IMR、iDose^(4)和FBP三种重建算法在隆鼻整形术CT扫描的应用研究

Application of IMR, iDose~4 and FBP Reconstruction Algorithms in CT Scanning of Rhinoplasty

目的:探讨IMR、iDose和FBP三种重建算法在肋软骨隆鼻术前胸部多排螺旋CT扫描中对图像质量的影响。方法:收集符合纳入标准的拟行自体肋软骨隆鼻术患者60例,术前均行胸部CT检查,分别使用IMR、iDose和FBP三种重建算法生成图像并进行相关后处理重建肋软骨,记录并比较各组图像质量主观评价分数和客观评价的指标如:肋软骨CT值、噪声、信噪比、对比噪声比。结果:三种算法得到的CT重建图像都能准确评估肋软骨钙化程度;主观评分IMR、iDose组与FBP组相比,在MIP图像上评分均值分别增加50.5%和33.6%,在VR图像上评分均值分别增加51.0%和19.0%。IMR组较iDose组的评分均值在MIP图像和VR图像上分别增加了11.1%和21.1%。客观评价肋软骨CT值、信噪比和对比噪声比并作统计学分析,最终显示IMR、iDose和FBP三种重建算法组间对比有显著差异,IMR组明显最优。结论:IMR、iDose和FBP三种重建算法均能准确评估自体肋软骨是否存在钙化及程度,IMR算法较后两者更能显著降低图像噪声,提高CNR、SNR,提升肋软骨的主观图像质量,为制定最佳术前方案提供更精准的相关信息,可作为肋软骨CT检查首选算法重建技术进行应用,值得大力推广。

Objective: To investigate the effects of IMR, iDose4 and FBP reconstruction algorithms on the image quality of multi-row spiral CT in the chest before costal cartilage rhinoplasty. Methods: A total of 60 patients who met the inclusion criteria and planned to receive autogenous costal cartilage rhinoplasty were collected. All patients underwent chest CT examination before operation and completed relevant 3D reconstruction based on images generated by IMR, iDose4 and FBP reconstruction algorithms, and the image quality of the three reconstruction algorithms was analyzed. The subjective evaluation score and objective evaluation indexes of image quality in each group were recorded and compared including costal cartilage CT value, noise, signal-to-noise ratio and contrast noise ratio. Results: The CT reconstruction images obtained by the three algorithms could all accurately assess the degree of costal cartilage calcification. Subjective evaluation of image quality showed that the IMR group obtained higher score and held obvious advantages, mainly reflected in the IMR reconstruction algorithm compared with iDose4 and FBP two algorithms in the costal cartilage calcification spot edge display and inhibition of liver,gastrointestinal content and weakened heart beating artifacts. Objective evaluation of costal cartilage CT value,SNR, contrast noise ratio and statistical analysis, the final statistical results showed that IMR, iDose4 and FBP reconstruction algorithm group showed significant statistical differences, IMR group showed obviously the best image quality. Conclusion: All three reconstruction algorithms of IMR, idose4 and FBP can accurately evaluate the presence and degree of calcification of autologous costal cartilage. Under the same scanning conditions, compared with the reconstruction algorithms of FBP and iDose4, IMR reconstruction algorithms can reducecan significantly reduce image noise, improve CNR and SNR, and improve the subjective image quality of costal cartilage. It is more acceptable to clinical surgeons and can be used as the preferred algorithm reconstruction technique for costal cartilage CT examination, which is most worthy of promotion.