目的 探讨低剂量CT扫描技术联 合图像重建在泌尿系结石患者诊治中的作 用。方法 选取我院2014年5月至2015年5 月60例泌尿系结石患者为研究对象，以病 理结果为准。使用常规剂量、低剂量进行 CT扫描各一次，并将其分为常规剂量组与 低剂量组，且对低剂量组分别使用滤过反 投影技术及域迭代重建算法对图像进行重 建，比较两组全部结石检出率、肾结石检 出率、输尿管结石检出率，记录患者的CT 容积剂量指数(CT volume dose index, CTDIvol)；比较不同图像重建技术的图像 噪声、信噪比等图像质量，并进行图像 分析。结果 低剂量组全部结石检出率、 肾结石检出率、输尿管结石检出率分别为 96.67%、93.75%及100.00%；而常规剂量 组各部位结石检出率均为100.00%。两组 检查方法的结石检出率比较无统计学意 义(P>0.05)。常规剂量组的平均CTDIvol 为(18.56±3.72)mGy，低剂量组为 (2.91±0.34)mGy，低剂量组所受到的辐 射剂量比常规剂量组降低84%，有统计学 意义(P<0.05)。低剂量IRIS算法图像平均 噪声低于FBP算法图像，平均信噪比高于 FBP算法图像，有统计学意义(P<0.05)。 结论 低剂量CT扫描技术联合IRIS对图像 进行重建，可保证图像质量，且对泌尿系 结石的检出率与常规剂量检出率无明显差 异，可用于泌尿系结石的诊断。

Objective To explore the effect of low dose CT scanning technology combined with image reconstruction in diagnosis and treatment of urinary calculi. Methods Sixty patients with urinary calculi in our hospital from May 2014 to May 2015 were selected as the research objects, pathological results were used as the criterion. They were divided into routine dose group and low dose group, all underwent conventional dose and low dose CT scanning. Filtered back projection technique (FBP) and iterative reconstruction algorithm (IRIS) were used to reconstruction in low dose group. Detection rate of all stones, detection rate of kidney stones, detection rate of ureteral calculus in the two groups were compared and CT volume dose index (CTDIvol) of patients were recorded; pattern noise, noise-signal ratio of the images by different image reconstruction technology were compared. Results There was no significant difference in detection rate of all stones, detection rate of kidney stones, detection rate of ureteral calculus btween low dose group (96.67%, 93.75%, 100.00%) and routine dose group (100.00%, 100.00%, 100.00%) (P>0.05). Average CTDIvol of routine dose group was (18.56±3.72)mGy, low dose group was (2.91±0.34)mGy, the radiation dose of the latter was decreased 84% compared to the former(P<0.05). Average noise of low dose IRIS algorithm image was significantly lower than FBP algorithm image while the average noise-signal ratio was significantly higher than it (P<0.05). Conclusion Low dose CT scanning technology combined with IRIS to reconstruct image can ensure quality of image. The detection rate of urinary calculi has no significant difference from detection rate of conventional dose, can be used in diagnosis of urinary calculi.