目的探讨不同剂量CT扫描应用 于泌尿结石临床诊断价值。方法 按照入 院挂号时间顺序将200例拟诊泌尿系结石 患者分为对照组与观察组，各100例。对 照组采用常规剂量CT扫描检查(120KV、 150mA)；观察组根据患者体重指数不同 分别采用(100mA、80mA、50mA)低剂量CT 扫描。比较2组患者图像质量评分(IQS) 和容积CT剂量指数(CTDIvol)、扫描敏 感性、特异性、阳性预测值、阴性预测 值。结果 经研究发现，观察组CTDIvol为 (6.5±1.1)与对照组(19.7±1.4)比较， 具有统计学意义(P<0.05)；但2组扫描敏 感性、特异性、阳性预测值、阴性预测 值、IQS比较，无统计学意义(P>0.05)。 结论 相比常规剂量CT扫描来说，临床根 据患者体重指数采用低剂量CT扫描，其图 像质量、特异性、阳性预测值与其相当。 但低剂量CT扫描过程中所产生辐射剂量要 少，因此对患者造成伤害少，更值得进行 推广应用。

Objective Discusses the application of different dose of CT scan in the clinical diagnostic value of urinary calculi. Methods In chronological order according to admission registered 200 cases of suspected urinary calculi were divided into a control group and the observation group, the 100 cases respectively. Control group with conventionaldose CT scan (120KV, 150mA); Observe the different groups were used (100mA, 80mA, 50mA) low-dose CT scans based on patient body mass index. Comparison of the two groups were image quality score (IQS) and volume CT dose index (CTDIvol), scanning sensitivity, specificity, positive predictive value, negative predictive value. Results The study found that the observation group CTDIvol was (6.5±1.1) and the control group (19.7±1.4) compared with statistical significance (P <0.05); but the two groups scanning sensitivity, specificity, positive predictive value, negative predictive value , IQS comparison, no significant difference (P>0.05). Conclusion Compared with conventional dose CT scan, according to body mass index (bmi) in patients with clinical use of lowdose CT scan, the images quality, specificity, positive predictive value and its quite. But low dose CT scanning process produced less radiation dose, therefore cause harm to patients, more worthy of popularization and application.