Microcomposition of Human Urinary Calculi Using Advanced Imaging Techniques

Purpose: Common methods of commercial urolithiasis analysis, such as light microscopy and Fourier transform infrared spectroscopy, provide limited or no information on the molecular composition of stones, which is vital when studying early stone pathogenesis. We used synchrotron radiation based microfocused x-ray fluorescence, x-ray absorption and x-ray diffraction advanced imaging techniques to identify and map the elemental composition, including trace elements, of urinary calculi on a mu m (0.0001 cm) scale. Materials and Methods: Human stone samples were obtained during serial percutaneous nephrolithotomy and ureteroscopy procedures. A portion of each sample was sent for commercial stone analysis and a portion was retained for synchrotron radiation based advanced imaging analysis. Results: Synchrotron radiation based methods of stone analysis correctly identified stone composition and provided additional molecular detail on elemental components and spatial distribution in uroliths. Resolution was on the order of a few mu m. Conclusions: Knowledge of all elements present in lithogenesis at this detail allows for better understanding of early stone formation events, which may provide additional insight to prevent and treat stone formation.