CT值对上尿路结石体外冲击波碎石后结石排空率的预测价值

目的了解非增强螺旋CT的结石CT值对预测上尿路结石体外冲击波碎石(ESWL)后结石排空率的价值。方法对52例结石大小在0.5cm~1.5cm、需行ESWL的上尿路单发结石患者先行非增强螺旋CT检查,并测定结石CT值,经ESWL后复查B型超声及肾、输尿管、膀胱检查,随访3个月,根据碎石屑残留与否,将52例患者分结石排空组及结石残留组(将残留碎石屑<3mm者归入结石排空组)。统计学分析两组间患者的基本特征、结石CT值、能量冲击次数。结果结石排空者36例(69.2%),结石残留者16例(30.8%),总的结石排空组与残留组的结石平均CT值分别为580HU±195HU和1032HU±271HU(t=6.842,P<0.01),差异有统计学意义;总的结石排空组与结石残留组的能量平均冲击次数分别为1527次±723次和2613次±519次(t=5.407,P<0.01),差异有统计学意义。结石CT值和能量冲击次数的OR值分别为0.993(95%CI0.988-0.998)、0.998(95%CI0.997-1.000)。结论非增强螺旋CT的结石CT值能预测体内上尿路结石ESWL后结石的粉碎率和排空率。CT值低者ESWL后结石容易被粉碎和易于排空;CT值高者结石的粉碎率和排空率明显下降,此类患者则可考虑选择输尿管镜下取石碎石术、经皮肾镜取石碎石术。

Value of Hounsfield unit on CT in prediction of stone-free rate of upper urinary calculi after extracorporeal shockwave lithotripsy

OBJECTIVE: To study the value of Hounsfield unit (HU) on CT in prediction of stone-free rate of upper urinary calculi after extracorporeal shockwave lithotripsy (ESWL). METHODS: Fifty-two patients suffering from solitary stone in the upper urinary tract 0.5 - 1.5 cm in size, 34 males and 18 females, aged 15 - 77, underwent non-contrast helical computerized tomography (NCHCT), and then ESWL. One day, 2 weeks, 4 weeks, and 3 months after the ESWL the patients underwent kidney, ureter, and bladder examination and B mode ultrasonography. The patients with the residual fragments less than 3 mm in size were categorized into the stone-free group. The relationship among the HU, number of shock wave, and the characteristics of the patients were analyzed. RESULTS: Thirty-six of the 52 patients were categorized into the stone-free group (69.2%) and 16 of the 52 were categorized into the residual stone group (30.8%). The CT value of the stone-free group was 579.65 +/- 194.65 HU, significantly lower than that of the residual stone group (1032.18 +/- 270.49 HU, t = 6.842, P < 0.01). The number of shock wave of the stone-free group was 1526.67 +/- 723.01, significantly lower than that of the residual stone group (2612.50 +/- 518.81, t = 5.407, P < 0.01). The OR values for the HU and number of shock wave were 0.993 (95% CI: 0.988 - 0.998) and 0.998 (95% CI: 0.997 - 1.000). CONCLUSION: The HU value on pretreatment NCHCT of the upper urinary tract stones can be used to predict the stone-free rate after ESWL. ESWL is not indicated to the patients of upper urinary tract stones with high values of HU.