CT单能量成像在肝图像质量和诊断中的价值

Value of Spectral CT Monochromatic Imaging on the Image Quality and Diagnosis of Liver Disease

目的:探讨能谱CT单能量成像对肝脏图像质量和诊断的影响。方法:对80例肝脏病变患者采用能谱成像模式扫描,获得常规混合能量图像和能量为50keV和70keV的单能量图像,对三组图像质量进行主观评分、测量肝脏病灶的CNR和图像噪声,同时对基于图像的诊断可靠性进行评级,统计方法分别采用配对t检验和Wilcoxon秩和检验。结果:70keV单能量图像的主观评分较常规混合能量图像增高,肝脏病灶的CNR增高而图像噪声降低,两者间各项指标的差异均具有统计学意义。50keV组的图像噪声相比较高,但70keV联合50keV图像的应用,基于图像的诊断可靠性要高于混合能量图像,差异具有统计学意义。结论:单能量图像能够通过70keV较高水平单能量图像显著提高肝脏图像质量,同时联合50keV较低能量水平图像的应用有利于肝脏病灶的检出。

Purpose： To evaluate the effect of spectral CT monochromatic imaging on the image quality and diagnostic confidence of liver disease. Methods： Spectral CT imaging was performed in 80 patients with hepatic lesions to obtained the conventional polychromatic images, 50keV and 70keV monochromatic images. The image quality, CNR of hepatic lesion and the image noise were measured and analyzed, and the confidence level of diagnosis was recorded. Student t test and Wilcoxon rank sum test were used for statistical analysis. Results： The image quality of 70keV monochromatic images was higher than that of the conventional polychromatic images, the CNR of hepatic lesions was increased but the image noise was decreased, the difference was with statistical significant. And when combined with 50keV images, the diagnostic confidence level was higher. Conclusion： The hepatic image quality is improved when spectral CT monochromatic images at 70keV is used, and the diagnostic confidence can be obviously improved when 50keV monochromatic images is combined, which is helpful for the detection of hepatic lesions.