MRI Shows Promise for Assessing Intrauterine Fetal Lung Development

FETAL lung development could be monitored using MRI-based diffusion tensor imaging (DTI), with new research showing that several imaging measurements reflected normal lung maturation throughout pregnancy. The findings suggested DTI-derived measurements may serve as markers of fetal lung development, although further validation is needed before routine clinical use.

Fetal lung development is the process by which immature lung tissue develops into functional lungs before birth. This occurs through four recognised stages: pseudoglandular, canalicular, saccular and alveolar. Accurate assessment of these developmental changes is considered important for fetal health management.

MRI Measures Reflected Fetal Lung Development

The prospective study evaluated whether MRI-based DTI could assess normal fetal lungs and to determine whether DTI-derived measurements reflected developmental changes during gestation and had potential as markers of fetal lung development.

Researchers performed DTI in 84 pregnant women between 18 and 36 weeks’ gestation. Lung and liver regions of interest were identified on MRI images to calculate the lung-to-liver signal intensity ratio, while three-dimensional segmentation was used to measure fetal lung volume. Fractional anisotropy (FA) and mean diffusivity were also calculated from the DTI data before regression analysis examined how each imaging marker changed with gestational age.

Thirty-two participants were excluded because fetal motion produced imaging artefacts, leaving 52 pregnancies for analysis.

Across the left, right and combined lungs, FA, mean diffusivity, lung-to-liver signal intensity ratio and fetal lung volume showed significant correlations with gestational age (all P<0.01).

Fractional Anisotropy Shift Marked Lung Maturation

Among the DTI measures, FA showed the clearest change over time. FA declined markedly up to 29 weeks’ gestation, then remained relatively stable thereafter.

The researchers concluded that this pattern was consistent with microstructural changes occurring as the fetal lung matured and may reflect the transition from the canalicular stage to the saccular stage of development.

Findings Support Further Evaluation of MRI Biomarkers

The study was limited by the exclusion of 32 participants because fetal motion affected image quality, reducing the number of analysable scans.

Despite this limitation, the findings demonstrated that multiple MRI-derived measurements tracked fetal lung maturation across gestation. The findings supported the feasibility of DTI as a potential imaging biomarker for fetal lung development, although additional studies are needed to determine its role in clinical assessment.

Reference

Liu Q et al. Diffusion tensor magnetic resonance imaging of the normal fetal lung: a preliminary report. Pediatr Radiol. 2026;DOI:10.1007/s00247-026-06695-y.

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