Ultrasonic Studies on Artificial Kidney Stone Models

Standardized and reproducible artificial kidney stone models are necessary and important for performing comparative studies in order to improve stone treatment modalities. Artificial kidney stone models made out of natural substances viz. tri-Calcium phosphate (Whitlockite) and Calcium hydrogen ortho phosphate dihydrate (Brushite) were prepared by pharmaceutical methods involving granulation, tableting and coating. These stones are found be very much similar to real kidney stones. Ultrasonic velocity measurements were made using longitudinal and transverse probes and the corresponding wave impedances and dynamic elastic moduli of these two groups of artificial stone models were studied and reported. The compositions of the stones were verified using FTIR and X-ray diffraction analysis. The results indicate that the properties of artificial stones made of natural stone materials are comparable to renal calculi of the same chemical composition. These data also suggest that these stone phantoms are suitable for performing standardized and reproducible in vitro investigations, especially with regards to fragility of kidney stones during shock wave lithotripsy.