Prenatal magnetic resonance imaging: brain normal linear biometric values below 24 gestational weeks

Area of Science:

• Neuroimaging
• Developmental Biology
• Medical Statistics

Background:

• Prenatal magnetic resonance (MR) imaging is vital for assessing fetal brain structural development.
• Current morphometric studies primarily focus on the third trimester.
• Limited normative data exists for fetal brain development between 20-24 weeks gestation, a critical period due to legal restrictions on abortion timing.

Purpose of the Study:

• To establish accurate and reliable normative data for fetal brain structures between 20-24 weeks gestation.
• To provide practical parametric support for assessing these normative data.
• To address the lack of established reference ranges for early second-trimester fetal brain development.

Main Methods:

• Retrospective analysis of 84 normal fetal MR imaging studies (20-24 weeks gestation).
• Exclusion of fetuses with infections, twin pregnancies, or maternal pathologies affecting growth.
• Linear biometrical measurements of cerebral structures performed by three experienced pediatric neuroradiologists.

Main Results:

• Substantial interobserver agreement achieved for all measurements.
• Normative data, including median, maximum, and minimum values, were successfully obtained for key brain structures.
• Established a reliable dataset for early second-trimester fetal brain biometry.

Conclusions:

• Knowledge of normative ranges and interindividual variability is essential for evaluating fetal brain development.
• This data is valuable for clinical settings in assessing normal brain development in fetuses aged 20-24 weeks.
• Facilitates early identification of potential developmental abnormalities.