体重指数及结石CT值预测体外冲击波碎石术结石排空率

The Value of Body Mass Index and Hounsfield Unit on CT as Predictors of Stone-free Rate after Extracorporeal Shock Wave Lithotripsy

目的:探讨体重指数(BMI)及结石CT值是否可以用来预测体外冲击波碎石术(ESWL)结石的清除率。方法:选择2004年4月～2006年7月在本院碎石中心进行体外冲击波碎石的200例上尿路结石患者进行ESWL治疗,结石直径0.5～1cm,治疗前计算BMI,行CT扫描并测定CT值,治疗后依据碎石屑测定结石成分,3个月后根据影像学判断结果把病人分为结石清除组及残余结石组,将BMI及CT值作为预测的相关因素,进行logistic回归分析。结果:163例结石清除,37例结石残余,平均BMI分别为25.5±0.5及31.2±0.7;两组平均CT值分别为557.8±121.5及953.4±170.5,两组上述2项指标比较,差异显著(P<0,05)。logistic回归分析显示结石清除率与BMI及CT值密切相关。结论:BMI及CT值是ESWL结石清除率的重要预测因子,通过治疗前后相关资料进行分析,可为患者选择合理的治疗方法提供参考。

To assess the value of body mass index（BMI） and Hounsfield Unit on CT as predictors of stone-free rate after Extracorporeal Shock Wave Lithotripsy（ESWL）, Methods：We evaluated 200 patients who underwent ESWL for 5 to 10 mm upper urinary tract stones. BMI was calculated for each patient. In addition Hounsfield units （HU） on CT and chemical analysis were performed for each stone. After 3 month, radiographic assessment were done, According to the results patients were categorized into Stone-free（SF） group or Residual-stones（RS） group,Statistical analysis was performed （Logistic regression）, Using BMI and HU value as predictors to assess stone free rates after ESWL. Results：Of the 200 patients,163 were stone-free and 37 had residual stones, Mean BMI in the SF group was 25.5±0.5 versus 31.2±0.7 in the RS group （P 〈0. 05）. Mean HU values between SF and RS groups were significantly different ,557.8±121.5 versus 953.4±170.5 （P 〈 O, 05 ） ,Logistic regression analysis revealed that unsuccessful outcome was significantly related to BMI and HU value, Conclusion：BMI and HU value are significant predictors of stone free rates after ESWL, We believe these findings may be benefit for selecting the preferred treatment option for patients with urinary calculi.