静脉肾孟造影后64层CT尿路成像对输尿管结石的诊断价值

目的探讨静脉肾孟造影（IVP）后64层CT尿路成像（CTU）对输尿管结石的诊断价值；探讨肾实质厚度、输尿管管径推测CT延迟扫描时间的可行性。方法收集B超提示输尿管结石，行静脉肾盂造影的患者共36例，患者行IVP检查后接受64层CT平扫，将上述原始资料传送至工作站，用多平面重建（MPR）及曲面重建（CPR）进行图像后处理，比较KUB＋IVP与CTU的诊断输尿管结石阳性率，对CTU中尿路延迟显影者，测量肾实质厚度及输尿管直径并取平均值，分析它们与延迟显影时间的关系。结果①36例输尿管结石中，KUB＋IVP诊断正确者20例，CTU诊断正确者31例，两者差异有统计学意义（X^2=8．13，P〈0．05）；@CTU中，随着肾实质厚度的变薄和输尿管直径的增粗，输尿管显影逐渐延迟。当肾实质的平均厚度减至0．99mm时，输尿管不显影。梗阻段上方输尿管管径粗于17mm者，输尿管不显影。结论①CTU对输尿管结石诊断率优于KUB＋IVP；②患侧肾实质的平均厚度、输尿管管径有望成为推测增强扫描CTU延迟扫描时间点的指标。

Diagnostic Values in Ureteral Stones with 64-slice CT Urography Following Intravenous Pyelography

Objective To explore the diagnostic values of ureteral stones with 64-slice computed tomographic urography （CTU） following intravenous pyelography （IVP）, and the feasibility of speculating on the delayed CT scan time with the thickness of renal parenchyma and the caliber of ureter. Materials and methods 36 patients who were diagnosed with ureteral stones by B ultrasound, underwent IVP and later or delayed CTU. The data of all the patients were transferred to workstation for 3D reconstruction of multiple plane reconstruction （MPR） and curved plane reformation （CPR）. to compare the diagnostic accuracy for ureteral stones between the methods of KUB ＋ IVP and CTU. As to the delayed visualization of urinary tracts in CTU, the average values of renal parenchymal thickness and ureteral diameter were measured, and their relationship with the delayed time of visualization was studied. Result ①20 （20/36） cases of ureteral stone were confirmed by KUB ＋ IVP, 31 （31/36） by CTU. Between them, there was significant difference （X^2 =8.13, P 〈0. 05） ;②In CTU, ureteral visualization was delayed gradually along with the decrease of renal parenchemal thickness and the increase of ureteral diameter. When the mean thickness of renal parenchyma decreased below 0. 99 mm, or when the mean diameter of ureter increased to 17 mm, ureter was not visualized. Conclusion ①CTUs were superior to KUB ＋ IVP for accuracy to chagnose ureteral stones; ②The mean values of renal parenchymal thickness and ureteral diameter can be regarded as a promising index for speculating the ideal delay-time ooint of CTU.