3D VISUALISATION AND VOLUMETRIC ASSESSMENT OF THE FETAL LARGE BOWEL ACROSS GESTATION USING MRI: A PILOT...

Area of Science:

• Medical Imaging
• Fetal Medicine
• Gastroenterology

Background:

• Antenatal assessment of fetal bowel is challenging with current ultrasound limitations.
• Fetal MRI has been used, but 2D measurements lack comprehensive data, and advanced 3D techniques are emerging.
• Motion-corrected 3D MRI enables high-resolution analysis of fetal abdominal structures.

Purpose of the Study:

• To apply advanced 3D MRI techniques for fetal large bowel visualization and quantification.
• To generate high-resolution datasets for volumetric assessment of the fetal large bowel.
• To establish reference ranges for fetal large bowel volume throughout gestation.

Main Methods:

• Fetal MRI (3T, T2-weighted) was performed on 40 fetuses (16-38 weeks' gestation).
• Motion-correction pipelines created 3D reconstructions of the fetal abdomen and large bowel.
• Manual segmentation of five large bowel regions allowed for volumetric measurements and reproducibility assessment (ICC).

Main Results:

• The entire fetal large bowel was visualized in 100% of the 40 analyzed datasets.
• Intra- and inter-observer agreement for measurements were good to excellent.
• Fetal large bowel volume demonstrated a linear increase with gestational age, from 1266 cm³ at 18 weeks to 13,550 cm³ at 38 weeks.

Conclusions:

• 3D reconstruction and volumetric assessment of the fetal large bowel are feasible and reproducible.
• This advanced MRI technique enhances understanding of normal fetal bowel development.
• It holds potential for improved antenatal identification of fetal bowel pathologies.