摘要
目的探讨能谱CT最佳单能量技术在肠系膜上动脉成像中降低对比剂用量和提升图像质量的可行性。方法收集我院肠系膜上动脉CTA受检者40例并随机分为A、B两组,A组采用能谱CT成像模式,对比剂用量450 mg I/kg,扫描后重组最佳单能量、40%ASIR图像;B组行常规120 kVp增强扫描,对比剂用量600 mg I/kg,扫描后重组40%ASIR图像。分别测量两组肠系膜上动脉及同层面右侧竖脊肌CT值及SD值,并计算肠系膜上动脉信噪比(SNR)和对比噪声比(CNR)。对两组图像分别进行容积再现(VR)、最大密度投影(MIP)、多平面重组(MPR)和曲面重组(CPR),由两名有经验医师采用5分法对图像质量进行主观评分。记录两组碘摄入量、容积CT剂量指数(CTDIvol)、剂量长度乘积(DLP),并计算有效辐射剂量(ED)。采用独立样本t检验和Mann-Whitney U检验进行统计学分析。结果两组一般资料和辐射剂量中CTDIvol、DLP、ED间差异无显著统计学意义(P>0.05)。A组对比剂碘摄入量[(25.47±3.43)g]较B组[(35.80±6.18)g]减少了约26.6%(P<0.05)。A组图像最佳单能量水平约65 keV。A组肠系膜上动脉的CT值、SNR、CNR均显著高于B组(P<0.05);A组、B组肠系膜上动脉SD值无显著统计学差异(P>0.05),但A组肠系膜上动脉SD值低于B组。两名医师主观评分一致性极好(Kappa值>0.80,P<0.05),A组图像主观评分(4.65±0.59)高于B组(3.86±0.57)(P<0.05)。结论在相似辐射剂量条件下,能谱CT最佳单能量(65 keV)成像可以显著降低肠系膜上动脉成像对比剂碘摄入量(约26.6%),且可获得优于常规120 kVp肠系膜上动脉成像的图像质量。
Objective To investigate the possibility of reducing contrast medium(CM)dose and improving image quality in superior mesenteric artery(SMA)imaging with optimal monochromatic energy of dual-energy spectral CT mode.Methods Forty patients undergoing contrast-enhanced abdominal CT were randomly divided into 2 groups.Patients in group A were scanned with spectral CT imaging mode,450 mg I/kg of CM,optimal monochromatic energy,and 40%ASIR reconstruction.Patients in group B underwent conventional CT at 120 kVp with 600 mg I/kg of CM,and 40%ASIR reconstruction.The CT densities and standard deviation(SD)values of SMA and erector muscle at the same level were measured,and the signal to noise ratio(SNR)as well as contrast to noise ratio(CNR)were calculated.The image quality was scored independently by two experienced radiologists using volume rendering,maximum intensity projection,multi-planar reconstruction and curved-planar reconstruction.The CM iodine intake,volume CT dose index(CTDIvol)and dose length product(DLP)were recorded and effective radiation dose(ED)was calculated.The independent sample t test and Mann-Whitney U test were used for statistical analysis.Results The general data,CTDIvol,DLP,ED between the two groups showed no significant difference(P>0.05).The CM iodine intake in group A[(25.47±3.43)g]was significantly(P<0.05)reduced by 26.6%compared with that in group B[(35.80±6.18)g].The CT densities,SNR,and CNR of SMA in group A were significantly higher than those in group B(P<0.05),whereas the SD values in group A were slightly lower than that in group B(P>0.05).The image quality scores of two radiologists showed good consistency(κ>0.80,P<0.05)with significantly(P<0.05)higher scores in group A(4.65±0.59)than that in group B(3.86±0.57).Conclusion At similar radiation dosage,the optimal monochromatic energy of dual-energy spectral CT mode can significantly reduce the CM iodine intake by 26.6%with better image quality than that of conventional 120 kVp enhanced CT of SMA.
作者
任占丽
雷雨欣
张敏
陈晓侠
张喜荣
贾永军
于楠
于勇
贺太平
REN Zhan-li;LEI Yu-xin;ZHANG Min;CHEN Xiao-xia;ZHANG Xi-rong;JIA Yong-jun;YU Nan;YU Yong;HE Tai-ping(Department of Medical Imaging,Affiliated Hospital of Shaanxi University of Chinese Medicine,Shaanxi 712000,China)
出处
《影像诊断与介入放射学》
2021年第1期15-19,共5页
Diagnostic Imaging & Interventional Radiology
基金
陕西中医药大学学科创新团队建设项目(2019-YS04)。
