Sign in →

Test Code GDCRU Gadolinium/Creatinine Ratio, Random, Urine

Reporting Name

Gadolinium/Creat Ratio, Random, U

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
GDCR Gadolinium/Creat Ratio, U No Yes
CDCR Creatinine Conc No Yes

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type


Specimen Required

Patient Preparation: High concentrations of gadolinium and iodine are known to interfere with most metals 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 (T068) 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 Trace Metals Analysis Specimen Collection and Transport in Special Instructions for complete instructions.

Specimen Minimum Volume

0.7 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Refrigerated (preferred) 28 days
  Ambient  28 days
  Frozen  28 days

Reference Values

0-17 years: not established

≥18 years: <0.8 mcg/g creatinine

Day(s) and Time(s) Performed

Wednesday; 8 a.m.

Test Classification

See Individual Test IDs

CPT Code Information

83018-Gadolinium Concentration

82570-Creatinine Concentration

LOINC Code Information

Test ID Test Order Name Order LOINC Value
GDCRU Gadolinium/Creat Ratio, Random, U In Process


Result ID Test Result Name Result LOINC Value
CDCR Creatinine Conc 2161-8
32873 Gadolinium/Creat Ratio, U Unable to Verify

Clinical Information

Gadolinium is a member of the lanthanide series of the periodic table of elements and is considered a nonessential element. Due to its paramagnetic properties, chelated gadolinium is commonly employed as contrast media (gadolinium-based contrast agents: GBCA) for magnetic resonance imaging and computer tomography scanning.


Gadolinium is primarily eliminated via the kidneys, so exposure can be prolonged in patients with renal insufficiency. In healthy subjects with normal renal function, the plasma half-life of gadolinium is approximately 90 minutes (1.5 hours). Patients with reduced renal function and some patients with normal renal function may exhibit a prolonged gadolinium elimination half-life.


To date, the only known adverse health effect related to gadolinium retention is a rare condition called nephrogenic systemic fibrosis (NSF). NSF is a relatively uncommon condition in which fibrous plaques develop in the dermis and, often, in deeper connective tissues. Reported cases have occurred almost exclusively in patients with severe renal disease, and almost all have been associated with prior use of GBCA. NSF is a painful skin disease characterized by thickening of the skin, which can involve the joints and cause significant limitation of motion within weeks to months. Over the past decade, changes in clinical practice guidelines have almost completely eliminated the incidence of NSF. However, the association of NSF and observed elevated gadolinium concentrations is still not fully understood.

Analytic Time

1 day

NY State Approved


Method Name

GDCR: Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

CDCR: Enzymatic Colorimetric Assay