Investigations for Characterizing Single Crystal Phases in Urinary Stones by Means of an Arrangement of Light Microscopy in Combination with Scanning Microscopy
Modern analysis of urinary calculi enables us to determine different structures in a stone, which by chemical analysis could not be identified. The efforts formerly made to discover the genesis of different kinds of stones were based mainly on the classification of stones by their major constituents such as uric acid, calcium oxalate, phosphate, or cystine. Nowadays, stone genesis is investigated in terms of how uric acid, uric acid dihydrate, calcium oxalate monohydrate, as well as dihydrate and the different phosphates such as struvite, carbonate apatite, brushite, and newberyite, develop. But in addition, more attention should be paid to the more difficult problem of the identification of the minor or rare components of urinary calculi. In crystalluria, unusual crystals sometimes appear that are difficult to identify. With sufficient material available, identification by means of x-ray diffraction analysis or IR spectroscopy is no problem. However, with a urinary sediment, crystalline material usually is scarce, although this is not the case when examining urinary calculi. Taking samples from different layers of a stone always represents only an integration over a larger area. Without good spatial resolution, initial nucleation centers of yet unknown components could remain undiscovered. The detection of possible nucleation centers can be carried out on thin sections of urinary calculi. Examination with ordinary light and polarized light microscopy permits localization of the initial phases of stone formation. Based on their double refraction, single crystals in thin sections and urinary sediments can be characterized.
KeywordsUric Acid Stone Formation Calcium Oxalate Urinary Stone Urinary Sediment
Unable to display preview. Download preview PDF.