螺旋CT衰减值预测尿路结石成分及对碎石影响的体内研究

Evaluation of Predicting Urinary Calculi Chemical Composition and Effect on ESWL with the Value of Hu on CT

目的研究螺旋CT对体内尿路结石化学成份的预测以及在体外震波碎石中的价值。方法选取本院2008年至2010年尿路结石患者117例,均在治疗前行螺旋CT平扫,测结石CT值并对治疗后获取的结石成分进行分析;选择结石大小适合体外震波碎石(ESWL)的患者,用结石CT值预测ESWL的结石粉碎率和排空率。结果所有结石的CT值为323～1 580 Hu。单一结石成分仅33例(28.21%),包括一水草酸钙、碳酸磷灰石、无水尿酸、二水磷酸氢钙和二水草酸钙结石,CT值分别为(693±128)Hu、(1 233±241)Hu、(368±38)Hu、1 580 Hu和73 Hu;混合性结石84例(71.80%),混合结石主要含两种化学成分,CT值在相应两种成分纯结石的CT值之间。一水草酸钙结石、碳酸磷灰石结石、无水尿酸结石、一水草酸钙+碳磷灰石结石、碳酸磷灰石+一水草酸钙结石、无水尿酸+碳磷灰石结石之间CT值的差异有统计学意义(P<0.01),一水草酸钙结石与一水草酸钙+二水草酸钙、六水磷酸镁胺+碳酸磷灰石之间CT值差异无统计学意义(P>0.05)。二水草酸钙结石和二水磷酸氢钙结石各1例,CT值为673 Hu和1 580 Hu,未参与统计分析。117例患者中结石排空者81例(69.23%),结石残留者36例(30.77%),其CT值分别为(754±146)Hu和(1 068±247)Hu,2者差异具有统计学意义(P<0.01)。结论结石CT值能在一定程度上预测体内尿路结石成分,而且还能预测体内尿路结石ESWL后结石的排空率和失败率。CT值低者则ESWL后结石容易粉碎和易于排空;CT值高者结石的粉碎率和排空率较低,此类患者可考虑选择输尿管镜下取石碎石术、经皮肾镜取石碎石术。

Objective To study the value of Hu on CT for predicting urinary calculi chemical composition in body and ESWL.Methods 117 urinary calculi were chosen that had computerized tomography and measured the value of Hounsfield unit on CT before therapy and had ESWL owing to calculi composition and calculi size by calculi composition after therapy.Using the value of Hu on CT Predicted ESWL lithotripsy and stone-free rate by statistics analyses.Results The value of Hu in all stones averages 323~1 580.Only 33 cases（28.21%） has one composition including Calcium oxalate monohydrate,Carbonated apatite,Anhydrous uric acid,Calcium oxalate dihydrate,the value was 693±128 Hu,1 233±241 Hu,368±38 Hu,1 580 Hu,673 Hu,respectively.Mixed stones were 84 cases（71.80%） mainly including two compositions.The value of Hu varied between the values of two one-composition calculi.By one-way classification,there was a statistically significant difference excepting Calcium oxalate monohydrate stones and mixed stones with Calcium oxalate monohydrate and Calcium oxalate dihydrate or Carbonated apatite and Magnesium ammonium phosphate hexahydrate,Calcium oxalate dehydrate and Dicalcium phosphate didrate because of less cases.the stone-free rate accounted for 69.23%（81/117） and the residual-stone rate accounted for 30.77%（36/117）.There was a statistically significant difference between stone-free group and residual-stone group（average value 754±146 Hu in former and 1 068±247 Hu in latter）.Conclusion The value of Hu on CT could predict calculi composition in some degree and stone-free rate and failure rate after ESWL.The lower the value of Hu was,the easier in ESWL was.The stones with higher value of Hu on CT fitted URL or PCNL.