation: High concentrations of gadolinium and iodine are known to interfere with most metal tests. If either gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.
Supplies: Urine Tubes, 10 mL (T068)
Collection Container/Tube: Clean, plastic urine collection container
Submission Container/Tube: Plastic, 10-mL urine tube or clean, plastic aliquot container with no metal cap or glued insert
Specimen Volume: 3 mL
Collection Instructions:
1. Collect a random urine specimen.
2. See Metals Analysis Specimen Collection and Transport for complete instructions.
Useful For
Assessing chronic exposure and monitoring effectiveness of dialysis in a random urine collection
Profile Information
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
GDCU | Gadolinium/Creat Ratio, U | No | Yes |
CRETR | Creatinine, Random, U | No | Yes |
Special Instructions
Method Name
GDCU: Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)
CRETR: Enzymatic Colorimetric Assay
Reporting Name
Gadolinium/Creat Ratio, Random, USpecimen Type
UrineSpecimen Minimum Volume
1.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Urine | Refrigerated (preferred) | 28 days | |
Frozen | 28 days | ||
Ambient | 14 days |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
0-17 years: Not established
≥18 years: <0.8 mcg/g creatinine
Interpretation
Although much of the gadolinium associated with the administration of gadolinium-based contrast agents (GBCA) is cleared in the urine in the first 96 hours, lower concentrations of gadolinium may persist in the urine for months after GBCA exposure. Elevated urine gadolinium results collected after administration of a GBCA confirm past exposure, prolonged elimination of gadolinium, and/or continued exposure through anthropogenic sources. Gadolinium also has been shown to be present in some municipal water sources, which may contribute to the observation of low concentrations of gadolinium in patients who never have been exposed to GBCA.
Elevated gadolinium in a specimen collected more than 96 hours after contrast media infusion does not indicate risk of nephrogenic systemic fibrosis.
Day(s) Performed
Thursday
Report Available
2 to 8 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterCPT Code Information
83018
82570
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
GDUCR | Gadolinium/Creat Ratio, Random, U | 93854-8 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
CRETR | Creatinine, Random, U | 2161-8 |
615339 | Gadolinium/Creat Ratio, U | 93854-8 |
Forms
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.