Fetal brain MRI findings and neonatal outcome of common diagnosis at a tertiary care center

Diverse childhood neurologic disorders and outcomes following fetal neurologic consultation

Fetal neurology encompasses the full spectrum of neonatal and child neurology presentations, with complex additional layers of diagnostic and prognostic challenges unique to the specific prenatal consultation. Diverse genetic and acquired etiologies with a range of potential outcomes may be encountered. Three clinical case presentations are discussed that highlight how postnatal phenotyping and longitudinal follow-up are essential to address the uncertainties that arise in utero, after birth, and in childhood, as well as to provide continuity of care.

One model, two brains: Automatic fetal brain extraction from MR images of twins

Fetal brain extraction from magnetic resonance (MR) images is of great importance for both clinical applications and neuroscience studies. However, it is a challenging task, especially when dealing with twins, which are commonly existing in pregnancy. Currently, there is no brain extraction method dedicated to twins, raising significant demand to develop an effective twin fetal brain extraction method. To this end, we propose the first twin fetal brain extraction framework, which possesses three novel features. First, to narrow down the region of interest and preserve structural information between the two brains in twin fetal MR images, we take advantage of an advanced object detector to locate all the brains in twin fetal MR images at once. Second, we propose a Twin Fetal Brain Extraction Network (TFBE-Net) to further suppress insignificant features for segmenting brain regions. Finally, we propose a Two-step Training Strategy (TTS) to learn correlation features of the single fetal brain for further improving the performance of TFBE-Net. We validate the proposed framework on a twin fetal brain dataset. The experiments show that our framework achieves promising performance on both quantitative and qualitative evaluations, and outperforms state-of-the-art methods for fetal brain extraction.

Funcmasker-flex: An Automated BIDS-App for Brain Segmentation of Human Fetal Functional MRI data

Fetal functional magnetic resonance imaging (fMRI) offers critical insight into the developing brain and could aid in predicting developmental outcomes. As the fetal brain is surrounded by heterogeneous tissue, it is not possible to use adult- or child-based segmentation toolboxes. Manually-segmented masks can be used to extract the fetal brain; however, this comes at significant time costs. Here, we present a new BIDS App for masking fetal fMRI, funcmasker-flex, that overcomes these issues with a robust 3D convolutional neural network (U-net) architecture implemented in an extensible and transparent Snakemake workflow. Open-access fetal fMRI data with manual brain masks from 159 fetuses (1103 total volumes) were used for training and testing the U-net model. We also tested generalizability of the model using 82 locally acquired functional scans from 19 fetuses, which included over 2300 manually segmented volumes. Dice metrics were used to compare performance of funcmasker-flex to the ground truth manually segmented volumes, and segmentations were consistently robust (all Dice metrics ≥ 0.74). The tool is freely available and can be applied to any BIDS dataset containing fetal bold sequences. Funcmasker-flex reduces the need for manual segmentation, even when applied to novel fetal functional datasets, resulting in significant time-cost savings for performing fetal fMRI analysis.

Institutional Evaluation of Fetal Neurology Consults and Postnatal Outcomes: A 10-Year Retrospective Cohort Review

Background and Objectives

An increasing number of centers are offering fetal neurology consultation services; however, there is limited information available in overall institutional experiences. Data are lacking on the fetal characteristics, pregnancy course, and the influence of fetal consultation on perinatal outcomes. The aim of this study is to provide insight on the institutional fetal neurology consult process and areas of strengths and weaknesses.

Methods

We performed a retrospective electronic chart review of fetal consults from April 2, 2009, to August 8, 2019, at Nationwide Children's Hospital. The objectives were to summarize clinical characteristics, agreement of prenatal and postnatal diagnoses based on best available imaging, and postnatal outcomes.

Results

Of the 174 maternal-fetal neurology consults placed, 130 qualified for inclusion based on data available for review. Of the 131 anticipated fetuses, 5 experienced fetal demise, 7 underwent elective termination, and 10 died in the postnatal period. The majority were admitted to the neonatal intensive care unit; 34 (31%) required supportive intervention for feeding, breathing, or hydrocephalus, and 10 (8%) experienced seizures during their neonatal intensive care unit (NICU) stay. Imaging results from 113 babies who had prenatal and postnatal imaging of the brain were analyzed based on the primary diagnosis. The most common malformations were as follows (prenatal % vs postnatal %): midline anomalies (37% vs 29%), posterior fossa abnormalities (26% vs 18%), and ventriculomegaly (14% vs 8%). Additional disorders of neuronal migration were not seen on fetal imaging but were present in 9% of the postnatal studies. Analysis of agreement between prenatal and postnatal diagnostic imaging for the 95 babies who had MRIs at both time points found moderate concordance (Cohen kappa: 0.62, 95% CI 0.5-0.73; percent agreement: 69%, 95% CI 60%-78%). Consult recommendations for neonatal blood tests affected postnatal care in 64 of 73 cases in which the infant survived and data were available.

