能谱CT心肌灌注图像质量的优化  

Imaging quality optimization of myocardial perfusion with spectral CT

作　　者：马帅[1,2] 邵广瑞[2] 李朝华[2] 赵永[2] 纪宇[1,2] 

机构地区：[1]山东大学医学院,山东济南250012 [2]山东大学第二医院影像科,山东济南250033

出　　处：《医学影像学杂志》2016年第4期612-616,629,共6页Journal of Medical Imaging

摘　　要：目的探讨能谱CT单能量成像与自适应统计迭代重建（adaptive statistical reconstruction,ASiR）心肌灌注的最佳扫描参数组合。方法对30例疑诊冠心病患者行心脏能谱扫描,对原始图像分别采用多组单能量联合不同权重ASiR技术以及传统混合能量模式重建并对特定心肌节段的噪声、信噪比（signal-to-noise ratio,SNR）、对比噪声比（contrast-to-noise ratio,CNR）及线束硬化伪影（beam-hardening artifacts,BHA）进行单因素方差分析。结果与传统混合能量成像相比,较高单能量可降低图像噪声和BHA,40%及以上ASiR重建可增强降噪效果,对伪影改善并不显著;75ke V对应的SNR（48%;P〈0.001;联合80%ASiR）和CNR（35%;P〈0.001;联合60%ASiR）有最大优化。结论与混合能量成像相比,70~75ke V单能量联合40%ASiR重建可显著降低心肌灌注图像噪声、改善伪影并提高SNR、CNR。Objective To explore the optimum match of monochromatic energy level and adaptive statistical reconstruction（ ASiR） for monochromatic reconstruction of myocardial CT perfusion（ CTP） images with dual-energy CT. Methods Thirty subjects with suspected coronary artery disease（ CAD） were scanned on spectral CT,conventional polychromatic images and 10 sets of monochromatic images（ 60,65,70,75,80,90,100,110,120,and 130 kiloelectron volts（ ke V）; each with increasing contributions of ASiR,ie,0%,20%,40%,60%,80%） was obtained from a single gemstone spectral imaging（ GSI） acquisition. The background noise,signal-to-noise ratio（ SNR）,contrast-to-noise ratio（ CNR） and beam-hardening artifacts（ BHA） of the specific myocardial segment in monochromatic images were assessed by ANOVA test and were compared with conventional polychromatic groups. Results With the increase of monochromatic energy imaging noise,BHA decreased,reaching the noise＇s nadir at 75 ke V level. Adding 40% or more ASiR contributed to the reduction of the noise,while for BHA,this seemed ambiguous. Compared with conventional polychromatic images,reconstructions with 75 ke V showed the highest improvement in SNR（ 48%,P〈0. 001,combined with 80% ASiR） and CNR（ 35%,P〈0. 001,combined with 60% ASiR）. Conclusion Monochromatic reconstruction at 70 ~ 75 ke V combined with 40% ASiR can offer satisfactory reduction of noise and BHA,meanwhile,obtains superior SNR and CNR in this myocardial CTP scan with spectral CT.

关 键 词：心肌灌注 宝石能谱成像 迭代重建算法 体层摄影术 X线计算机 

分 类 号：R542.2[医药卫生—心血管疾病] R814.42[医药卫生—内科学]