摘要
目的评价能谱CT不同虚拟单能量成像（VMS）对冠状动脉运动追踪冻结技术（SSF）改善冠状动脉搏动伪影的作用。方法连续搜集29例临床疑诊冠心病患者行冠状动脉CT造影检查。在70 keV条件下,以5%R-R间期为间隔重组图像,每个心动周期分布重建出使用SSF和不使用SSF（STD）的两组图像进行对比,选择出SSF改善搏动伪影最明显的心动期相（5分法评价标准）;然后在这个心动期相内重建出SSF联合VMS（40~100 keV,10keV间隔）的图像。比较70 keV联合STD图像和7组VMS联合SSF图像间搏动伪影主观评分,测量并比较7组VMS图像主动脉根部的平均CT值。结果本组受检者平均心率（60. 66±6. 14） bpm（47~76 bpm）。低能量VMS图像主动脉内CT值较高,过低VMS（40 keV）或过高VMS（90~100 keV）不利于SSF纠正冠状动脉运动所造成的伪影,50~80 ke V图像的图像质量分数高于40 keV和90、100 keV（P 〈0. 05）,90、100 keV时血管内CT值低,SSF不能很好纠正冠状动脉运动所造成的伪影。结论冠状动脉内CT值可能是影响SSF改善冠状动脉搏动伪影的重要因素,通过改变虚拟单能量水平可调整冠状动脉内过高或过低CT值,进而有利于SSF发挥作用。
Objective To investigate the effect of motion correction by Snap Shot freeze technique in coronary CT angiography obtained at virtual monochromatic spectral images. Methods 29 cases suspected of coronary artery disease were underwent dual-energy spectral CCTA. Images were reconstructed without（ standard algorithm,STD） and with SSF at cardiac phases between 55 % and 85 % of the R-R interval in each patient. Comparisons were made between each image reconstructed with and without SSF. Selected the cardiac phase with the most improved per-vessel image quality（ 5 scale） and then reconstruct VMS（ 40-100 keV,with 10 keV interval） combined with SSF images. Compared STD images at 70 keV and VMS images with SSF on per-vessel image quality scores. Used the one-way ANOVA to compare the CT value of the aortic root for each VMS. Results The average patient heart rates were（ 60. 66 ± 6. 14） bpm（ 47-76 bpm）. Low energy VMS images improved CT value compared with higher energy VMS images. The image quality scores for images at 50-80 keV were higher than those of 40 keV and 90,100 keV（ P〈0. 05） because of the CT value intra-coronary were too high or too low,especially 90 and 100 keV for the low contrast agent density. Conclusion SSF can effectively reduce the motion artifacts when intra-coronary has a suitable contrast agent CT value,a suitable CT value may be a prerequisite for SSF to play the role,VMS can adjust the inappropriate CT value,and is helpful for motion artifact correction by SSF.
作者
贾永军
于楠
贺太平
于勇
段海峰
杨创勃
JIA Yongjun;YU Nan;HE Taiping(Department of Radiology,Affiliated Hospital of Shaanxi Chinese Medicine University,Xianyang,Shaanxi Province 712000,P.R.China)
出处
《临床放射学杂志》
CSCD
北大核心
2018年第10期1760-1764,共5页
Journal of Clinical Radiology
