title: Computed tomographic analysis of urinary calculi.
abstract: Excised urinary calculi were subjected to computed tomographic (CT) scanning in an attempt to determine whether CT attenuation values would allow accurate analysis of stone composition. The mean, maximum, and modal pixel densities of the calculi were recorded and compared; the resulting values reflected considerable heterogeneity in stone density. Although uric acid and cystine calculi could be identified by their discrete ranges on one or more of these criteria, calcium-containing stones of various compositions, including struvite, could not be distinguished reliably. CT analysis of stone density is not likely to be more accurate than standard radiography in characterizing stone composition in vivo.
mesh_terms: D002129:Calcium Oxalate; D002130:Calcium Phosphates; D003553:Cystine; D006801:Humans; D008274:Magnesium; D017616:Magnesium Compounds; D010710:Phosphates; D000069877:Struvite; D014057:Tomography, X-Ray Computed; D014527:Uric Acid; D014545:Urinary Calculi / Q000000981:diagnostic imaging*
chemical_list: D002130:Calcium Phosphates; D017616:Magnesium Compounds; D010710:Phosphates; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; D002129:Calcium Oxalate; D014527:Uric Acid; D003553:Cystine; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; D000069877:Struvite; D008274:Magnesium; C485829:calcium phosphate, dibasic, anhydrous; C494366:calcium phosphate, dibasic, dihydrate