A synchrotron study of bladder urolith architecture

Abstract

The principal aim of this study was to assess a new approach to the characterization of uroliths using synchrotron radiation. To achieve this, a detailed investigation of the crystalline nature of a human bladder urolith has been undertaken. Changes in the phase composition and crystalline mineral nature 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 dimensions of the majority phases (anhydrous uric acid and calcium oxalate monohydrate) are significantly greater in the core region but become progressively smaller 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 analysis has also allowed us to study the change in average crystallite morphology; 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. Evidence of calcium oxalate dihydrate was also found, but only within the outermost region of the urolith.