双源CT单能谱成像技术在胸部内固定术后使用优化方案  

The optimum programme of monoenergetic imaging technology of dual-source CT for chest trauma fixed with metal fixator

作　　者：王栋 刘斌[1] 

机构地区：[1]安徽医科大学第一附属医院放射科,安徽合肥230022 [2]安庆市立医院CT室,安徽安庆246000

出　　处：《实用放射学杂志》2018年第1期121-125,共5页Journal of Practical Radiology

摘　　要：目的 探讨胸部外伤骨折金属内固定术后使用双源CT单能谱成像技术的优化方案.方法 选取50例胸部内固定术后的受检者作为研究对象,随机分为5组,每组10例,行双源CT双能量扫描,其中A组使用平卧位＋实时动态曝光剂量调节（CARE Dose4D）＋管电压80/SN 140 kV检查,B组使用平卧位＋80/SN 140 kV检查,C组使用平卧位＋CARE Dose4D＋100/SN 140 kV检查,D组使用平卧位＋CARE Dose4D＋140/80 kV检查,E组使用半卧位＋CARE Dose4D＋ 80/SN 140 kV检查,比较5组间的CT容积剂量指数（CTDIvol）、剂量长度乘积（DLP）、有效剂量（ED）.每个受检者随机选取3个固定钉,对采集的数据进行单能谱曲线分析,获取最小CT差值能量点,计算此时固定钉最大低密度伪影面积（S,cm2）、图像整体对比信噪比（CNR）.并对图像质量行4分法主观评分.结果 E组的CTDIvol、DLP及ED明显低于B、C、D 3组,略低于A组;E组图像质量及S较A、B、C、D组更优, CNR与A、B、C组无差异,优于D组.结论 患者采用半卧位,使用CARE Dose4D技术结合80/SN 140 kV的管电压组合,后处理时利用能谱曲线快速确定最佳能量点,可以个性化地获取最佳去胸部金属内固定伪影图像并降低辐射剂量.Objective To study the optimum programme of monoenergetic imaging technology of dual-source CT in visualization for patients with chest trauma and fractures fixed with metal fixator.Methods Fifty patients with fractures by chest trauma fixed with metal fixator were selected as research subjects.Subjects were divided into 5 groups randomly,10 in each group.Each group underwent dual-source CT scanning：Group A,supine position＋CARE Dose4D＋80/SN 140 kV check;Group B,supine position＋80/SN 140 kV check;Group C,supine position＋ CARE Dose4D＋100/SN 140 kV check;Group D,supine position＋ CARE Dose4D＋ 140/80 kV check;Group E,semireclining position＋CARE Dose4D＋80/SN 140kV check.The volume CT dose index（CTDIvol）,dose length product（DLP）and effective dose（ED）of each group were compared.Three fixators were selected from each patient randomly.Then the monoenergetic curve analysis was carried out on the acquisition data to obtain the minimum CT differential energy points,and meanwhile the biggest area of low density artifacts（S,cm2）of the fixators and the contrast to noise ratio（CNR）of overall image were calculated.The quality of images was subjectively graded by a 4-score scale.Results The CTDIvol,DLP and ED were signifi-cantly lower in group E than that in group B,C and D,and slightly lower than that in group A.The quality of images and the area of low density artifacts（S）in group E were better than that in group A,B,C,and D.There were no differences in CNR between group E and group A,B and C,but better than that in group D.Conclusion The use of semireclining position,CARE Dose4D,combined with 80/SN 140 kV tube voltage.And then the use of analyzation of monoenergetic curves to define the optimum monoenergetic point rapidly when reprocess,allow for significant dose reduction and the best personalized image for chest trauma fixed with metal fixator.

关 键 词：计算机体层成像 单能谱技术 金属伪影 图像质量 辐射剂量 

分 类 号：R814.42[医药卫生—影像医学与核医学] R816.4[医药卫生—放射医学]