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Test Code GDU Gadolinium, 24 Hour, Urine

Performing Laboratory

Mayo Medical Laboratories in Rochester

Reporting Name

Gadolinium, 24 Hr, U

Specimen Type

Urine


Advisory Information


 



Necessary Information


24-Hour volume is required.



Specimen Required


Supplies: Urine Tubes, 10 mL (T068)

Container/Tube: Plastic, 10-mL urine tube (T068) or clean, plastic aliquot container with no metal cap or glued insert

Specimen Volume: 10 mL

Collection Instructions:        

1. Collect urine for 24 hours.

2. Refrigerate specimen within 4 hours of completion of 24-hour collection.

3. See Trace Metals Analysis Specimen Collection and Transport in Special Instructions for complete instructions.

Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens in Special Instructions for multiple collections.


Reject Due To

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

NA

Specimen Stability Information

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

Specimen Minimum Volume

0.4 mL

Day(s) and Time(s) Performed

Thursday; 8 a.m.

Specimen Retention Time

14 days

Analytic Time

1 day

Reference Values

0-17 years: not established

≥18 years: <0.7 mcg/24 hour

Useful For

An aid in documenting past exposure to gadolinium-containing chelates

Method Name

Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

Test Classification

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

CPT Code Information

83018

LOINC Code Information

Test ID Test Order Name Order LOINC Value
GDU Gadolinium, 24 Hr, U 8201-6

 

Result ID Test Result Name Result LOINC Value
29252 Gadolinium, 24 Hr, U 8201-6
TM101 Collection Duration 13362-9
VL82 Urine Volume 3167-4

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 for magnetic resonance imaging and computer tomography scanning.

 

Gadolinium is eliminated primarily by the renal filtration. In healthy subjects with normal renal function, the plasma half-life of gadolinium is approximately 90 minutes. Patients with reduced renal function exhibit an increased gadolinium excretion half-life.

 

Gadolinium has been associated with nephrogenic systemic fibrosis (NSF) in patients with impaired renal function. In this syndrome, prolonged retention of gadolinium is thought to allow the gadolinium cation to dissociate from its synthetic organic chelator and deposit predominantly in the skin, although other organs may be affected as well. These patients are often severely debilitated by progressive skin thickening and tightening. Fibrosis of skeletal muscle, lungs, liver, testes, and myocardium have also been observed, often with fatal results. Because the ionic radius of gadolinium (3+) is similar to that of calcium (2+), it may also deposit in bone.

 

Three hemodialysis treatments are required to substantially remove gadolinium from patents with impaired renal function; peritoneal dialysis is not effective.

Interpretation

Elevated gadolinium (>0.6 mcg/24 hour) observed in a 24-hour urine specimen collected more than 96 hours after administration of gadolinium-containing contrast media may indicate impaired ability to eliminate gadolinium or continued exposure, suggesting either reduced renal function or exposure to anthropogenic sources. Patients with reduced renal function who have been exposed to gadolinium may have an increased risk to develop nephrogenic systemic fibrosis (NSF).

 

Elevated gadolinium in a specimen collected less than 96 hours after contrast media infusion does not indicate risk of NSF.

 

The normal value is less than 0.7 mcg/24 hour; 95% of unexposed patients will have values below 0.1 mcg/specimen. The lower limit of detection is 0.1 mcg/specimen.

Cautions

Urine gadolinium concentration will be elevated if the specimen is collected less than 96 hours after administration of gadolinium-containing contrast media. This elevation is due to residual gadolinium present from contrast media infusion. Elevated gadolinium in a specimen collected less than 96 hours after contrast media infusion does not indicate risk of nephrogenic systemic fibrosis (NSF).

 

Evaluation of urine for gadolinium content has minimal value in making the diagnosis of NSF. Gadolinium is present in the effluent of metropolitan sewage treatment plants and in the rivers near metropolitan areas. Sewage treatment does not remove gadolinium. Anthropogenic sources of gadolinium could contribute to low concentrations of gadolinium excreted in the urine.

Clinical Reference

1. D'Hease P, De Broe M: Gadolinium. In Handbook on Metals in Clinical and Analytical Chemistry. Edited by HG Seiler, A Sigel, H Sigel. Marcel Dekker, Inc, New York, 1994, pp 365-369

2. Swan SK, Lambrecht LJ, Townsend R, et al: Safety and pharmacokinetic profile of gadobenate dimeglumine in subjects with renal impairment. Invest Radiol 1999;34:443-448

3. Otherson JB, Maize JC, Woolson RF, Budisavljevic MN: Nephrogenic systemic fibrosis after exposure to gadolinium in patients with renal failure. Nephrol Dial Transplant 2007;10:1093-1100

4. Perazella MA: Nephrogenic systemic fibrosis, kidney disease, and gadolinium: is there a link? Clin J AM Soc Nephrol 2007;2:200-202

5. Saitoh T, Hayasaka K, Tanaka Y, et al: Dialyzability of gadodiamide in hemodialysis patients. Radiat Med 2006;24:445-451

6. Leung N, Pittelkow MR, Lee CU, et al: Chelation of gadolinium with deferoxamine in a patient with nephrogenic systemic fibrosis. NDT Plus 2009;2:309-311

7. Girardi M, Kay J, Elston DM, et al: Nephrogenic systemic fibrosis: Clinicopathological definition and workup recommendations. J Am Acad Dermatol 2011;65:1095-1106

8.  Telgmann L, Sperling M, Karst U: Determination of gadolinium-based MRI contrast agents in biological and environmental samples: A review. Analytica Chimica Acta 2013;764:1-16

Method Description

Gadolinium (Gd) in serum and urine is analyzed by inductively coupled plasma-mass spectrometry in standard mode using terbium (Tb) as an internal standard and a plasma matrix calibration.(Leung N, Pittelkow MR, Lee CU et al: Chelation of gadolinium with deferoxamine in a patient with nephrogenic systemic fibrosis. NDT Plus 2009;2[4]:309-311)

Supportive Data

An evaluation of urine gadolinium concentration in healthy human subjects not exposed to gadolinium within 96 hours of specimen collection generated a reference range of less than 0.7 mcg/24 hour (median value 0.2 mcg/24 hour) with no evidence of age or gender trend. Urine gadolinium concentrations observed in Mayo Clinic patients with nephrogenic systemic fibrosis (NSF), either before or after chelation therapy with succimer, were in the range of 2 to 5 mcg/24 hour (ie, succimer had no effect on excretion rate). No peer-reviewed reports of urine gadolinium concentrations associated with NSF were found on literature search.

Urine Preservative Collection Options

Ambient

Yes

Refrigerated

Preferred

Frozen

Yes

6N HCl

Yes

50% Acetic Acid

No

Na2CO3

No

Toluene

Yes

6N HNO3

Yes

Boric Acid

No

Thymol

No