CT能谱单能量成像用于提高脑血管CTA成像质量

目的探讨CT能谱单能量图像对提高脑血管CTA成像质量的价值。方法回顾性分析53例接受脑血管能谱CTA检查的患者,获得5组单能量图像(50、70、90、110、130keV)、1组质量控制(QC)图像。分别测定6组图像的噪声、CNR,并对图像质量进行评分。采用单因素方差分析比较6组图像的CNR及噪声差异,组间两两比较采用LSD-t检验;采用多组独立样本秩和检验(Kruskal-Wallis H)比较图像质量评分差异。结果 6组中,70keV组与90keV组图像噪声差异无统计学意义(P0.05),其余各组间两两比较差异均有统计学意义(P均0.05);6组图像CNR、图像质量评分两两比较差异均有统计学意义(P均0.05),50keV单能量图CNR、图像质量评分均最高,70keV单能量图、QC图及90、110、130keV单能量图的CNR、图像评分均依次递减。结论能谱CT 50keV单能量图像能显著提高脑血管CTA的图像质量,值得临床推广应用。

Spectral CT monochromatic imaging in improving the image quality of head CT angiography

Objective To explore the value of spectral CT monochromatic imaging in improving the image quality of head CTA.Methods A total of 53 patients underwent head CTA with spectral CT monochromatic technique were analyzed retrospectively,five groups of monochromatic images（50,70,90,110,130keV）and one group of quality control（QC）images were acquired.The image noise and CNR in each group was measured respectively,and the score of image quality was also assessed and compared.The differences of image noise and CNR in the six groups were measured by one-way analysis of variance and multiple comparisons,The differences of image quality were compared by Kruskal-Wallis H.ResultsThe difference of image noise was not statistically significant（P〈0.05）between 70 keV and 90 keV monochromatic imaging,while the remaining pairs were statistically significant（all P〈0.05）.The differences of CNR and image quality among the six groups were statistically significant（all P 0.05）,the CNR and image quality were top rated in 50 keV monochromatic imaging,but successively descended in 70 keV imaging,QC imaging,90 keV,110keV,130 keV imaging.Conclusion Spectral CT monochromatic imaging at 50 keV level for head CTA can notably improve the overall image quality and is worth widely using in clinical work.