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HelpTest ID ICRU Iodine/Creatinine Ratio, Random, Urine
Useful For
Monitoring iodine excretion rate as an index of daily iodine replacement therapy
Correlating total body iodine load with (131)I uptake studies in assessing thyroid function
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| ICR | Iodine/Creat Ratio, U | No | Yes |
| CDCR | Creatinine Conc | No | Yes |
Special Instructions
Method Name
ICR: Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)
CDCR: Enzymatic Colorimetric Assay
Reporting Name
Iodine/Creat Ratio, Random, USpecimen Type
UrineCollection Container/Tube: Clean, plastic urine collection container
Submission Container/Tube: Plastic, 10-mL urine tube (Supply T068) or a clean, plastic aliquot container with no metal cap or glued insert
Specimen Volume: 2 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
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Urine | Refrigerated (preferred) | 30 days |
| Ambient | 30 days | |
| Frozen | 30 days |
Clinical Information
Iodine is an essential element for thyroid hormone production.
The measurement of urinary iodine serves as an index of adequate dietary iodine intake.
Reference Values
16-40 years: 70-530 mcg/g Creatinine
41-70 years: 70-860 mcg/g Creatinine
>70 years: 70-1,150 mcg/g Creatinine
Reference values have not been established for patients that are <16 years of age.
Cautions
Administration of iodine-based contrast media and drugs containing iodine, such as amiodarone, will yield elevated results.
Day(s) Performed
Monday, Tuesday, Wednesday, Friday; 5 p.m.
Report Available
1 dayPerforming Laboratory
Mayo Medical Laboratories in Rochester
Test Classification
See Individual Test IDsCPT Code Information
83018