论文部分内容阅读
目的:探讨双层探测器光谱CT单能量成像联合个性化对比剂注射方案在颅脑CT血管成像（CTA）中的应用价值。方法:回顾性分析2020年8月至11月在华中科技大学同济医学院附属协和医院采用双层探测器光谱CT和个性化对比剂注射方案行颅脑CTA检查的76例患者的影像资料。对基于双层探测器光谱CT数据重建生成的120 kVp混合迭代传统能量图（常规组）与50 keV光谱虚拟单能量图（试验组）进行图像质量的客观和主观评价，客观评价内容包括颈内动脉及大脑中动脉处的CT值、信噪比（SNR）和对比噪声比（CNR）、脑实质的CT值和标准差。主观评价由2名高年资影像医师按照5分法完成，2名医师主观评分的一致性采用Kappa检验。采用配对样本n t检验或Wilcoxon秩检验进行组间分析。n 结果:试验组颈内动脉、大脑中动脉及脑实质的CT值、SNR和CNR均较常规组高，差异有统计学意义（n P均<0.001）。2名医师对试验组的主观评分均为5（5，5）分，对常规组的主观评分均为4（4，4）分，医师间主观评分一致性较好，Kappa值分别为0.74和0.84。试验组主观评分高于常规组，差异有统计学意义（n Z=-11.15，n P<0.001）。n 结论:在颅脑CTA检查中，使用双层探测器光谱CT单能量成像联合个性化对比剂注射方案，能够显著提高SNR和CNR，优化图像质量。“,”Objective:To explore the value of monoenergetic imaging on dual-layer spectral detector CT combined with individual injection protocol of contrast medium in brain CT angiography (CTA).Methods:Seventy-six patients who underwent brain CTA on the Philips IQon dual-layer spectral detector CT and individual injection protocol of contrast medium in Union Hospital of Tongji Medical College, Huazhong University of Science and Technology from August to November 2020 were retrospectively analyzed. Objective and subjective evaluation of image quality was performed in conventional energetic images (conventional group) which derived from 120 kVp hybrid iterative reconstruction algorithm and 50 keV virtual monoenergetic images (test group) which derived from spectral reconstruction algorithm. The objective evaluation content included CT values, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of internal carotid artery and middle cerebral artery, CT values and standard deviation (SD) of brain parenchyma. The subjective evaluation was completed by two senior radiologists according to the 5-point scale, and the inter-agreement between two radiologists was evaluated by Kappa test. Paired n t test or Wilcoxon rank test was used for analysis between two groups.n Results:The SNR and CNR of both internal carotid artery and middle cerebral artery, as well as CT values of internal carotid artery, middle cerebral artery and brain parenchyma, were significantly higher in test group than that in conventional group (all n P<0.001). The subjective scores of two radiologists for test group were both 5 (5, 5) points, and the subjective scores for conventional group were both 4 (4, 4) points. The subjective scores of the radiologists were in good agreement, and the Kappa values were 0.74 and 0.84 respectively. The subjective scores of test group were significantly higher than that of conventional group (n Z=-11.15, n P<0.001).n Conclusion:Monoenergetic imaging on dual-layer spectral detector CT combined with individual injection protocol of contrast medium can improve SNR, CNR and the image quality of brain CTA.