摘要
目的:探讨双能CT小肠成像单能量图像显示正常回肠壁的成像质量及其与混合能量图像在小肠CT成像中的差异。方法:对18例拟诊为炎症性肠病患者行小肠CT成像(CTE),采用双能CT宝石能谱成像技术行CT平扫及双期增强扫描(实质期和延迟期),将实质期图像数据分别进行混合能量和GSI单能量重建,应用能谱分析软件,获得正常回肠壁最佳对比噪声比(CNR)单能图像的KeV值。计算混合能量和单能图像上正常回肠壁的对比噪声比,测量两种图像的噪声并进行配对t检验;由两位医师对两种图像上主动脉锐利度、噪声和图像质量进行主观评分并进行配对t检验,计算组内相关系数来评价观察者间的一致性。结果:正常回肠壁最佳CNR单能量为(56.67±5.04)KeV;单能图像正常回肠壁的CNR高于混合能量(分别为4.36±0.71和3.34±0.78,t=4.702,P<0.01),脂肪组织的图像噪声高于混合能量图像(分别为16.87±2.73和14.58±2.26,t=3.85,P<0.01),液体区域的噪声也高于混合能量图像(分别为16.08±4.17和13.51±2.85,t=4.96,P<0.01);混合能量和单能图像的锐利度评分分别为3.08±0.50和2.97±0.38、图像质量评分分别为2.92±0.28和2.94±0.23,差异均无显著性意义(P=0.32,P=0.66),单能图像噪声评分低于混合能量(分别为2.36±0.49和2.75±0.44,t=3.62,P<0.01);两位医师评价单能图像质量和混合能量图像噪声的一致性好(r分别为1.00和0.42)。结论:双能CT最佳CNR单能图像评价正常回肠壁有较好的对比噪声比和成像质量。
Objective：To evaluate the image quality of CT enterography（CTE） with monochromatic images of dual energy CT.Methods：Eighteen patients underwent CT enterography with dual energy CT（Gemstone spectral imaging,GSI） examinations.The spectrum analysis was used to select the monochromatic images for obtaining the best contrast-to-noise ratio（CNR） for ileum wall.The CNR and image noise of ileum wall at the selected monochromatic level and the conven-tional polychromatic images were measured.Two readers assessed the image quality,noise and sharpness of both optimal CNR monochromatic level and the conventional polychromatic images.Results：At the selected monochromatic level,the image noise of monochromatic images was higher than that of polychromatic images（fat：16.87±2.73 vs 14.58±2.26,t=3.85,P0.01;fluid：16.08±4.17 vs 13.51±2.85,t=4.96,P0.01）.The CNR of ileum wall in monochromatic images was also higher than that of polychromatic images（4.36±0.71 vs 3.34±0.78,t=4.702,P0.01）.The intraclass correlation coefficient values among readers for optimal CNR monochromatic images quality was 1.00.Conclusion：Monochromatic images at optimal CNR keV for CTE can improve CNR for normal ileum wall and improve the overall image quality of CTE.
出处
《放射学实践》
2012年第3期254-258,共5页
Radiologic Practice
