Longitudinal analysis of fetal MRI in patients with prenatal spina bifida repair

TL;DR

This study introduces a fetal MRI analysis pipeline to longitudinally assess brain development in fetuses with spina bifida, revealing ventricle growth patterns and the effects of prenatal repair.

Contribution

The paper presents a novel automated MRI analysis pipeline including ventricle segmentation and morphometry for fetuses with SB, enabling detailed longitudinal brain development studies.

Findings

Ventricle enlargement was observed post-operatively.

Myeloschisis patients showed more ventriculomegaly progression.

Prenatal ventricle volume growth was quantified.

Abstract

Open spina bifida (SB) is one of the most common congenital defects and can lead to impaired brain development. Emerging fetal surgery methods have shown considerable success in the treatment of patients with this severe anomaly. Afterwards, alterations in the brain development of these fetuses have been observed. Currently no longitudinal studies exist to show the effect of fetal surgery on brain development. In this work, we present a fetal MRI neuro-imaging analysis pipeline for fetuses with SB, including automated fetal ventricle segmentation and deformation-based morphometry, and demonstrate its applicability with an analysis of ventricle enlargement in fetuses with SB. Using a robust super-resolution algorithm, we reconstructed fetal brains at both pre-operative and post-operative time points and trained a U-Net CNN in order to automatically segment the ventricles. We investigated the change of ventricle shape post-operatively, and the impacts of lesion size, type, and GA at operation on the change in ventricle shape. No impact was found, except for moderately larger ventriculomegaly progression in myeloschisis patients. Prenatal ventricle volume growth was also investigated. Our method allows for the quantification of longitudinal morphological changes to fully quantify the impact of prenatal SB repair and could be applied to predict postnatal outcomes.