ABSTRACT
Objective:To explore the value of MRI signs in assessing the presence or absence of hernia sacs in fetuses with congenital diaphragm hernia.Methods:MRI images of 57 patients with congenital diaphragm hernia confirmed by postpartum surgery were analyzed from November 2016 to December 2020 in Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, with a gestational age of 20－40 (28±5) weeks. In postpartum surgery, 18 cases were found with hernia sacs (hernia sac group) and 39 cases without hernia sacs (hernia-free group). Seven MRI signs were analyzed, including hernia peripheral enveloping sensation, smooth lung-hernia interface, crescent-shaped lung compression, residual lung tissue on the affected side, heart displacement, effusion above the lung-hernia interface and effusion below the lung-hernia interface. The differences in MRI signs between the hernia sac and hernia-free groups were compared using the χ 2 test or Fisher′s exact probability method. The diagnostic efficacy of each sign was calculated. The MRI signs with statistical differences between the two groups were included in the predictive integration model, and 1 point was scored for each sign, the imaging score of each fetus was calculated, and the efficacy of imaging points in diagnosing the presence or absence of hernia sacs was assessed by the subject manipulation receiver operating characteristics (ROC) curve. Results:There were statistically significant differences in 5 MRI signs between the hernia sac and the hernia-free groups, namely hernia peripheral enveloping sensation (χ2=25.74, P<0.001), smooth lung-hernia interface (χ2=48.20, P<0.001), crescent-shaped lung compression (χ2=57.00, P<0.001), residual lung tissue on the affected side (χ2=12.14, P<0.001) and effusion above the lung-hernia interface (χ2=4.31, P=0.022). Among them, the sign of crescent-shaped lung compression had the highest diagnostic efficacy, and the sensitivity, specificity and accuracy all were 100%. Five statistically significant MRI signs were included in the predictive integration model, and the area under the ROC curve was 0.999, the sensitivity was 100%, the specificity was 94.9%, and the optimal threshold was 2 points. Conclusion:Fetal MRI signs and predictive integration model can effectively identify the presence or absence of hernia sacs in fetuses with congenital diaphragm hernia, which has certain clinical significance.
ABSTRACT
Objective To investigate the supplementary roles of MRI in the diagnosis of fetal abnormalities in twin fetuses.Methods MRI manifestations of 22 twins were retrospectively analyzed after abnormalities were found by prenatal ultrasonography (US) from Sep 2005 to Dec 2012.Two rapid scanning sequences were used in the study,fast-imaging employing steady-state acquisition (FIESTA) and fast inversion recovery motion insensitive (FIRM).MRI findings were compared with those of prenatal US,induced labour or postpartum diagnosis.Results A total of 22 twins were reported with 23 abnormal fetuses in 20 twins and 2 normal twins.MRI confirmed central nervous system abnormalities in 3 abnormal fetuses which were anencephalus,meningoencephalocele and enlargement of lateral ventricles respectively.The case of meningoencephalocele was showed brain tissue protruding from the occipital defect on MRI,which was misdiagnosed as a cystic lymphagioma by US.The MRI diagnosis of anencephalus and enlarged lateral ventricles were accordant with US.MRI made the definite diagnosis in 5 chest abnormalities,which were left congenital diaphragmatic hernia (CDH) in 5 abnormal fetuses.They were diagnosed as possible CDH by US.Abdominal abnormalities (n=7,8 abnormal fetuses) included two fetuses in one twin with expanded digestive tract,one fetus with expanded colon and rectus and five fetuses with omphalocele.MRI diagnosis was compatible with US diagnosis in the 7 cases.Twins micromelia were found in one case with 2 abnormal fetuses.Conjoined twins in chest and abdomen were found in another case,which manifested as two hearts,one shared liver and independent urinary tracts and gastrointestinal tracts on MRI.One fetus in twin was dead (n=1,1 abnormal fetus).MRI showed small size and skin edema of the dead fetus.One acephalus acardius of twins (n=2,2 abnormal fetuses) was proved.Normal MRI manifestations were indicated in 2 cases which were suspected by US for abnormal digestive tract and cryptorachischisis respectively.Conclusions MRI,an important supplementary method of prenatal US diagnosis,shows valuable advantages including multi-plane manifestations,more extensive visual field and good soft tissue contrast.It is especially helpful in the diagnosis and treatment of multiple pregnancy.