OP22.03: Fetal brain MRI: novel classification and contribution to sonography (original) (raw)

In spite of the high dose administration of artificial lung surfactant, some neonates show the severe respiratory disorder (SRD) in premature delivery. In these cases, the problem is not the deficiency of surfactant, but the maturity of the lung. Since lung fluid secreted by fetal lungs is essential for the fetal lung maturity, the measurement of water content of the lung on T2-weighted images may predict the fetal lung maturity. Therefore, we measured the fetal lung-to-liver signal intensity ratio (LLSIR) on T2-weighted images and examined the relations between LLSIR and presence of the SRD after birth. The purpose of this study is to determine the fetal LLSIR on T2-weighted images as an accurate prenatal evaluating method for fetal lung maturity. Methods: One hundred twenty fetuses who underwent MRI examination in various indications after 22nd week of gestation participated in this study with their parents' consent. LLSIR was measured on T2-weighted images of MRI. We examined the changes of the ratio with the progress of gestational week at first and then the relations between LLSIR and presence of the SRD after birth. The best cutoff value of the LLSIR to predict respiratory outcome after birth was calculated using Receiver Operating Characteristic (ROC) analysis. Results: LLSIR correlated significantly with advancing of gestational age. The relationship between LLSIR(y) and gestational age(x) was shown as y = 0.037x + 0.97 (R = 0.31, p < 0.005). The non-SRD group had higher LLSIR when compared with the SRD group (2.16 ± 0.30 vs. 1.53 ± 0.40, p < 0.001). ROC curve analysis showed that fetuses with an LLSIR below 2.00 were more likely to develop SRD (sensitivity: 100%, specificity: 75%). Conclusions: The fetal LLSIR on T2-weighted images is an important and useful marker to diagnose the fetal lung maturity.