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Test Code IODCU Iodine/Creatinine Ratio, Random, Urine


Ordering Guidance


Due to the significant variation in the rate of secretion over the course of a day, a 24-hour collection is preferred. For more information see UIOD / Iodine, 24 Hour, 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, wait a minimum of 96 hours before starting collection.

Supplies: Urine Tubes, 10 mL (T068)

Collection Container/Tube: Clean, plastic urine collection container

Submission Container/Tube: Plastic, 10-mL urine tube or a 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

Assessment of iodine toxicity or recent iodine exposure using a random urine collection

 

Monitoring iodine excretion rate as index of replacement therapy

Profile Information

Test ID Reporting Name Available Separately Always Performed
IODC Iodine/Creat Ratio, U No Yes
CRETR Creatinine, Random, U No Yes

Method Name

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

CRETR: Enzymatic Colorimetric Assay

Reporting Name

Iodine/Creat Ratio, Random, U

Specimen Type

Urine

Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 30 days
  Frozen  30 days
  Ambient  14 days

Reject Due To

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Clinical Information

Iodine is an essential element for thyroid hormone production.

 

The measurement of urinary iodine is preferred for assessment of toxicity, recent exposure, and monitoring iodine excretion rate as an index of replacement therapy.

Reference Values

0-17 years: Not established

≥18 years: <584 mcg/g creatinine

Day(s) Performed

Tuesday, Friday

Report Available

2 to 5 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

83789

82570