Discussion

Establishing a multidisciplinary fetal clinic can provide timely counseling and create rapport with families to have continuity of care for birth planning and postnatal management. Prognosis based on radiographic prenatal diagnosis requires caution as some neonatal outcomes may vary considerably.

Evaluation of Posterior Fossa Biometric Measurements on Fetal MRI in the Evaluation of Dandy-Walker Continuum

BACKGROUND AND PURPOSE

Dandy-Walker malformation, vermian hypoplasia, and Blake pouch remnant represent a continuum of anomalies and are common reasons for referral for fetal MR imaging. This study aimed to determine biometric measurements that quantitatively delineate these 3 posterior fossa phenotypes.

MATERIALS AND METHODS

Our single-center institutional review board approved a retrospective analysis of all fetal MRIs for posterior fossa malformations, including Dandy-Walker malformation, vermian hypoplasia, and Blake pouch remnant. Measurements included the anterior-to-posterior pons, craniocaudal and anterior-to-posterior vermis, lateral ventricle size, and tegmentovermian and posterior fossa angles. Measurements were compared with normal biometry and also between each subgroup.

RESULTS

Thirty-three fetuses met the criteria and were included in the study. Seven were designated as having Dandy-Walker malformation; 16, vermian hypoplasia; and 10, Blake pouch remnant. No significant group interactions with adjusted mean gestational age for tegmentovermian and posterior fossa angles were observed. The tegmentovermian angle was significantly higher in Dandy-Walker malformation (109.5° [SD, 20.2°]) compared with vermian hypoplasia (52.13° [SD, 18.8°]) and Blake pouch remnant (32.1° [SD, 17.9°]), regardless of gestational age. Lateral ventricle sizes were significantly higher in Dandy-Walker malformation at a mean of ≥23.1 weeks' gestational age compared with vermian hypoplasia and Blake pouch remnant. The anterior-to-posterior and craniocaudal vermes were significantly smaller in Dandy-Walker malformation compared with vermian hypoplasia and Blake pouch remnant at mean of ≥23.1 weeks' gestational age.

CONCLUSIONS

Dandy-Walker malformation can be described in relation to vermian hypoplasia and Blake pouch remnant by an increased tegmentovermian angle; however, other potential qualifying biometric measurements are more helpful at ≥23.1 weeks' gestational age. Because they fall along the same spectrum of abnormalities, the difficulty in distinguishing these entities from one another makes precise morphologic and biometric descriptions important.

Agreement between prenatal ultrasound and 3.0T magnetic resonance imaging in the assessment of anomalies of the central nervous system: A single-center experience in Slovakia

OBJECTIVE

To assess the concordance of in-utero magnetic resonance imaging (MRI) findings at 3.0T in fetuses with suspect abnormalities of the central nervous system (CNS) on ultrasonography.

METHODS

A retrospective study was done on 222 pregnant women indicated for fetal MRI, with the examination performed within 2 weeks from indication. The inclusion criteria for patients were age 18 years or older with the fetus at 18 weeks of gestation or more. Fetal CNS pathologies were divided into six categories: ventriculomegaly; supratentorial midline abnormalities (ACC); supratentorial space-occupying lesions; abnormalities of the posterior fossa; destructive cerebral lesions; and cortical formation abnormalities (CFA). Chance-adjusted agreement was assessed using unweighted Cohen's kappa (κ).

RESULTS

The best agreement between ultrasound and MRI was observed in ventriculomegaly (κ=0.817; 95% confidence interval [CI] 0.76-0.88). There was only a moderate agreement in ACC (κ=0.483; 95% CI 0.35-0.61). CFA pathologies had a poor agreement between the modalities (κ=0.140; 95% CI -0.03 to 0.31).

CONCLUSION

Ultrasonography has good overall agreement with MRI in diagnosing fetal CNS anomalies. CFA had the most disagreement between ultrasound and MRI. The prognostic implication of these findings can be used for parental neuro-counseling but should be investigated further.