Timing of Prenatal Magnetic Resonance Imaging in the Assessment of Congenital Diaphragmatic Hernia

Observed-to-expected lung-area-to-head-circumference ratio on ultrasound examination vs total fetal lung volume on magnetic resonance imaging in prediction of survival in fetuses with left-sided diaphragmatic hernia

OBJECTIVE

To assess and compare the value of antenatally determined observed-to-expected (O/E) lung-area-to-head-circumference ratio (LHR) on ultrasound examination vs O/E total fetal lung volume (TFLV) on magnetic resonance imaging (MRI) examination to predict postnatal survival of fetuses with isolated, expectantly managed left-sided congenital diaphragmatic hernia (CDH).

METHODS

This was a multicenter retrospective study including all consecutive fetuses with isolated CDH that were managed expectantly in Mannheim, Germany, and in five other European centers, that underwent at least one ultrasound examination for measurement of O/E-LHR and one MRI scan for measurement of O/E-TFLV during pregnancy. All MRI data were centralized, and lung volumes were measured by two experienced operators blinded to the pre- and postnatal data. Multiple logistic regression analyses were performed to examine the effect on survival at hospital discharge of various perinatal variables, including the center of management. In left-sided CDH with intrathoracic herniation of the liver, receiver-operating-characteristics (ROC) curves were constructed separately for cases from Mannheim and the other five European centers and were used to compare O/E-TFLV and O/E-LHR in the prediction of postnatal survival.

RESULTS

From Mannheim, 309 patients were included with a median gestational age (GA) at ultrasound examination of 29.6 (range, 19.7-39.1) weeks and median GA at MRI examination of 31.1 (range, 18.0-39.9) weeks. From the other five European centers, 116 patients were included with a median GA at ultrasound examination of 26.7 (range, 20.6-37.6) weeks and median GA at MRI examination of 27.7 (range, 21.3-37.9) weeks. Regression analysis demonstrated that the survival rates at discharge were lower in left-sided CDH (odds ratio (OR), 0.349 (95% CI, 0.133-0.918), P = 0.033) and those with intrathoracic liver (OR, 0.297 (95% CI, 0.141-0.628), P = 0.001), and higher with increasing O/E-TFLV (OR, 1.123 (95% CI, 1.079-1.170), P < 0.001), advanced GA at birth (OR, 1.294 (95% CI, 1.055-1.588), P = 0.013) and when birth occurred in Mannheim (OR, 7.560 (95% CI, 3.368-16.967), P < 0.001). Given the difference in survival rate between Mannheim and the five other European centers, ROC curve comparisons between the two imaging modalities were presented separately. For cases of left-sided CDH with intrathoracic herniation of the liver, pairwise comparison showed no significant difference between the area under the ROC curves for the prediction of postnatal survival between O/E-TFLV and O/E-LHR in Mannheim (mean difference = 0.025, P = 0.610, standard error = 0.050), whereas there was a significant difference in the other European centers studied (mean difference = 0.056, P = 0.033, standard error = 0.056).

CONCLUSIONS

In fetuses with left-sided CDH and intrathoracic herniation of the liver, the predictive value for postnatal survival of O/E-TFLV on MRI examination and O/E-LHR on ultrasound examination was similar in one center (Mannheim), but O/E-TFLV had better predictive value compared to O/E-LHR in the five other European centers. Hence, in these five European centers, MRI should be included in the diagnostic process for left-sided CDH. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Timing of magnetic resonance imaging in pregnancy for outcome prediction in congenital diaphragmatic hernia

PURPOSE

To evaluate the impact of the timing of MRI on the prediction of survival and morbidity in patients with CDH, and whether serial measurements have a beneficial value.

METHODS

This retrospective cohort study was conducted in two perinatal centers, in Germany and Italy. It included 354 patients with isolated CDH having at least one fetal MRI. The severity was assessed with the observed-to-expected total fetal lung volume (o/e TFLV) measured by two experienced double-blinded operators. The cohort was divided into three groups according to the gestational age (GA) at which the MRI was performed (< 27, 27-32, and  > 32 weeks' gestation [WG]). The accuracy for the prediction of survival at discharge and morbidity was analyzed with receiver operating characteristic (ROC) curves. Multiple logistic regression analyses and propensity score matching examined the population for balance. The effect of repeated MRI was evaluated in ninety-seven cases.

