A synchrotron study of bladder urolith architecture

The principal aim of this study was to assess a new approach to the charact erization of uroliths using synchrotron radiation. To achieve this, a detai led investigation of the crystalline nature of a human bladder urolith has been undertaken. Changes in the phase composition and crystalline mineral n ature have been measured from the urolith core center to its outer surface. Data were collected using a microbeam, synchrotron probe, and image plate. Rietveld analysis has enabled us to determine that the unit cell dimension s of the majority phases (anhydrous uric acid and calcium oxalate monohydra te) are significantly greater in the core region but become progressively s maller from the outer to inner regions. The crystallites of both phases are also shown to possess significant radial orientation which varies through the urolith and reaches a maximum at a point of principal fracture. The ana lysis has also allowed us to study the change in average crystallite morpho logy; the crystallites of both phases are shown to decrease in size toward the outer parts of the urolith although this is in a nonuniform fashion. Ev idence of calcium oxalate dihydrate was also found, but only within the out ermost region of the urolith. (C) 2000 International Centre for Diffraction Data. [S0885-7156(00)00202-5].