measuring stone free rate after mini percutaneous nephrolithotomy: radiography, ultrasound, or ct scan?

Stone-free rate (sfr) after treatment can be estimated by plain radiography and ultrasonography, or computed tomography (ct) scanning. based on the guidelines, ct is the primary method for sfr estimation after pcnl (percutaneous nephrolithotomy) due to its high sensitivity and wide availability. however, there is an extreme need to minimize unnecessary radiation exposure in patients. the ct scanning is more indispensable in the minimally invasive pcnl (mpcnl) technique to detect small residual stone fragments. finally, we believe that using ct scan in follow up of mpcnl patients, rather than plain radiography and ultrasonography, is more accurate to detect residual fragments and estimate sfr as one of the important outcomes of this operations.