摘要
目的通过仿真胸部体模对比能谱扫描联用后置自适应统计迭代重建(ASiR-V)技术与常规扫描联用滤波反投影算法(FBP)的图像质量及辐射剂量,探讨胸部能谱CT成像应用于临床的可行性。资料与方法采用GE Revolution CT分别对仿真胸部体模进行能谱扫描和常规扫描,将所得能谱原始图像重建层厚5 mm的70 keV单能量图像。将70 keV单能量图像以10%递增,后重建ASiR-V权重为0%~100%的11组图像,0%即滤波反投影重建方法。测量每组图像的噪声值。分析各组图像噪声的差异,并采用双盲法对肺窗及纵隔窗进行主观图像质量评价。将70 keV单能量图像分别进行FBP重建(A1组)及最佳ASiRV权重重建(A2组),常规扫描进行FBP重建(B组)。比较各组图像噪声、图像质量主观评分和有效辐射剂量(ED)。结果图像噪声随后置ASiR-V权重的增加逐渐减低;ASiR-V为40%、50%、60%时,肺窗和纵隔窗的评分均为5分。A1、A2、B组的噪声值分别为7.617±2.480、5.108±1.558、7.483±2.890。A2组噪声值显著低于A1及B组,差异均有统计学意义(P<0.05);A1组与B组差异无统计学意义(P>0.05)。A1、A2、B组主观评分分别为4、5、3分。胸部能谱成像ED为6.84m Sv,常规扫描ED为6.77 m Sv。结论胸部CT检查中,能谱成像与常规扫描的射线剂量相当。能谱成像联合后置ASiR-V 40%~60%重建较常规扫描联合FBP重建可有效降低图像噪声,改善图像质量。
Purpose To study the image quality and radiation dose of chest simulation phantom by energy spectrum scanning combined with adaptive statistical iterative reconstruction V(ASiR-V) and conventional scanning combined with filtered back projection(FBP), so as to examine the feasibility of chest energy spectrum CT in clinic treatment. Materials and Methods Ge Revolution CT was used to carry out energy spectrum CT and conventional CT respectively on chest simulation phantom. The energy spectrum image obtained was reconstructed into a 70 keV monoenergetic image with a thickness of 5 mm, which was increased by 10% and then 11 ASiR-V images with weights of 0%-100% were reconstructed. Images with weights of 0% was reconstructed with filtered back projection algorithm. The noise value of each group of images was measured. The difference of image noise was analyzed, and the image quality of lung window and mediastinum window were subjectively evaluated by double-blind method. The 70 keV monoenergetic images were reconstructed through FBP(group A1) and optimal ASiR-V weight(group A2) respectively, and the images were reconstructed through FBP(group B) by conventional CT. The noise, image quality and effective radiation dose(ED) of each group were compared. Results The image noise was decreased with the increase of ASiR-V weight. When weight of ASIR-V was 40%, 50% and 60%, the lung window and mediastinum window were scored 5. The noise values of group A1, A2 and B were 7.617±2.480, 5.108±1.558, 7.483±2.890, respectively. The noise values in group A2 were significantly smaller than those in group A1 and group B with statistical significance(P<0.05). There was no statistical significance between group A1 and group B(P>0.05). Group A1, A2 and B were subjectively scored 4, 5 and 3, respectively. The ED values obtained by chest energy spectrum CT and conventional scanning were 6.84 mSv and 6.77 mSv, respectively. Conclusion ED of energy spectrum imaging is equivalent to that of conventional scanning. Compared with the conventional scanning combined with FBP reconstruction, energy spectrum scanning combine with reconstruction of ASiR-V 40%-60% can reduce the noise and improve the image quality.
作者
翟艳慧
艾娜娜
杨晨晓
王君鑫
李莹
张颖颖
贾守强
ZHAI Yanhui;AI Nana;YANG Chenxiao;WANG Junxin;LI Ying;ZHANG Yingying;JIA Shouqiang(Department of Imaging,Jinan City People’s Hospital,Jinan 271199,China)
出处
《中国医学影像学杂志》
CSCD
北大核心
2020年第3期201-204,209,共5页
Chinese Journal of Medical Imaging
基金
山东省保健科技协会科学技术项目(SDBJKT20180040)。
关键词
体层摄影术
X线计算机
胸部
迭代重建技术
辐射剂量
质量控制
人体模型
Tomography,X-ray computed
Thorax
Iterative reconstruction technique
Radiation dosage
Quality control
Manikins
