【Results】The median age was 65 years. Additional therapies were performed in 16 patients. The stone-free rate was 80.2% (154/192). Multivariate analysis revealed a significant difference between the residual and stone free groups in the maximum diameter (median 13.0 vs 9.0 mm, p=0.0108) and average CT value (median 1,259 vs 912 HU, p=0.0070). The maximum CT value of the maximum cut surface was constant, but not the average CT value, according to the guideline on urolithiasis. There was no significant difference between them in this study.