Radiographic Parameters in Non-Contrast Computed Tomography Predict the Success of Percutaneous Nephrolithotomy

: Aim: To evaluate whether non-contrast Computed Tomogram (CT) parameters (stone density, localization, size & degree of pelvicalceal system dilatation) predict the outcome of percutaneous Nephrolithotomy (PCNL). Method: This study included 68 patients (43 male & 25 female) with renal calculi scheduled for PCNL. They were examined by non-contrast CT to determine calculus size, calculus density, calculus location & degree of pelvicalceal system dilatation. Ultrasound at scheduled PCNL follow-up one and two months later and undertaken by 2 radiologist at the same unit (HD11XE Philips 2010 unit) checked for residual stones. Stones equal or more than 4 mm in largest diameter was regarded as significant. Result : CT parameters that were associated with more residual stones ( P value <0.001) included density less than 700 HU, upper calyx location, presence of preoperative hydronephrosis and large stone size. Conclusion: pre - operative CT can predict the outcome of PCNL. Stone parameters that predict the oucome of PCNL included stone density, less than 700 HU, upper calyceal stone, large size stone & the presence of pre-operative hydronephrosis.