摘要
目的 探讨能谱CT显示肺癌患者不典型成骨性转移病灶的图像质量及最佳单能量水平.方法 回顾性分析经病理证实为肺癌,且行胸部和（或）腹部能谱CT检查≥2次,在最后1次检查中病灶明显增大或密度增高,结合CT随访、活检、骨扫描或PET CT检查等确诊为骨转移瘤,而在第1次检查中由于病灶不典型而漏诊及呈可疑异常密度改变的病灶.22例肺癌患者的72个病灶纳入研究.患者均行能谱CT检查,获得混合能量图像（140 kVp）和单能量图像（40、50、60、70、80、90、100、110、120、130、140 keV）.由2名影像科医师盲法分析第1次能谱CT扫描图像,并测量140 kVp图像和各单能量图像病灶的信噪比（SNR）和病灶与背景的对比噪声比（CNR）,并对病灶显示的明显程度进行评分.各单能量图像和140 kVp图像SNR、CNR的比较采用配对样本t检验,2名观察者评分间的一致性采用Kappa值分析,各单能量图像和140 kVp图像评分的比较采用配对设计秩和检验.结果 140 kVp图像的SNR为48.03±20.17,50、60和70 keV图像的SNR分别为58.52±22.92、64.07±24.88、59.54±22.04,均高于140 kVp图像的SNR,差异均有统计学意义（t值分别为13.366、16.278和18.889,P均＜0.01）,其中60 keV图像的SNR最高.140 kVp图像的CNR为7.64±4.52,50、60、70和80 keV图像的CNR分别为7.95±4.99、8.12±5.08、8.16±5.05、7.89±4.81,均高于140 kVp图像的CNR,差异均有统计学意义（t值分别为3.519、5.050、6.231和4.413,P均＜0.01）,其中60、70 keV图像的CNR高于50、80 keV图像的CNR.2名医师对病灶的评分一致性好（Kappa=0.864,P＜0.05）.2名医师60 keV图像的评分均高于140 kVp图像,并高于其他单能量图像.结论 能谱CT单能量成像对于肺癌不典型成骨性转移病灶的显示优于混合能量CT,60 keV为显示病灶的最佳单能量水平.
Objective To assess image quality and optimal keV levels of spectral CT virtual monochromatic series in atypical vertebral osteoblastic metastases of lung cancer.Methods Patients with pathologically proven lung cancer who had undergone spectral CT （Discovery CT750 HD,GE） of the chest or abdomen more than twice were analyzed retrospectively.Vertebral osteoblastic metastases were confirmed by follow-up CT examinations,biopsy,emission CT,PET/CT.The bone lesions were missed due to atypicalappearance or presented with suspicious density at the first exmaination were chosen.A total of twenty two patients with 72 lesions were enrolled.Conventional polychromatic images （140 kVp） and monochromatic images were generated （40 to 140 keV at an interval of 10 keV）.The signal to noise ratio （SNR） and contrast to noise ratio （CNR） of the lesions were measured and calculated at all the 12 series images by two radiologists.The two radiologists scored the different series of images independently.Paired sample t test was used to compare SNR and CNR among 40 to 140 keV and 140 kVp images.The inter-observer agreement between the two radiologists was evaluated using Kappa statistics and the difference of different images intrarobserver was compared using Wilcoxon signed rank test.Results The SNR of 140 kVp was 48.03±20.17,and those of 50,60 70 keV images were 58.52±22.92,64.07±24.88,59.54±22.04.SNR of 50,60,70 keV images was higher than that of 140 kVp （t values were 13.366,16.278,18.889,P＜0.01）,60 keV images had the highest SNR.The CNR of 140 kVp was 7.64±4.52 and those of 50,60,70 and 80 keV images were 7.95±4.99,8.12±5.08,8.16±5.05,7.89±4.81.CNR of 50,60,70 and 80 keV images were higher than that of 140 kVp image （t values were 3.519,5.050,6.231,4.413,P＜0.01）,60 keV and 70 keV images had the higher CNR than 50 keV and 80 keV.Good interobserver agreement was found for the evaluation of image quality （Kappa =0.864,P＜0.05）.Moreover,the scores of both the two observes for 60 keV images were higher than 140 kVp images and higher than other monochromatic images.Conclusion Atypical vertebral osteoblastic metastases of lung cancer are more conspicuous in virtual monochromatic images as compared wtih 140 kVp polychromatic images and the optimal energy level was 60 keV,repectively.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2015年第3期164-167,共4页
Chinese Journal of Radiology
基金
大连科技局2013科学计划项目（2013E15SF165）
关键词
肺肿瘤
骨肿瘤
肿瘤转移
体层摄影术
X线计算机
Lung neoplasms
Bone neoplasms
Neoplasm metastasis
Tomography, X-ray computed
