DOI: 10.36347/sajb.2016.v04i05.004

Pages: 385-389

The outcomes of extracorporeal shock wave lithotripsy (ESWL) depend on several factors and the stone composition has emerged as the main factor influencing the efficacy of ESWL. The density of the stone varies with composition and the stone attenuation value (SAV) on non-contrast CT can be used to assist in determining the density of urinary calculi in vivo. The aim of this study was to evaluate whether the SAV of urinary calculi on NCCT can be used as an independent predictor of calculus fragmentation by ESWL. The Materials and methods in the study included 50 patients with the single renal calculus of less than 2cm. The Hounsfield unit measured using NCCT. All patients underwent ESWL using the Dornier Compact Sigma Electro Magnetic Shock Wave Emitter. The outcome was evaluated after three months of ESWL session by NCCT. In Results the Patients were divided into three categories according to SAV in NCCT. The overall number of stone-free patients was 46/50 (92.00 %). In 4 patients (8%) ESWL failed and all are of HU>1000 category. In HU>1000 category mean numbers of the shock wave and average energy needed for successful stone disintegration was significantly higher than other two categories. We conclude that the use of NCCT for determining the attenuation values of urinary calculi before ESWL helps to predict treatment outcome. A stone density of > 1165 HU suggests a poor chance of stone disintegration with a Dornier Compact Sigma Lithotripter. The use of this threshold could help to plan alternative treatment in patients with the likelihood of ESWL failure.