泌尿系结石螺旋CT低辐射量扫描的临床应用  

The clinical application of low dose spiral CT in diagnosis of urinary calcali

作　　者：汪素涵[1] 孔曙兵[1] 陈浩[1] 余开湖[1] 

机构地区：[1]咸宁学院临床医学院医学影像学系,湖北437100

出　　处：《放射学实践》2012年第5期536-539,共4页Radiologic Practice

摘　　要：目的:探讨螺旋CT低剂量扫描在泌尿系结石诊断中的临床应用价值。方法:对75例临床怀疑泌尿系结石患者根据就诊顺序分为3组:标准剂量组、低剂量组1和低剂量组2,标准剂量组采用120kV,180mA,螺距0.938进行扫描;低剂量组1和低剂量组2分别采用管电流120mA、80mA进行扫描,其它扫描条件与标准剂量组相同。记录每次扫描的放射容积CT剂量指数(CTDIvol)、剂量长度乘积(DLP)和有效剂量(ED)。由两位具有10年以上CT工作经验的医师进行影像诊断和图像质量评估,计算标准剂量和低剂量CT检查诊断泌尿系结石的敏感度、诊断符合率和阳性预测值。对所有图像进行主观质量评分,并测量其客观噪声值。结果:两个低剂量组与标准剂量组比较,CT剂量指数分别减少29.7%和55.5%,低剂量组1、2对泌尿系结石诊断的敏感度均为93.8%,诊断符合率分别为96.0%和95.5%,阳性预测值分别88.2%和100%,与标准剂量组比较差异均无统计学意义。图像质量方面,尽管剂量降低后图像噪声有所增加,但所有图像质量仍符合诊断要求。结论:低剂量螺旋CT扫描能满足泌尿系结石的诊断要求,大大降低了受检者的辐射剂量。Objective：To study the possibility of low-dose spiral CT scanning in the diagnosis of urinary stone.Methods：Seventy-five patients with clinical presentations suspicious for urinary stone were randomly divided into 3 groups：standard-dose group,low dose group 1 and group 2.Standard dose group adopted 120kV,180mA,pitch 0.938：1 for scanning,low-dose group 1 and group 2 used low-dose tube current 120mA and 80mA respectively,and other scanning conditions were the same as the standard dose group.The volume CT dose index（CTDIvol）,the dose-length product（DLP） and effective dose（ED） were recorded.Two physicians with more than ten years experience were responsible for making imaging diagnosis and image quality assessment,and calculated the sensitivity,accuracy and positive predicative value in the diagnosis of urinary calculi by standard dose and low dose CT examinations respectively.The subjective quality grading was made of all images and the objective noise value was measured.Results：In the two low-dose groups,as compared with the standard dose group,CT dose index（mGy） was decreased by 29.7% and 55.5%,sensitivity was both 93.8%,accuracy was 96.0% and 95.5% and the positive predictive value was 88.2% and 100%.The differences between the two low-dose groups and the standard dose group were not statistically significant.As to the image quality,although the low-dose scan had increased the noise,all images could meet the diagnostic requirements.Conclusion：Low-dose spiral CT scans can normally diagnose urinary tract stones,greatly reduce the radiation dose for patients.

关 键 词：泌尿系结石 辐射剂量 体层摄影术 X线计算机 

分 类 号：R691.4[医药卫生—泌尿科学] R814.42[医药卫生—外科学]