Three-dimensional reconstruction of defects in congenital diaphragmatic hernia: a fetal MRI study

Fetal MRI: what's new? A short review

Fetal magnetic resonance imaging (fetal MRI) is usually performed as a second-level examination following routine ultrasound examination, generally exploiting morphological and diffusion MRI sequences. The objective of this review is to describe the novelties and new applications of fetal MRI, focusing on three main aspects: the new sequences with their applications, the transition from 1.5-T to 3-T magnetic field, and the new applications of artificial intelligence software. This review was carried out by consulting the MEDLINE references (PubMed) and including only peer-reviewed articles written in English. Among the most important novelties in fetal MRI, we find the intravoxel incoherent motion model which allow to discriminate the diffusion from the perfusion component in fetal and placenta tissues. The transition from 1.5-T to 3-T magnetic field allowed for higher quality images, thanks to the higher signal-to-noise ratio with a trade-off of more frequent artifacts. The application of motion-correction software makes it possible to overcome movement artifacts by obtaining higher quality images and to generate three-dimensional images useful in preoperative planning.Relevance statementThis review shows the latest developments offered by fetal MRI focusing on new sequences, transition from 1.5-T to 3-T magnetic field and the emerging role of AI software that are paving the way for new diagnostic strategies.Key points• Fetal magnetic resonance imaging (MRI) is a second-line imaging after ultrasound.• Diffusion-weighted imaging and intravoxel incoherent motion sequences provide quantitative biomarkers on fetal microstructure and perfusion.• 3-T MRI improves the detection of cerebral malformations.• 3-T MRI is useful for both body and nervous system indications.• Automatic MRI motion tracking overcomes fetal movement artifacts and improve fetal imaging.

Connecting clinical, environmental, and genetic factors point to an essential role for vitamin A signaling in the pathogenesis of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a developmental disorder that results in incomplete diaphragm formation, pulmonary hypoplasia, and pulmonary hypertension. Although a variety of genes have been linked to its etiology, CDH is not a monogenetic disease, and the cause of the condition is still unclear in the vast majority of clinical cases. By comparing human clinical data and experimental rodent data from the literature, we present clear support demonstrating the importance of vitamin A (vitA) during the early window of pregnancy when the diaphragm and lung are forming. Alteration of vitA signaling via dietary and genetic perturbations can create diaphragmatic defects. Unfortunately, vitA deficiency is chronic among people of child-bearing age, and this early window of diaphragm development occurs before many might be aware of pregnancy. Furthermore, there is an increased demand for vitA during this critical period, which exacerbates the likelihood of deficiency. It would be beneficial for the field to further investigate the connections between maternal vitA and CDH incidence, with the goal of determining vitA status as a CDH risk factor. Regular clinical monitoring of vitA levels in child-bearing years is a tractable method by which CDH outcomes could be prevented or improved.

The Role of 3D Printing in Planning Complex Medical Procedures and Training of Medical Professionals-Cross-Sectional Multispecialty Review

Medicine is a rapidly-evolving discipline, with progress picking up pace with each passing decade. This constant evolution results in the introduction of new tools and methods, which in turn occasionally leads to paradigm shifts across the affected medical fields. The following review attempts to showcase how 3D printing has begun to reshape and improve processes across various medical specialties and where it has the potential to make a significant impact. The current state-of-the-art, as well as real-life clinical applications of 3D printing, are reflected in the perspectives of specialists practicing in the selected disciplines, with a focus on pre-procedural planning, simulation (rehearsal) of non-routine procedures, and on medical education and training. A review of the latest multidisciplinary literature on the subject offers a general summary of the advances enabled by 3D printing. Numerous advantages and applications were found, such as gaining better insight into patient-specific anatomy, better pre-operative planning, mock simulated surgeries, simulation-based training and education, development of surgical guides and other tools, patient-specific implants, bioprinted organs or structures, and counseling of patients. It was evident that pre-procedural planning and rehearsing of unusual or difficult procedures and training of medical professionals in these procedures are extremely useful and transformative.

The role of magnetic resonance imaging in the diagnosis and prognostic evaluation of fetuses with congenital diaphragmatic hernia

In recent years, magnetic resonance imaging (MRI) has largely increased our knowledge and predictive accuracy of congenital diaphragmatic hernia (CDH) in the fetus. Thanks to its technical advantages, better anatomical definition, and superiority in fetal lung volume estimation, fetal MRI has been demonstrated to be superior to 2D and 3D ultrasound alone in CDH diagnosis and outcome prediction. This is of crucial importance for prenatal counseling, risk stratification, and decision-making approach. Furthermore, several quantitative and qualitative parameters can be evaluated simultaneously, which have been associated with survival, postnatal course severity, and long-term morbidity.

