评价Karl迭代重建技术低剂量CT对泌尿系小结石显示的影响  

The evaluation:the effects of low-dosage CT with Karl iterative reconstruction technique on the display for small calculi of urinary system

作　　者：张铭 尹小花 杨兆杰 周慧 ZHANG Ming;YIN Xiao-hua;YANG Zhao-jie(Department of Radiography,Jiading District Central Hospital Affiliated to Shanghai University of Medicine&Health Sciences,Shanghai 201800,China)

机构地区：[1]上海健康医学院附属嘉定区中心医院放射影像科

出　　处：《中国医学装备》2019年第11期23-26,共4页China Medical Equipment

基　　金：上海市嘉定区农业和社会事业科研项目(JDKW-2016-W05)“Karl3D迭代重建技术对胸部CT图像质量影响的研究”

摘　　要：目的:评价Karl迭代重建技术低剂量CT对泌尿系小结石显示的影响。方法:选择经常规腹部CT检查及低剂量CT随访复查的60例泌尿系小结石患者,根据CT检查及复查时CT扫描剂量的不同,将患者分为常规剂量组和低剂量组,每组60例。常规剂量组管电压为120 kVp,管电流为240 mAs,滤波反投影(FBP)重建图像;低剂量组管电压为120 kVp,管电流为120 mAs,随访使用Karl 5级重建图像。比较两组X射线有效辐射剂量(ED)、图像噪声(PN)、信噪比(SNR)及图像主观质量和结石检出率。结果:低剂量组与常规剂量组相比,有效辐射剂量减少49.8%,其差异有统计学意义(t=72.57,P<0.001);两组图像的PN、SNR及主观评分无统计学差异(P>0.05);两组泌尿系结石检出率无明显差异(P>0.05)。结论:降低常规CT扫描剂量电流50%,并采用Karl 5级重建图像,可获得与常规剂量FBP重建图像相同的质量,且泌尿系小结石检出率无明显差异。Objective:To evaluate the effects of low-dosage computed tomography(CT)with Karl iterative reconstruction technique for small calculi of urinary system.Methods:60 patients with small calculi of urinary system who underwent conventional CT examination and follow-up reexamination of low-dosage CT were involved in this study.According to the differences of scan dosage of CT in examination and reexamination,these patients were divided into conventional group and low-dosage group(60 cases in each group).The tube voltage and tube current of conventional group were 120 kVp and 240 mAs,respectively,and filtration back projection(FBP)algorithm was used to reconstruct image.And the tube voltage and tube current of low-dosage group were 120 kVp and 120 mAs,respectively,and Karl 5 grade was used to reconstruct the images in follow-up.The effective dose(ED),pattern noise(PN),signal-to-noise ratio(SNR),subjective quality of image and the relevance ratio of the calculus of X-ray between two groups were compared.Results:Compared with the conventional-dosage group,the effective radiation dosage of low-dosage group was significantly reduced by 49.8%(t=72.57,P<0.001),and the differences of PN,SNR and subjective quality scores between two groups were no significant(P>0.05).And the difference of relevance ratio of the calculi of urinary system between two groups was no significant(P>0.05).Conclusion:Reducing the current of conventional-dose CT by 50%and using Karl 5 grade to reconstruct image can obtain the same image quality with that of FBP reconstruction by conventional-dose.And there is no significant difference in the relevance ratio of the calculi of urinary system.

关 键 词：泌尿系结石 低剂量CT Karl迭代算法 滤波反投影 

分 类 号：R691.4[医药卫生—泌尿科学]