儿童肺部感染征象MRI特征识别的初步研究

Primary study on pulmonary MRI in children with pulmonary infection

目的评估肺部MRI对儿童肺部感染的征象识别,探讨其临床诊断价值。方法选取35例肺部感染儿童在48 h内进行CT及MRI平扫。对比CT图像,由2位医师对胸部病变征象(结节、实变、磨玻璃、囊泡、支气管扩张、胸腔积液、淋巴结)进行MRI不同序列间、MRI与CT间的征象识别进行评估和比较,应用卡方检验分析MRI序列与结节大小的关系。结果CT检出307个病灶,MRI检出268个(87.3%,95%CI 82.9%~90.7%)。CT检出212个结节中,189个(89.2%,95%CI 84%~92.9%)在MRI显示。超短回波时间序列对1~4 mm结节的敏感性达到88.9%(95%CI 75.2%~95.8%),对磨玻璃检测的敏感性为55.6%(95%CI 35.6%~74%)。46个实变病灶在MRI的4个序列均观察到,敏感性达100%(95%CI 90.4%~100%)。结论MR超短回波时间序列和PROPELLER T2WI序列对肺内征象的显示具有良好的敏感性,尤其是超短回波时间序列对肺结节、磨玻璃的敏感性较高。

Objective To evaluate the value of MRI in the diagnosis of pulmonary infection in children.Methods 35 children were clinically diagnosed with pulmonary infection;Unenhanced CT and MRI scan were performed within 48 hours.In contrast to CT image,two radiologists evaluated signs of abnormal lung lesions(nodules,consolidation,ground glass,necrosis,vesicles,bronchiectasis,pleural effusion and lymph nodes)between different sequences by MRI.Relationship between MR sequences and nodule size was examined by chi-square test(Pearson chi-square and Fisher exact test).Results Of 307 CT lesions,268(87.3%,95%confidence interval CI 82.9%~90.7%)were detected at MRI.Of 212 CT-detected nodules,189(89.2%,95%confidence interval CI 84%~92.9%)were seen on MRI.Of the 1-4mm nodules,the sensitivity of the ultra-short echo time series was 88.9%(95%confidence interval CI 75.2%~95.8%).The ground glass was detected on ultra-short echo time sequence MRI with a sensitivity of 55.6%(95%confidence interval CI 35.6%~74%).The consolidations were observed in all 4 MRI sequences,with a sensitivity of 100%(95%confidence interval CI 90.4%~100%).Conclusion MR ultra-short echo time sequence and PROPELLER T2 weighted sequence have a good sensitivity to the detection of pulmonary lesions,especially the ultra-short echo time sequence that has a high sensitivity to pulmonary nodules and ground glass.