Calculi - urinary
Last updated: Thursday, 08, April, 2004
MBS Online Search Page: Click here for details
Calculus obtained from spontaneous passage or surgical intervention
Commonly a series of spot tests are performed on pulverised, dissolved calculus. The mineral composition is then deduced from the relative amounts of each compound.
Calcium:spectrophotometry, atomic absorption spectrophotometry
Infrared spectroscopy and X-ray diffraction provide more definitive identification.
Identification of risk factors for stone recurrence. May guide extracorporeal lithotripsy.
Stones containing calcium may indicate hypercalciuria.
Uric acid stones, or stones with a uric acid nidus, may indicate strongly acidic overnight urine or hyperuricosuria.
Oxalate stones may indicate hyperoxaluria. Magnesium ammonium phosphate ('triple phosphate') stones indicate bacterial infection.
Cystine stones indicate cystinuria.
Xanthine stones indicate xanthinuria or treatment with allopurinol.
Stones that do not dissolve in acid are usually factitious.
Tiselius HG et al. Eur Urol 2001; 40(4): 362-3671.