Composition of urinary calculi by x-ray diffraction. Collected data from various localities. 8. Leeds, England.

SUMMARY An X-ray diffraction study of the composition of upper tract urinary stones from 3 centres in Great Britain shows that the calcium oxalates and the calcium phosphates are the most abundant and frequently occurring crystalline constituents, and that the most common varieties of stones are those composed of pure calcium oxalate and calcium oxalate+calcium phosphate. The relative proportions of these types, however, vary in the different areas. Infection stones consisting of struvite + calcium phosphate are the next important type in the collections from Bristol and Dundee, but there are few of these stones in the collection from the Royal Navy. In a small collection of lower urinary tract calculi from Dundee, stones composed of calcium oxalate + calcium phosphate again predominate, but they are exceeded by infection stones if the different varieties of these are grouped together. Whereas a few composition types dominate the collections of upper urinary tract calculi, there are many more combinations of constituents found in the collection of lower tract stones.