RESULTS

There were no significant differences in the prediction of survival when the o/e TFLV was measured before 27, between 27 and 32, and after 32 WG (area under the curve [AUC]: 0.77, 0.79, and 0.77, respectively). After adjustment for confounding factors, it was seen, that GA at MRI was not associated with survival at discharge, but the risk of mortality was higher with an intrathoracic liver position (adjusted odds ratio [aOR]: 0.30, 95% confidence interval [95%CI] 0.12-0.78), lower GA at birth (aOR 1.48, 95%CI 1.24-1.78) and lower o/e TFLV (aOR 1.13, 95%CI 1.06-1.20). ROC curves showed comparable prediction accuracy for the different timepoints in pregnancy for pulmonary hypertension, the need of extracorporeal membrane oxygenation, and feeding aids. Serial measurements revealed no difference in change rate of the o/e TFLV according to survival.

CONCLUSION

The timing of MRI does not affect the prediction of survival rate or morbidity as the o/e TFLV does not change during pregnancy. Clinicians could choose any gestational age starting mid second trimester for the assessment of severity and counseling.

Magnetic resonance imaging in the second trimester as a complement to ultrasound for diagnosis of fetal anomalies

Background

Fetal ultrasound has limitations, especially if the patient is obese or in cases with oligohydramnios. Magnetic resonance imaging (MRI) can then be used as a complement, but only few studies have focused on examinations in the second trimester.

Purpose

To validate MRI as a complement to diagnose fetal anomalies in the second trimester.

Material and Methods

This retrospective study retrieved data from January 2008 to July 2012 from the Fetal Medicine Unit and Department of Radiology at Uppsala University Hospital. Ultrasound and MRI findings were reviewed in 121 fetuses in relation to the final diagnosis, including postpartum follow-up and autopsy results.

Results

Of the 121 fetuses, 51 (42%) had a CNS anomaly and 70 (58%) a non-CNS anomaly diagnosed or suspected. MRI provided additional information in 21% of all cases without changing the management and revealed information that changed the management of the pregnancy in 13%. When a CNS anomaly was detected or suspected, the MRI provided additional information in 22% and changed the management in 10%. The corresponding figures for non-CNS cases were 21% and 16%, respectively. The proportion of cases with additional information that changed the management was especially high in patients with a BMI >30 kg/m2 (25%) and in patients with oligohydramnios (38%). In five cases in category III, false-positive ultrasound findings were identified.

Conclusions

MRI in the second trimester complements ultrasound and improves diagnosis of fetal CNS- and non-CNS anomalies especially when oligohydramnios or maternal obesity is present.

Does Prediction of Neonatal Mortality by the Observed/Expected Lung-To-Head Ratio Change during Pregnancy in Fetuses with Left Congenital Diaphragmatic Hernia?

INTRODUCTION

The aim of this study was to evaluate prediction of neonatal mortality in fetuses with isolated left congenital diaphragmatic hernia (CDH) when the observed/expected lung-to-head ratio (O/E LHR) was estimated at two different gestational time points during pregnancy.

METHODS

Forty-four (44) fetuses with isolated left CDH were included. O/E LHR was estimated at the time of referral (first scan) and before delivery (last scan). The main outcome was neonatal death due to respiratory complications.

RESULTS

There were 10/44 (22.7%) perinatal deaths. The areas under (AU) the ROC curves were: first scan, 0.76, best O/E LHR cut-off 35.5% with 76% sensitivity and 70% specificity; last scan, AU-ROC 0.79, best O/E LHR cut-off 35.2%, with 79.0% sensitivity and 80% specificity. Considering an O/E LHR cut-off ≤35% to define high-risk fetuses at any examination, prediction for perinatal mortality showed: 80% sensitivity, 73.5% specificity, 47.1% positive and 92.6% negative predictive values, and 3.02 (95% CI 1.59-5.73) positive and 0.27 (95% CI 0.08-0.96) negative likelihood ratios. Prediction was similar in the two evaluations as 16/21 (76.2%) of fetuses considered at risk had an O/E LHR ≤35% in the two examinations; in the remaining 5 cases, two were identified only in the first and three only in the last scan.

