目的 探讨低剂量CT尿路成像(CTU)对输尿管病变的诊断价值。方法 43例有输尿管病变拟行CTU检查的患者随机分为 2组：常规剂量组20例，扫描参数为管电压120KV，管电流350mA；低剂量组23例，扫描参数为管电压120KV，管电流 100-120mA。2名医师采用双盲法对全部病例排泄期输尿管横断面及重组图像进行影像质量评分(IQS)，评估有效剂 量(ED)及临床诊断符合率。结果 2组间排泄期输尿管横断面及重组图像IQS、临床诊断符合率差异无统计学意义(P ＞0.05)；低剂量组平均ED[(12.95±1.56)mSv]较常规剂量组平均ED[(43.20±2.05)mSv]下降70.02%，差异有统计 学意义(P＜0.01)。结论 低剂量CTU在显著降低辐射剂量的同时，获得的影像可以满足临床对于诊断输尿管病变的 质量要求。

Objective To evaluate the applied value of low-dose CT urography (CTU) for the diagnosis of ureteral diseases. Methods 43 patients with ureteral diseases recruited in this study were divided into two groups. Normal-dose group: twenty of them underwent CTU with tuber voltage of 120 kv and tuber current of 350 mA. Low-dose group: the other twenty-three patients underwent CTU with 120 Kv and 100-120 mA. The Image quality scores (IQS) of both axial and reformatted images in excretory phase of ureters were assigned by two radiologists with double blind method, and the effective dose (ED) as well as the diagnostic coincidence rate were also evaluated. Results There was no statistical difference in the IQS and the diagnostic coincidence rate between the two groups(P>0.05). All images quality can meet diagnostic requirement. The average value of ED of normal-dose group was (43.20±2.05) mSv. The average value of ED of low-dose group was (12.95±1.56) mSv, reducing 70.02% the intrinsic dose compared to normal-dose group (P<0.01). Conclusion Low-dose CT urography can decrease markedly the radiation dose, and the images are satisfactory for the diagnosis of ureteral diseases.