“…By increasing surgeon experience and technological development of tools using in PNL surgery increase the success of the surgery and decrease the complication rate. However, it is known that the success of PNL is also affected by some other influencers such as hydronephrosis, stone location, and as well as Hounsfield unit (HU) [3]. Gucuk et al [4] showed that the higher HU values increase the stone-free rate and HU is an independent predictive factor affecting the success of PNL.…”