Cerebral biometry in fetal magnetic resonance imaging: new reference data

Area of Science:

• Neuroimaging
• Fetal Medicine
• Medical Biometry

Background:

• Accurate fetal biometry is crucial for monitoring fetal development and detecting abnormalities.
• Magnetic resonance imaging (MRI) offers detailed visualization of the fetal brain, but standardized reference data are needed.

Purpose of the Study:

• To establish normal reference biometric data for the fetal brain using MRI.
• To assess the reproducibility of fetal brain MRI measurements.
• To evaluate potential gender-specific differences and compare MRI with ultrasound biometry.

Main Methods:

• Prospective collection of normal fetal brain MRI examinations from 589 fetuses (26-40 weeks' gestation).
• Measurement of key parameters including supratentorial space, corpus callosum length, cerebellar vermis dimensions, and pons diameter.
• Evaluation of interobserver reproducibility, gender effects, hemispheric symmetry, and comparison with ultrasound biometry.

Main Results:

• Normal reference values (3rd-97th percentile) were established for all measured fetal brain parameters.
• Excellent interobserver agreement (Intraclass Correlation Coefficient > 0.75) was demonstrated for most measurements.
• No clinically significant gender-related differences were found. MRI and ultrasound measurements showed excellent agreement (ICC = 0.85 for BPD, ICC = 0.85 for TCD).

Conclusions:

• New, reproducible reference charts for fetal cerebral MRI biometry (26-40 weeks' gestation) have been generated from a large cohort.
• These data provide a reliable resource for clinical assessment and research in fetal neurodevelopment.
• The findings support the integration of fetal MRI biometry into routine obstetric practice due to its reproducibility and agreement with ultrasound.