Sorted By Test Name - Mayo Medical Laboratories

GDU
89301
GDT
89302
Johannessen SI, Tomson T: Pharmacokinetic variability of newer antiepileptic drugs: when is monitoring
needed? Clin Pharmacokinetics 2006;45(11):1061-1075
Gadolinium, 24 Hour, Urine
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 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.
Useful For: As an aid in the diagnosis of nephrogenic systemic fibrosis
Interpretation: Elevated gadolinium (>0.5 mcg/specimen) observed in a 24-hour urine specimen
collected >48 hours after administration of gadolinium-containing contrast media indicates impaired
ability to eliminate gadolinium. These patients have an increased risk of developing nephrogenic systemic
fibrosis (NSF). Elevated gadolinium in a specimen collected