| 摘要: |
| ［摘要］ 目的 比较全模型迭代重建(IMR)算法与混合迭代重建（iDose4）算法对低剂量左房肺静脉CT图像质量的影响。方法 招募2020年1月至12月因房颤于广西医科大学第二附属医院行射频消融术的患者30例，均接受低剂量左房肺静脉CT检查，管电压80 kV，管电流350 mA，扫描结束后采用IMR算法（IMR组）和iDose4算法（iDose4组）重建图像，对两组图像质量进行主观评分。于右上肺静脉（RSPV）、右下肺静脉(RIPV)、左上肺静脉(LSPV)、左下肺静脉(LIPV)开口处勾画感兴趣区（ROI），于左心房中心层面对左心房、降主动脉及胸壁脂肪勾画ROI。ROI选择密度均匀处勾画，记录各ROI内CT值和噪声值（SD值），计算左心房、RSPV、RIPV、LSPV、LIPV的对比噪声比（CNR）和信噪比（SNR），对比两组图像的客观评分。结果 两名放射科医师对IMR组和iDose4组图像的主观评价一致性高，组间相关系数（ICC）分别为0.895（P<0.001）、0.920（P<0.001）。IMR组图像质量主观评分显著高于iDose4组［（4.50±0.57）分 vs （3.86±0.68）分；t=3.898，P<0.001］。IMR组左心房、RSPV、RIPV、LSPV、LIPV的图像噪声值（SD值）低于iDose4组，SNR和CNR高于iDose4组，差异有统计学意义（P<0.05）。IMR组左心房、RSPV、RIPV、LSPV、LIPV的CT值低于iDose4组，差异有统计学意义（P<0.05）。结论 相较于iDose4算法，IMR算法可显著降低低剂量左房肺静脉CT图像的噪声，提高SNR和CNR，从而提高图像质量，值得在临床中推广。 |
| 关键词: 左房肺静脉CT 全模型迭代重建算法 混合迭代重建算法 图像质量 |
| DOI：10.3969/j.issn.1674-3806.2024.10.14 |
| 分类号:R 445.3 |
| 基金项目:广西医科大学第二附属医院院级科研项目（编号：EFYKY2020009）；广西卫生健康委西医类别自筹经费科研课题（编号：Z20210551） |
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| Comparative study on the effects of IMR algorithm and iDose4 algorithm on the image quality of low-dose left atrial pulmonary vein CT |
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DU Guoxiang, LIANG Zhimei, LI Min, LUO Yingyi, LU Bingfeng, LI Weixiong
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Department of Radiology, the Second Affiliated Hospital of Guangxi Medical University, Nanning 530007, China
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| Abstract: |
| ［Abstract］ Objective To compare the effects of iterative model reconstruction(IMR) algorithm and hybrid iterative reconstruction(iDose4) algorithm on the image quality of low-dose left atrial pulmonary vein CT. Methods A total of 30 patients undergoing radiofrequency ablation due to atrial fibrillation in the Second Affiliated Hospital of Guangxi Medical University from January 2020 to December 2020 were recruited. The recruited patients received low-dose left atrial pulmonary vein CT examination with tube voltage of 80 kV and tube current of 350 mA. After scanning, the images were reconstructed by using IMR algorithm(IMR group) and iDose4 algorithm(iDose4 group), and the image quality in the two groups was subjectively scored. The region of interest(ROI) was delineated at the opening of the right superior pulmonary vein(RSPV), the right inferior pulmonary vein(RIPV), the left superior pulmonary vein(LSPV) and the left inferior pulmonary vein(LIPV), and the ROI was delineated for the left atrium, descending aorta and chest wall fat at the central level of the left atrium. The areas with uniform density in the ROI were selected and delineated, and the CT value and noise value［standard deviation(SD) value］ in each ROI were recorded. The contrast-to-noise ratio(CNR) and signal-to-noise ratio(SNR) of the left atrium, RSPV, RIPV, LSPV and LIPV were calculated, and the objective scores were compared between the two groups. Results The subjective evaluations of the images in the IMR group and the iDose4 group by two radiologists were highly consistent, with intra-class correlation coefficient(ICC) being 0.895(P<0.001) and 0.920(P<0.001), respectively. The IMR group had significantly higher subjective scores of image quality than the iDose4 group［(4.50±0.57)points vs (3.86±0.68)points; t=3.898, P<0.001］. The image noise values(SD values) of the left atrium, RSPV, RIPV, LSPV and LIPV in the IMR group were lower than those in the iDose4 group, and the SNR and CNR in the IMR group were higher than those in the iDose4 group, and the differences were statistically significant(P<0.05). The CT values of the left atrium, RSPV, RIPV, LSPV and LIPV in the IMR group were lower than those in the iDose4 group, and the differences were statistically significant(P<0.05). Conclusion Compared with iDose4 algorithm, IMR algorithm can significantly reduce noise, improve SNR and CNR in low-dose left atrial pulmonary vein CT images, thereby improving the image quality. IMR algorithm is worth promoting in clinical application. |
| Key words: Left atrial pulmonary vein CT Iterative model reconstruction(IMR)algorithm Hybrid iterative reconstruction(iDose4) algorithm Image quality |