CONCLUSION

The O/E LHR is a good predictor of perinatal death in fetuses with left isolated CDH. Approximately 80% of fetuses at risk of perinatal death can be identified with an O/E LHR ≤35%, and 90% of them will have similar O/E LHR values at the first and at the last ultrasound examinations prior to delivery. In general, 88.6% of all CDH fetuses have a similar severity classification based on the O/E LHR at the first diagnostic ultrasound or at the ultrasound examination prior to delivery.

Fetal MRI Neuroradiology: Indications

Fetal MRI is a safe, noninvasive examination of the fetus and placenta, a complement to ultrasonography. MRI provides detailed CNS evaluation, including depicting parenchymal architecture and posterior fossa morphology, and is key in prenatal assessment of spinal dysraphism, neck masses, and ventriculomegaly. Fetal MRI is typically performed after 22 weeks gestation, and ultrafast T1 and T2-weighted MRI sequences are the core of the exam, with advanced sequences such as diffusion weighted imaging used for specific questions. The fetal brain grows and develops rapidly, and familiarity with gestational age specific norms is essential to MRI interpretation.

Genetically Modified Mouse Models of Congenital Diaphragmatic Hernia: Opportunities and Limitations for Studying Altered Lung Development

Congenital diaphragmatic hernia (CDH) is a relatively common and life-threatening birth defect, characterized by an abnormal opening in the primordial diaphragm that interferes with normal lung development. As a result, CDH is accompanied by immature and hypoplastic lungs, being the leading cause of morbidity and mortality in patients with this condition. In recent decades, various animal models have contributed novel insights into the pathogenic mechanisms underlying CDH and associated pulmonary hypoplasia. In particular, the generation of genetically modified mouse models, which show both diaphragm and lung abnormalities, has resulted in the discovery of multiple genes and signaling pathways involved in the pathogenesis of CDH. This article aims to offer an up-to-date overview on CDH-implicated transcription factors, molecules regulating cell migration and signal transduction as well as components contributing to the formation of extracellular matrix, whilst also discussing the significance of these genetic models for studying altered lung development with regard to the human situation.

Prenatal lung volumes in congenital diaphragmatic hernia and their effect on postnatal outcomes

Lung volume measurement on fetal MRI is a component of the imaging workup for various prenatal conditions, but its use as a prognosticator has been most heavily studied in congenital diaphragmatic hernia (CDH). Pediatric radiologists who perform and interpret fetal MRI must be familiar with the technical aspects of lung volume measurement to guarantee accurate measurement and reporting. Variability in timing and type of measurement at different fetal centers also requires pediatric radiologists to be up-to-date with the literature and aware of their center's internal data. This paper provides both a how-to guide for measuring fetal lung volumes on MRI and a comprehensive review of the CDH outcome literature to serve as a convenient reference for the pediatric radiologist.

Magnetic Resonance Prediction of Lung Maturity in Fetuses With Congenital Diaphragmatic Hernia

ABSTRACT

To determine if lung to liver MR T2 signal ratio is predictive of neonatal outcome in fetuses with congenital diaphragmatic hernia (CDH).After Interal Review Board approval, the PACS systems at the University of Washington and University of Utah were searched for cases having an in utero fetal MR examination diagnostic of CDH. Inclusion criteria were at least 1 prior ultrasound demonstrating a CDH and an MR obtained within 1 week of that prior ultrasound.A total of 69 patients from the University of Utah and 13 from the University of Washington satisfied the inclusion criteria for a total of 82. After adjusting for gestational age and contralateral lung volume, there was little apparent association between contralateral lung to liver MR T2 signal and 5-minute Apgar score and neonatal mortality When considering neonatal Apgar and mortality, increasing contralateral lung volume was significantly associated with lower risk (hazard ratio, 0.40 per doubling; 95% confidence interval, 0.24-0.69; P = 0.001) as expected.Our data demonstrate that the lung to liver MR signal ratio was not predictive of outcome. The measurement of contralateral lung area, and gestational age at the time of the examination (time of diagnosis) are still the best predictors of poor neonatal outcome.