CONCLUSION

Fetal MRI will further strengthen its role in the near future, but it is necessary to reach a consensus on indications, methodology, and data interpretation. In addition, it is required data integration from different imaging modalities and clinical courses, especially for predicting postnatal pulmonary hypertension. This would lead to a comprehensive prognostic assessment.

WHAT IS KNOWN

• MRI plays a key role in evaluating the fetal lung in patients with CDH. • Prognostic assessment of CDH is challenging, and advanced imaging is crucial for a complete prenatal assessment and counseling.

WHAT IS NEW

• Fetal MRI has strengthened its role over ultrasound due to its technical advantages, better anatomical definition, superior fetal lung volume estimation, and outcome prediction. • Imaging and clinical data integration is the most desirable strategy and may provide new MRI applications and future research opportunities.

Development of a 3D printed patient-specific neonatal brain simulation model using multimodality imaging for perioperative management

BACKGROUND

Medical-imaging-based three-dimensional (3D) printed models enable improvement in skills training, surgical planning, and decision-making. This pilot study aimed to use multimodality imaging and to add and compare 3D ultrasound as a future standard to develop realistic neonatal brain models including the ventricular system.

METHODS

Retrospective computed tomography (CT), magnetic resonance imaging (MRI), and 3D ultrasound-based brain imaging protocols of five neonatal patients were analyzed and subsequently segmented with the aim of developing a multimodality imaging-based 3D printed model. The ventricular anatomy was analyzed to compare the MRI and 3D ultrasound modalities.

RESULTS

A realistic anatomical model of the neonatal brain, including the ventricular system, was created using MRI and 3D ultrasound data from one patient. T2-weighted isovoxel 3D MRI sequences were found to have better resolution and accuracy than 2D sequences. The surface area, anatomy, and volume of the lateral ventricles derived from both MRI and 3D ultrasound were comparable.

CONCLUSIONS

We created an ultrasound- and MRI-based 3D printed patient-specific neonatal brain simulation model that can be used for perioperative management. To introduce 3D ultrasound as a standard for 3D models, additional dimensional correlations between MRI and ultrasound need to be examined.

IMPACT

We studied the feasibility of implementing 3D ultrasound as a standard for 3D printed models of the neonatal brain. Different imaging modalities were compared and both 3D isotropic MRI and 3D ultrasound imaging are feasible for printing neonatal brain models with good dimensional accuracy and anatomical replication. Further dimensional correlations need to be defined to implement it as a standard to produce 3D printed models.

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.

Prenatal stomach position and volume in relation to postnatal outcomes in left-sided congenital diaphragmatic hernia

Objective

To examine the association between prenatal stomach position (SP) grade and stomach volume (SV) and the need for pulmonary hypertension (PH) treatment after birth in prenatally diagnosed left‐sided congenital diaphragmatic hernia (CDH), live born >34 weeks.

Methods

In retrospect, SP grade and SV were determined in fetuses with isolated left‐sided CDH from 19 weeks gestational age (GA) onwards at three different time periods (≤24 weeks' GA: US1, 24–30 weeks' GA: US2; ≥30 weeks' GA: US3). Primary outcome was need for treatment of PH after birth. Secondary analyses included the predictive value of SP and SV for other respiratory outcomes and postnatal defect size.

Results

A total of 101 fetuses were included. SP grade was significantly associated with need for treatment of PH (US1, US2, and US3: p < 0.02). Also, prenatal SP grade was positively associated with defect size and development of chronic lung disease (CLD) in survivors. No association was found between SV and respiratory morbidities or postnatal defect size.

Conclusion

SP grade in left‐sided CDH fetuses is associated with an increased need for PH treatment, a larger postnatal defect size and CLD in survivors. We consider SP determination a valuable contribution to the prenatal assessment of left‐sided CDH.

What is already known about this topic?

Prenatal stomach position (SP) grade has been proposed as a predictive ultrasound parameter for postnatal survival, patch repair, need for extracorporeal membrane oxygenation and need for prolonged respiratory support in left‐sided congenital diaphragmatic hernia (CDH).

What does this study add?

In children with left‐sided CDH, prenatal SP grade is associated with an increase in need for treatment of pulmonary hypertension and development of chronic lung disease, with the greatest increase in SP Grade 2 and 4.

A higher prenatal SP grade is associated with a larger postnatal defect size.

In the majority of cases SP grade does not vary throughout gestation.

