基于低剂量胸部CT原始数据迭代重建增强等级评价不同类型肺小结节的初步分析

A Preliminary Analysis of Using the Sinogram-affirmed Iterative Reconstruction Strength Levels based on the Original Data of Low-dose Chest CT to Evaluate Different Types of Small Pulmonary Nodules

目的:探讨低剂量胸部CT(LDCT)原始数据迭代重建(SAFIRE)增强等级与不同类型(实性、部分实性及纯磨玻璃)肺小结节优化显示的对应关系。材料与方法:分析2020年9月至2021年1月行LDCT并符合肺小结节入组标准受试者101例105个肺小结节,依结节性质分为实性结节组(n=27),部分实性结节组(n=37)和纯磨玻璃结节组(n=41)。采用单因素方差分析、卡方检验或Kruskal-Wallis H检验先分析组间一般资料,再以滤波反投影算法(FBP,B50f)为参照,比较SAFIRE I50f和I70f(分别1~5级)各模式下客观图像质量(噪声值、肺小结节CT值、SNR和CNR)和主观图像质量评分。结果:(1)三组在性别、身体质量指数和结节分布无显著差异,纯磨玻璃结节组年龄和结节长径均小于实性和部分实性结节组;(2)SAFIRE I50f 1~5和I70f-5图像噪声值均低于FBP B50f,其中SAFIRE I50f-5噪声值最低,不同模式下肺小结节CT值无显著差异,SAFIRE I50f-5肺小结节SNR和CNR均高于FBP B50f和其他SAFIRE模式;(3)SAFIRE I50f 3~5实性和部分实性肺小结节图像质量主观评分高于FBP B50f和除I70f-5外SAFIRE其他模式,SAFIRE I50f-4纯磨玻璃肺小结节图像质量主观评分高于FBP B50f和除I50f-3、I50f-5外SAFIRE其他模式且组间评分无显著差异。结论:SAFIRE I50f-4在LDCT实性、部分实性和纯磨玻璃肺小结节图像质量客观、主观评价方面均表现良好且均衡,可适用于各类型肺小结节LDCT评价。

Objective:We intend to explore the Corresponding relations between the Sinogram-affirmed iterative reconstruction(SAFIRE)strength levels and the optimized display of different types(solid,partially solid,and pure ground glass)of small pulmonary nodules in low-dose chest CT(LDCT).Materials and methods:We analyzed 105 small pulmonary nodules in 101 patients who underwent LDCT from September 2020 to January 2021 and also met the criteria for small pulmonary nodules.Based on nodule composition,they were divided into the solid nodule Group(n=27),the partially solid nodule group(n=37)and the pure ground glass nodule group(n=41).First we adopted the one-way analysis of variance,Chi-square test or Kruskal-Wallis H test to analyze the general data in groups,then took the filtered back projection algorithm(FBP,B50 f)as the reference to compare the difference in objective image quality(including noise value,CT value of small pulmonary nodules,SNR and CNR)and subjective image quality in groups under different SAFIRE modes(I50 f and I70 f,strength levels 1 to 5 respectively).Results:1 There was no significant difference in gender,body mass index,and nodule distribution in three groups.The age and length of the nodules in the pure ground-glass nodule group were smaller than those in the solid and partial solid nodule groups;2 The image noise values in SAFIRE I50 f 1-5 and I70 f-5 were lower than that in FBP B50 f while SAFIRE I50 f-5 showed the lowest noise value.There was no significant difference in CT values of small pulmonary nodules in the three groups under different modes,the SNR and CNR of small pulmonary nodules in SAFIRE I50 f-5 were higher than those of FBP B50 f and other SAFIRE modes;3 SAFIRE I50 f 3~5 of solid and partial solid pulmonary nodule groups obtained higher subjective scores than that of FBP B50 f and other SAFIRE modes except I70 f-5.SAFIRE I50 f-4 of pure ground glass nodule group obtained a higher subjective score than those of FBP B50 f and other SAFIRE modes except I50 f-3 and I50 f-5,and there was no significant difference in the subjective scores in three groups under this mode(P=0.428).Conclusion:SAFIRE I50 f-4 performed well and displayed a balanced effect in the objective and subjective evaluation of solid,partial solid and pure ground glass small pulmonary nodules in LDCT.We suggest it can be applied to evaluate different types of small pulmonary nodules in LDCT.