[The usefulness of dual-energy radiographic densitometry (DO) in establishing the composition of calculi].

Dual-energy radiographic bone densitometry is utilized to determine the bone mineral content in patients with osteoporosis. The present in vitro experimental study investigated the usefulness of densitometry in determining stone composition and in evaluating the mineral and non mineral phases of the calculus. For the study we analyzed 114 calculi of 6 different chemical composition (calcium oxalate monohydrate, calcium oxalate dihydrate, magnesium ammonium phosphate, phosphate carbonate, uric acid and phosphate oxalate). The phosphate carbonate calculi had the highest mineral density, whereas the uric acid calculi had the lowest and contained more water. Although densitometry appears to be of little value in determining stone composition, it provides information on the mineral and non mineral phases of the calculus.