High-Fidelity T2 Relaxometry of the Developing Fetal Brain Using an 8-Second Single-Shot Multiple Overlapping-Echo...

Area of Science:

• Neuroimaging
• Biomarkers
• Fetal Development

Background:

• Quantitative MRI offers objective biomarkers for fetal brain maturation.
• Fetal movement during MRI acquisition poses a significant challenge to data quality.
• Developing motion-robust techniques is crucial for in utero assessment.

Purpose of the Study:

• To evaluate single-shot multiple overlapping-echo detachment (MOLED) imaging for fetal brain T2 relaxometry.
• To quantify fetal brain maturation by measuring T2 relaxation time in vivo.
• To assess the motion robustness and repeatability of MOLED T2 relaxometry.

Main Methods:

• Phantom and prospective in vivo studies were conducted using 3T MRI.
• Single-shot multiple overlapping-echo detachment (MOLED) and HASTE sequences were utilized.
• T2 relaxation time was measured in fetal white matter, deep gray matter, and brainstem across 52 fetuses (23-37 weeks GA).

Main Results:

• MOLED T2 relaxometry demonstrated high accuracy (r=0.99) and motion robustness compared to reference T2 values.
• Scan-rescan repeatability was excellent, with non-significant mean T2 differences (<1%).
• Significant negative correlations between regional T2 values and gestational age were observed, with the brainstem showing a higher rate of T2 change.

Conclusions:

• Single-shot multiple overlapping-echo detachment (MOLED) imaging provides motion-robust, repeatable, and clinically feasible T2 measurements of the fetal brain.
• Regional differences in T2 values and their age-related changes indicate the potential of MOLED for quantifying in utero brain maturation.
• This technique facilitates objective assessment of fetal neurodevelopmental trajectories.