In Vıvo Evaluatıon of the Chemıcal Composıtıon of Urınary Stones Usıng Non-Contrast Helıcal Computerized Tomography

ABSTRACT: Aim: To determine the density and chemical structure of renal stones by using in vivo low dose helical computerized tomography. Methods: 79 patients with renal or uretheral stones were included in our study who were going to have extracorporeal shock wave lithotripsy (ESWL) or planned to go through urinary stone surgery due to renal stones. All stone densities were measured in Hounsfield Unit by low dose abdominal non-contrast helical computed tomography examination. Marconi MX 8000 CT system with 4 detectors was used for the CT examination. X-Ray diffractometry was used in the analyses of all stones. Results: The stone type was found to be one type, and mixed stone in 27 patients. The largest group among the mixed stones included whevellite-weddellite stone with 17 patients. Uric acid stones had the smallest, whevellite stones had the highest density. The difference between the density values of uric acid and cystine stones and the other stone types were statistically significant. Conclusion: Non-contrast helical computed tomography used in the diagnosis can also be used in the in vivo determination of the stone composition. It can be very helpful to define stone compositions by imaging studies to provide suitable therapeutic alternatives.