Application Of Non-contrast CT In Evaculating Efficacy Of Extracorporeal Shock Wave Lithotripsy In The Management Of Ureteral Calculi

Objective:To explore the relevant parameters of non-contrast CT in predicting the effect of extracorporeal shock wave lithotripsy(ESWL)in the treatment of single ureteral calculi,and to provide a reference for the selection of clinical treatment options.Methods:A retrospective study of 106 patients with single ureteral calculi diagnosed by non-contrast CT and treated with ESWL in the Second Hospital of Tianjin Medical University from January 2019 to October 2019 and were divided into successful group and failure group according to the excretion of stone.Using SPSS23.0 statistical software,the database was established and compared with age,sex,body mass index(BMI),stone side,stone location,stone size,stone surface area,stone volume,stone-to-skin distance(SSD),the degree of hydronephrosis,the CT value of stone,and the thickness of the ureteral wall(UWT).X~2test or t test were used for univariate analysis to analyze the factors related to the success rate of treatment.Logistic regression analysis was used for multivariate analysis to find out the most important factors to establish the prediction model.The optimal truncation value,sensitivity and specificity were measured by ROC curve.Results:There were 58 successful and 48 failed cases and univariate analysis showed that the location of stone,the degree of hydronephrosis,the CT value of stone and stone size,surface area and volume were related to the therapeutic effect of ESWL.The results of logistic multivariate analysis showed that the CT value of stone(OR=1.003 95%CI 1.001～1.006 P=0.012)and stone surface area(OR=1.082 95%CI 1.001～1.170 P=0.048)constituted independent predictive factors of ESWL.The predictive model was established(logit P=0.079×stone surface area 0.003×stone CT value-2.374).ROC curve analysis of stone surface area(AUC=0.887 optimal cut-off value 62.505mm~2),stone CT value(AUC=0.811 optimal cut-off value973HU),predictive model(AUC=0.908 cut-off value 6.027),and the success rate of treatment below the predictive model cut-off value was 87.9%.Conclusion:Non-contrast CT could predict the result of treatment of single ureteral calculi with ESWL and CT value and stone surface area are important predictors ESWL treatment may be preferred in patients below the model threshold with CT value less than 973HU and stone surface area less than 62.505mm~2.