Ex-Vivo MRI of the Normal Human Placenta: Structural-Functional Interplay and the Association With Birth Weight

Area of Science:

• Medical Imaging
• Obstetrics & Gynecology
• Fetal Medicine

Background:

• Advanced magnetic resonance imaging (MRI) is crucial for human placenta assessment.
• Understanding the structure-function relationship in normal placentas is vital for identifying pregnancy risks.

Purpose of the Study:

• To characterize normal placental structure (volume, umbilical cord centricity index [CI]) and function (perfusion) ex-vivo using MRI.
• To assess the association between placental characteristics and birth weight (BW).
• To identify imaging markers for placentas at risk of dysfunction.

Main Methods:

• Utilized 3T MRI with T1/T2 weighted, 3D susceptibility-weighted, and time-resolved angiography with interleaved stochastic trajectories (TWIST) sequences.
• Employed an MRI-compatible perfusion system to mimic placental blood flow.
• Quantified placental volume, CI, and perfusion parameters (bolus arrival time, full-width at half maximum) from MRI data.

Main Results:

• Significant correlations were observed between placental perfusion parameters and CI (mean R = 0.72 ± 0.05).
• Birth weight correlated with placental volume (R = 0.62) and local perfusion asymmetry (R = -0.71).
• Placental function demonstrated a gradient associated with CI.

Conclusions:

• Ex-vivo MRI can characterize placental structure and function.
• Identified potential imaging markers indicating increased risk for placental dysfunction.
• Results suggest MRI can aid in assessing placental health and pregnancy outcomes.