探讨个体化管电压超低剂量CT结肠造影的可行性  

Feasibility of Ultra-Low Dose CT Colonography with Individualized kVp

作　　者：赵明月 刘义军[1] 张子敬 魏巍 刘磊[1] 周宇婧 陈安良[1] 刘爱连[1] 李贝贝 王旭[1] ZHAO Mingyue;LIU Yijun;ZHANG Zijing(Department of Radiology,the First Affiliated Hospital of Dalian Medical University,Dalian 116011,P.R.China)

机构地区：[1]大连医科大学附属第一医院放射科,116011

出　　处：《临床放射学杂志》2021年第11期2201-2205,共5页Journal of Clinical Radiology

摘　　要：目的探究基于体质指数(BMI)个体化管电压结合高权重ASIR-V行超低剂量CT结肠造影(CTC)的可行性。方法搜集行CTC患者90例,男54例,女36例,年龄31~81岁。根据CTC临床诊断需求,患者需行仰卧位和俯卧位两次扫描,仰卧位(A组)按BMI选择不同管电压,共分三组(每组30例):A1组BMI<23 kg/m^(2)采用70 kVp;A2组BMI 23~25 kg/m^(2)采用80 kVp;A3组BMI>25 kg/m^(2)采用100 kVp,应用80%ASIR-V标准算法重组图像。俯卧位(B组,对应A组BMI分为B1、B2、B3组)采用常规低剂量扫描,管电压120 kVp,应用30%ASIR-V标准算法重组图像,其余扫描参数均同A组。记录容积CT剂量指数(CTDIvol)、剂量长度乘积(DLP)。应用AW 4.7工作站测量图像腰大肌及结肠空气CT值和噪声(SD)值,计算信噪比(SNR)及对比噪声比(CNR),由两名观察者对CTC重组图像进行主观质量评分,比较评分一致性、主客观图像质量及辐射剂量。结果A组图像噪声小于B组(P<0.05),CT值、SNR、CNR均大于B组(P<0.05);两名观察者对图像质量主观评分无统计学差异(P>0.05),一致性较好(Kappa值0.613~0.930),均满足诊断要求;A1~A3组DLP(mGy·cm)分别为75.85±9.75、152.12±19.58、245.00±67.04,与B组相比大幅度降低,分别下降64.5%、48.3%、33.4%。结论根据患者BMI采用个体化管电压结合高权重ASIR-V可在满足CTC图像质量和诊断需求的同时,显著降低辐射剂量。Objective To explore the feasibility of ultra-low dose CT colonography based on BMI with individualized tube voltage and high-weight ASIR-V.Methods 90 patients(aged from 31 to 81 years,54 males and 36 females)who underwent CT colonography were collected.According to the clinical diagnostic requirements of CTC,patients were scanned in the supine position and the prone position.In the supine position(group A),different tube voltages were selected according to BMI and divided into three groups(30 cases in each group):A1(<23 kg/m^(2)):70 kVp,A2(23-25 kg/m^(2)):80 kVp,A3(>25 kg/m^(2)):100kVp,images were reconstructed with 80%ASIR-V standard algorithm.Conventional low dose scanning was used in the prone position(group B,corresponding to group A:B1,B2,B3),tube voltage was 120 kVp,images were reconstructed with 30%ASIR-V standard algorithm,other scanning parameters were the same as group A.The volume CT dose index(CTDIvol)and dose length product(DLP)were recorded.The CT values and SD values(noise)of psoas major muscle and colon air were measured at AW4.7 workstation,and signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were calculated.Two radiologists were blinded to assess the reconstructed image quality of CT colonography.The consistency of scores,radiationdose,subjective image quality and objective image quality were compared.Results The SD value in group A was lower than that in group B(P<0.05).The CT value,SNR and CNR in group A were higher than those in group B(P<0.05).Inter-observer agreement for subjective image quality score was good with kappa value of 0.613-0.930.There was no statistical difference in the subjective image quality scores(P>0.05),and both of which maintained the diagnostic requirements.DLP(mGy·cm)of groups A1-A3 were 75.85±9.75,152.12±19.58 and 245.00±67.04,respectively.Compared with groups B1,B2 and B3,DLP of groups A1,A2 and A3 decreased by 64.5%,48.3%and 33.4%.Conclusion BMI-based CT colonography with individualized tube voltage and high-weight ASIR-V can remarkably reduce radiati

关 键 词：CT结肠造影 个体化管电压 体重指数 迭代重组算法 辐射剂量 

分 类 号：R816.5[医药卫生—放射医学]