摘要
目的探讨宽体探测器（80 mm）联合全模型实时迭代重建技术（ASIR-V）在上腹部增强扫描中降低辐射剂量和提高图像质量的价值。方法根据体模实验探寻宽体探测器联合ASIR-V扫描辐射剂量较常规探测器（40 mm）减半时ASIR-V所在百分比。在体模实验基础上，前瞻性收集行上腹部CT增强扫描的160例患者，按随机数字表分成实验组（120例）和对照组（40例）。对照组（A组）采用常规探测器CT扫描，后期40%ASIR重建；实验组B、C、D组（各40例）分别采用0、20%、40%前置ASIR-V扫描，B组行0～100%后置ASIR-V重建（间隔10%）获得B0～B10亚组；C、D组分别行20%～60%、40%～60%后置ASIR-V（间隔20%）重建获得C1～C3、D1～D2亚组。测量图像噪声值，肝脏、胰腺、大血管的CT值，计算对比噪声比（CNR），并对图像进行主观评分。采用单因素方差分析、t检验、Mann-Whitney U、Kruskal-Wallis H法进行统计学分析。结果体模实验中，宽体探测器联合40%前置ASIR-V时辐射剂量较常规探测器减半。临床实验中，D组辐射剂量较A组降低35.5%。B2～B10、C2～C3、D1～D2亚组噪声低于A组（t＝－14.681～－3.046，均P〈0.05），C2、D2亚组除肝脏动脉期CNR及D1亚组除肝脏、胰腺动脉期CNR与A组无差异外（t＝0.574～1.327，均P〉0.05），余部位及B4～B10、C3亚组各部位CNR值均高于A组（t＝2.048～9.248，均P〈0.05）。B0～B6亚组内图像主观评分渐高，B7～B10亚组图像主观评分渐低，B3～B8、C2～C3、D1～D2主观评分高于A组（Z＝－2.229～－6.533，均P〈0.05）。结论宽体探测器联合40%前置ASIR-V、后期60%后置ASIR-V重建可明显降低辐射剂量并获得较好的图像质量。
ObjectiveTo investigate the image quality and radiation dose with wide-detector（80 mm） and adaptive statistical iterative reconstruction-V （ASIR-V） technique at abdominal contrast enhanced CT scan.MethodsIn the first phantom experiment part, the percentage of ASIR-V for half dose of combined wide detector with ASIR-V technique as compared with standard-detector （40 mm） technique was determined. The human experiment was performed based on the phantom study, 160 patients underwent contrast-enhanced abdominal CT scan were prospectively collected and divided into the control group （n=40） with image reconstruction using 40% ASIR （group A） and the study group （n=120） with random number table. According to pre-ASIR-V percentage, the study group was assigned into three groups[40 cases in each group, group B： 0 pre-ASIR-V scan with image reconstruction of 0-100% post-ASIR-V （interval 10%, subgroups B0-B10）; group C： 20% pre-ASIR-V with 20%, 40% and 60% post-ASIR-V （subgroups C1-C3）; group D： 40%pre-ASIR-V with 40% and 60% post-ASIR-V （subgroups D1-D2）]. Image noise, CT attenuation values and CNR of the liver, pancreas, aorta and portal vein were compared by using two sample t test and One-way ANOVA. Qualitative visual parameters （overall image quality as graded on a 5-point scale） was compared by Mann-Whitney U test and Kruskal-Wallis H test.ResultsThe phantom experiment showed that the percentage of pre-ASIR-V for half dose was 40%. With the 40% pre-ASIR-V, radiation dose in the study group was reduced by 35.5% as compared with the control group. Image noise in the subgroups of B2-B10, C2-C3 and D1-D2 were lower （t=-14.681--3.046, all P〈0.05） while CNR in the subgroups of B4-B10, C2-3 and D1-D2 were higher（t=2.048-9.248, all P〈0.05）than those in group A, except the CNR of liver in the arterial phase （AP） in C2, D1 and D2 and the CNR of pancreas in AP in D1 （t=0.574-1.327, all P〉0.05）. The subjective image quality scores increased gradually in the range o
出处
《中华医学杂志》
CAS
CSCD
北大核心
2017年第45期3567-3572,共6页
National Medical Journal of China
关键词
全模型实时迭代重建技术
宽体探测器
腹部
辐射剂量
图像质量
Adaptive statistiealiterativereeonstruction-V
Wide-detector
VAt^domen
Imagequality
Radiation dosage
