Clinical Biochemistry

Renal stone analysis (calculi)

Test Background
Kidney stones are solid accretions of dissolved minerals in urine found inside the kidneys or ureters. These are subsequently expelled in the urine stream, leading to ureteric obstruction and distension. Stones form around a central nidus from which a crystalline structure expands and are typically derived of calcium salts (of which calcium oxalate predominates). Other examples of calculi include the (urea-splitting) bacterially-derived struvite (Mg, NH₄ and PO₄), uric acid and cystine.

Clinical Indications

• All renal calculi should be analysed
• Symptoms of nephrolithiases include: renal colic, (acute and spasmodic flank pain) nausea, UTI, haematuria and vomiting

Reference Range

Sample Required
Renal stone

Sample Volume
Ideally 10 mg

Turnaround Time
Up to 6 weeks

Notes
Not currently performed in house; this is a referred test.
Full clinical details should be supplied.