双能量CT冠状动脉和心肌成像的优化对比噪声比研究  

Dual-Energy CT Imaging of Coronary Arteries and Myocardium for Optimal Contrast-to-noise Ratio

作　　者：王怡宁[1] 金征宇[1] 孔令燕[1] 张竹花[1] 牟文斌[1] 王沄[1] 张云庆[1] 

机构地区：[1]中国医学科学院北京协和医院放射科,北京100730

出　　处：《中国医学影像学杂志》2010年第5期449-453,共5页Chinese Journal of Medical Imaging

摘　　要：目的:探讨应用专门软件优化双能量CT冠状动脉和心肌成像的对比噪声比的价值。材料和方法:36例可疑或已知冠心病患者接受了双源CT双能量心脏增强扫描,得到4个重建序列,序列A源自管球A;序列B源自管球B;序列C中70%的数据源自管球A,30%的数据源自管球B;序列D是依据特殊算法在每个像素点上取不同比例的序列A和序列B成分而得到。比较A、B、C、D4组主动脉根部和左室心肌的平均CT值及标准差以及图像的平均对比噪声比。结果:B组和D组的主动脉根部平均CT值最高,分别为(552.3±74.7)Hu和(551.5±73.2)Hu,与A组和C组的差异有显著性(P<0.05)。B组左室心肌CT值的平均标准差(31.9±7.4Hu)最高,与其他3组的差异有显著性(P<0.05),而其他3组间的差异无显著性(P>0.05)。D组的平均对比噪声比(19.8±5.6)最高,与其他3组两两比较差异有显著性(P<0.05)。结论:双能量CT心脏扫描结合专门软件既可以保留图像强化效果又可以获得低噪声,优化了对冠状动脉和心肌成像的对比噪声比。Purpose To assess the value of a dedicated software for improving the contrast-to-noise ratio（CNR）of dual-energy CT（DECT）imaging of the heart.Materials and Methods Thirty-six patients with suspected or known coronary artery disease underwent contrast-enhanced DECT coronary angiography using dual-source CT.The dataset reconstructed from the rawdata of tube A or tube B was defined as A or B data,respectively.A weighted Hu-value of 70% of A and 30% of B data for general viewing of coronary arteries results in C data.Weighting of A and B data chosen pixel by pixel with dedicated software results in D data.The attenuation was measured at the root of ascending aorta and lateral wall of left ventricle for all data.Noise was measured in standard deviation（SD）of the CT value in the lateral wall of left ventricle.Differences of mean attenuation and noise were evaluated.Results The mean attenuation achieved at the ascending aorta was found higher in group B（552.3±74.7 Hu）and D（551.5±73.2 Hu）than in group A（369.8±46.2 Hu）and C（426.0±58.5 Hu）,all P〈0.05.Noise at the lateral wall of the left ventricle was found higher in group B（31.9±7.4 Hu）than in group A（22.4±4.8 Hu）,C（21.9±6.1 Hu）,and D（23.6±6.3 Hu）,all P〈0.05,with no significant differences of the latter three（all P〉0.05）.The CNR was found higher in group D（19.8±5.6）than in group A（12.8±3.5）,B（13.8±3.8）,and C（15.6±4.8）,all P〈0.05.Conclusion With dedicated software it is possible for DECT to conserve the contrast enhancement of low kV images and low noise of high kV images to achieve superior CNR for imaging the coronary arteries and the myocardium.

关 键 词：体层摄影术 X线计算机 冠状血管造影术 放射摄影术 双能扫描投影 

分 类 号：R543.310.454[医药卫生—心血管疾病]