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TEST ID IODCU Iodine/Creatinine Ratio, Random, Urine

Reporting Name

Iodine/Creat Ratio, Random, U

Specimen Type

Urine


Ordering Guidance


Due to the significant variation in the rate of excretion 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 potentially interfere with inductively coupled plasma mass spectrometry-based 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 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.


Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Refrigerated (preferred) 28 days
  Frozen  28 days
  Ambient  14 days

Method Name

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

CRETR: Enzymatic Colorimetric Assay

Reject Due To

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

Reference Values

0-17 years: Not established

≥18 years: <584 mcg/g creatinine

Day(s) Performed

Monday through Friday

Report Available

2 to 4 days

Specimen Retention Time

14 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

83789

82570

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

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.