Evaluation and Comparison of SHA.LIN,S.T.O.N.E.Nephrolithometry Scoring System,and Clinical Research Office of the Endourological Society Nephrolithometry Nomogram for Predicting Stone Free Rate and Postoperative Outcomes after Percutaneous Nephrolithotomy / 中国医学科学院学报

To compare the accuracy of SHA.LIN,S.T.O.N.E.nephrolithometry scoring system,and Clinical Research Office of the Endourological Society(CROES)nephrolithometry nomogram in predicting percutaneous nephrolithotomy(PCNL)outcomes including stone free rate(SFR)and perioperative status. Methods The clinical data of 90 patients with nephrolithiasis undergoing PCNL in department of urology,China-Japan Friendship Hospital from January 2015 to March 2018 were retrospectively analyzed.The general data,stone characteristics,operation approaches,and perioperative variables were recorded.SHA.LIN,S.T.O.N.E.score,and CROES nomogram were assigned according to the computed tomography(CT)findings before surgery.Stone free status was evaluated by kidney-ureter-bladder one month after PCNL.The relationships of SHA.LIN score,S.T.O.N.E.score,and CROES score with SFR,postoperative complications,operation time(OT),length of hospital stay(LOS),estimated blood loss(EBL),and decrease of hemoglobin was evaluated.Receiver operating characteristic(ROC)curves were used to analyze the predictive accuracy. Results The SFR was 72.2%(65/90)and postoperative complications occurred in 33 cases(36.7%).The mean OT was(103.1±39.6)min,the mean EBL was(46.1±53.0)ml,the mean LOS was(15.3±5.2)d,the mean postoperative LOS was(8.5±3.4)d,and the mean decrease of hemoglobin was(16.1±10.2)g/L.Stone-free patients had significantly lower SHA.LIN score(8.23 10.36,=0.000)and S.T.O.N.E.score(7.05 8.16,=0.000)and significantly higher CROES score(188.50 143.89,=0.000)compared to patients with residual fragments.All these scores were not significantly associated with complications(>0.05).On the other hand,all these scores were significantly correlated with OT,EBL,and decrease of hemoglobin(SHA.LIN:=0.006,=0.028,=0.014;S.T.O.N.E.:=0.012,=0.047,=0.011;and CROES:=0.040,=0.045,=0.013).SHA.LIN(=0.001)and S.T.O.N.E.(=0.005)scores were associated with LOS.Logistic regression analysis revealed that SHA.LIN(=2.491),S.T.O.N.E.(=3.030),and CROES(=0.973)scores were significantly associated with stone-free status.ROC curves in predicting SFR showed that there was significant difference in the areas under the curves(AUC)for the SHA.LIN S.T.O.N.E.score [0.808(95% =0.711-0.905) 0.748(95% =0.632-0.864),=0.047].AUC for the CROES score [0.770(95% =0.664-0.877)] showed no significantly different for the SHA.LIN score or the S.T.O.N.E.score(>0.05). Conclusions All these three scoring systems have good predictive accuracy for SFR.SHA.LIN is more precise than S.T.O.N.E.in predicting SFR.However,they can not predict postoperative complications.

Zoeppritz-based AVO inversion using an improved Markov chain Monte Carlo method.

The conventional Markov chain Monte Carlo (MCMC) method is limited to the selected shape and size of proposal distribution and is not easy to start when the initial proposal distribution is far away from the target distribution. To overcome these drawbacks of the conventional MCMC method, two useful improvements in MCMC method, adaptive Metropolis (AM) algorithm and delayed rejection (DR) algorithm, are attempted to be combined. The AM algorithm aims at adapting the proposal distribution by using the generated estimators, and the DR algorithm aims at enhancing the efficiency of the improved MCMC method. Based on the improved MCMC method, a Bayesian amplitude versus offset (AVO) inversion method on the basis of the exact Zoeppritz equation has been developed, with which the P- and S-wave velocities and the density can be obtained directly, and the uncertainty of AVO inversion results has been estimated as well. The study based on the logging data and the seismic data demonstrates the feasibility and robustness of the method and shows that all three parameters are well retrieved. So the exact Zoeppritz-based nonlinear inversion method by using the improved MCMC is not only suitable for reservoirs with strong-contrast interfaces and long-offset ranges but also it is more stable, accurate and anti-noise.