D. Herremans et al., IN-VITRO ANALYSIS OF URINARY CALCULI - TYPE DIFFERENTIATION USING COMPUTED-TOMOGRAPHY AND BONE DENSITOMETRY, British Journal of Urology, 72(5), 1993, pp. 544-548
Thirty-six urinary stones were studied by computed tomography and bone
densitometry in order to find a correlation between the chemical comp
osition of the stones and the densitometric data. In vitro, the more c
ommon cases of lithiasis can be divided into 3 main groups: uric acid,
cystine and the calcium salts, e.g. calcium oxalate monohydrate, calc
ium oxalate dihydrate and calcium phosphate. Struvite stones fall betw
een the second and third groups. Computed tomography and bone densitom
etry can differentiate between the groups, provided that the value of
the ''stone mineral or calcium content'' is correlated with the true c
alculated volume of the stone (resulting in the specific stone density
) instead of the projection area (resulting in the area density). This
is only possible in vitro. The in vivo application of these technolog
ies in the treatment of stones of unknown composition could provide im
portant information, but major restrictive factors pose difficulties.
Further clinical studies are necessary, especially to define the role
of bone densitometry.