SSFSE和FIESTA序列在正常胎肺生物学测量中的对比研究

Comparative Study of SSFSE and FIESTA Sequences in Biological Measurement of Normal Fetal Lung

目的 基于SSFSE和FIESTA序列评价不同孕周正常胎肺体积及肺-肝信号强度比(LLSIR)值,建立22~38周正常胎儿肺体积的参考范围。方法 回顾性分析行胎儿磁共振SSFSE和FIESTA序列检查的330例单胎妊娠患者资料。使用ITK-SNAP软件描点勾勒,测出22~38周胎儿左、右肺及总肺体积的平均值、中位数、标准差、最小、最大值、上、下四分位数及95%置信区间。采用配对t检验对SSFSE和FIESTA序列所测左肺、右肺、总肺体积及LLSIR结果进行比较。结果 正常中晚期单胎妊娠,胎肺体积及LLSIR均与孕周呈显著正相关(均P<0.01)。SSFSE和FIESTA序列测得22~38周胎儿左肺、右肺及总肺体积差异无统计学意义(均P>0.05);而SSFSE和FIESTA序列测得LLSIR差异具有统计学意义(均P<0.01)。结论 胎儿肺体积与LLSIR随着胎儿孕周的增加而增加;FIESTA可替代SSFSE序列进行胎儿肺体积测量,但使用LLSIR来评估胎肺发育时应视具体情况而定。

Objective The purpose of this study is to evaluate the normal fetal lung volume and the ratio of fetal lung and liver signal intensity along with gestational age, based on FIESTA and SSFSE sequences, and to establish normal total fetal lung volume reference ranging from 22 to 38 weeks’ gestation at 2-week intervals. Methods A retrospective analysis of 330 patients who underwent fetal MRI was performed.The images were imported into ITK-SNAP software, the continuous trace method was used to outline the bilateral fetal lungs layer by layer.The mean, median, standard deviation, minimum, maximum, upper and lower quartiles and 95% confidence interval for left lung, right and total lung volume were determined every two weeks.Paired t test was performed on the left, right lung and total lung volume results obtained from FIESTA and SSFSE sequence. Results In the normal middle and late singleton pregnancy, the lung volume and lung-liver signal ratio gradually increased with the increase of gestational age.The LLV,RLV and TLV values of the fetuses at 22-38 weeks measured by FIESTA and SSFSE sequence showed no statistical difference paired with t test(P>0.05),while the lung-liver signal ratio showed that there was a statistical difference(P<0.05). Conclusion The FLV and LLSIR showed a significant positive correlation with the increase of fetal gestational age.There is no significant difference between FIESTA and SSFSE sequences in measuring fetal lung volume at different gestational weeks.