Fetal body MRI and its application to fetal and neonatal treatment: an illustrative review

This Review depicts the evolving role of MRI in the diagnosis and prognostication of anomalies of the fetal body, here including head and neck, thorax, abdomen and spine. A review of the current literature on the latest developments in antenatal imaging for diagnosis and prognostication of congenital anomalies is coupled with illustrative cases in true radiological planes with viewable three-dimensional video models that show the potential of post-acquisition reconstruction protocols. We discuss the benefits and limitations of fetal MRI, from anomaly detection, to classification and prognostication, and defines the role of imaging in the decision to proceed to fetal intervention, across the breadth of included conditions. We also consider the current capabilities of ultrasound and explore how MRI and ultrasound can complement each other in the future of fetal imaging.

Is fetal magnetic resonance imaging volumetry of eventrated organs in gastroschisis predictive for surgical treatment?

BACKGROUND

Fetal MRI is increasingly used in congenital abdominal wall defects. In gastroschisis, the role of fetal MRI in surgical therapy is poorly understood. Currently, the type of repair is determined primarily by clinical presentation and institutional preference.

OBJECTIVE

To evaluate the feasibility of fetal MRI volumetry in gastroschisis treatment.

MATERIALS AND METHODS

We included 22 cases of gastroschisis in this retrospective single-center study. Routine fetal MRI scans were acquired between Jan. 1, 2006, and July 1, 2018, at gestational ages of 19-34 postmenstrual weeks. Fetal-MRI-based manual segmentation and volumetry were performed utilizing steady-state free precision and T2-weighted sequences. Acquired parameters included intraabdominal volume, eventrated organ volume and total fetal body volume, and we calculated a volume ratio between eventrated organ volume and intraabdominal volume (E/I ratio).

RESULTS

Primary closure was conducted in 13 cases and silo bag treatment with delayed closure in 9 cases. Prenatal MRI volumetry showed a significantly higher E/I ratio in patients with silo bag treatment with delayed closure (mean [M]=0.34; 95% confidence interval [CI] 0.30, 0.40) than in primary closure (M=0.23, 95% CI 0.19, 0.27; P=0.004). We propose a volume ratio cutoff value of 0.27 for predicting silo bag treatment.

CONCLUSION

Fetal MRI predicted silo bag treatment in patients with gastroschisis in 90% of the cases in our cohort and might facilitate prenatal counseling and treatment planning.

Prenatal assessment of congenital diaphragmatic hernia at north american fetal therapy network centers: A continued plea for standardization

INTRODUCTION

Prenatal work-up for congenital diaphragmatic hernia (CDH) is important for risk stratification, standardization, counseling, and optimal therapeutic choice. To determine current practice patterns regarding prenatal CDH work-up, including prenatal ultrasound and magnetic resonance imaging (MRI) use, and to identify areas for standardization of such evaluation between fetal centers.

METHODS

A survey regarding prenatal CDH work-up was sent to each member center of the North American Fetal Therapy Network (NAFTNet) (n = 36).

RESULTS

All responded. Sonographic measurement of lung-to-head ratio (LHR) was determined by all, 89% (32/36) of which routinely calculate observed-to-expected LHR. The method for measuring LHR varied: 58% (21/36) used a "trace" method, 25% (9/36) used "longest axis," and 17% (6/36) used an "antero-posterior" method. Fetal MRI was routinely used in 78% (28/36) of centers, but there was significant variability in fetal lung volume measurement. Whereas all generated a total fetal lung volume, the planes, methodology and references values varied significantly. All evaluated liver position, 71% (20/28) evaluated stomach position and 54% (15/28) quantified the degree of liver herniation. More consistency in workup was seen between centers offering fetal intervention.

CONCLUSION

Prenatal CDH work-up and management differs considerably among North American fetal diagnostic centers, highlighting a need for its standardization.

Prenatal diagnosis, imaging, and prognosis in Congenital Diaphragmatic Hernia

Antenatal ultrasound screening identifies more than 60% of Congenital Diaphragmatic Hernia (CDH) cases and provides the opportunity for in utero referral to a tertiary care center for expert assessment and perinatal management. Prenatal assessment of fetuses with CDH has tremendously improved over the past ten years. The outcome may be predicted prenatally by medical imaging and advanced genetic testing. The combination of lung size and liver position determination by ultrasound measurements and MRI are widely accepted methods to stratify fetuses into groups that correlate not only with neonatal mortality but also with morbidity. Notwithstanding this, prediction of persistent pulmonary hypertension of the newborn still needs to be improved.

Prediction tools in congenital diaphragmatic hernia

Because congenital diaphragmatic hernia (CDH) is characterized by a spectrum of severity, risk stratification is an essential component of care. In both the prenatal and postnatal periods, accurate prediction of outcomes may inform clinical decision-making, care planning, and resource allocation. This review examines the history and utility of the most well-established risk prediction tools currently available, and provides recommendations for their optimal use in the management of CDH patients.