目的 研究自适应统计迭代重建 技术(ASIR)结合低剂量CT扫描中对诊断 泌尿系结石中应用效果。方法 选取我院 2013年12月至2015年12月临床怀疑为泌 尿系结石的患者74例，抽签随机分为两 组，每组37例，进行130kV、250mAs常 规剂量扫描的患者设置为常规剂量组， 进行130kV、30mAs低剂量扫描的患者 设置为低剂量组，运用滤过反投影技术 (FBP)及不同权重ASIR对图像进行重建分 析，比较两组患者CT扫描结石检出率、 诊断灵敏度、特异度以及两组图像质量 及图像噪声评分，比较两组患者CT扫描 后所受辐射剂量。结果 常规剂量组结石 检出率为100%，低剂量组结石检出率为 98.10%；常规剂量组患者FBP图像质量评 分较低剂量组FBP、20%ASIR、40%ASIR图 像质量评分较高(P＜0.05)；常规剂量组 患者FBP图像噪声评分较低剂量组FBP、 20%ASIR、40%ASIR图像噪声评分显著较低 (P＜0.05)；常规剂量组患者经CT扫描后 的CTDIvol、DLP、ED水平较低剂量组显著 较高(P＜0.05)。结论 低剂量CT扫描能显 著降低患者所受辐射量，运用ASIR技术联 合低剂量CT扫描可明显提高图像质量，减 少图像噪声，为泌尿系结石的临床诊断提 供有价值的数据，临床可行性高。

Objective To study application effect of adaptive statistical iterative reconstruction (ASIR) technique combined with low dose CT scan in the diagnosis of urinary calculus. Methods 74 cases suspected clinically as urinary calculus in our hospital from December 2013 to December 2015 were divided by random lot method into two groups (each 37 cases), patients who underwent 130kV, 250mAs conventional dose scan were marked as conventional dose group, patients who underwent 130kV, 30mAs low dose scan were marked as low dose group, filtered back projection technique (FBP) and different weights ASIR were used to reconstruct and analyze images, CT scan calculus detection rate, diagnostic sensitivity, specificity, image quality, image noise score in the two groups were compared, radiation dose after CT scan in the two groups were compared. Results Detection rate of calculus in conventional dose group was 100%, detection rate of calculus in low dose group was 98.10%, FBP image quality score in conventional dose group was significantly higher than low dose group FBP, 20%ASIR, 40%ASIR image quality score (P<0.05), FBP image noise score in conventional dose group was significantly lower than low dose group FBP, 20%ASIR, 40%ASIR image noise score (P<0.05), CTDIvol, DLP, ED level after CT scan in conventional dose group were significantly higher than low dose group (P<0.05). Conclusion Low dose CT scan can reduce radiation dose of patients significantly, application of ASIR technique combined with low dose CT scan can improve image quality significantly, reduce image noise, provide valuable data for clinical diagnosis of urinary calculus, clinical feasibility is high.