X-ray analysis of pathological calcifications including urinary stones.

Electron-probe microanalysis (EPM) is an ideal technique with which to study biological calcification. It is particularly effective in identification of crystalline or non-crystalline deposits of minute size in tissues, and in detecting artifacts which may occur during tissue processing. Human aorta, aortic valves, tumours, joint fluid, and calculus specimens were analyzed via scanning electron microscopy (SEM), EPM, transmission electron microscopy (TEM), and selected-area electron diffraction (ED). Crystals found in the specimens were definitively identified by combined SEM-EPM. It is apparent that EPM is an invaluable tool that will potentially improve the acuity of 'in house' laboratory diagnosis of many pathological calcifications.