Placental pathologies in fetal MRI with pathohistological correlation

Area of Science:

• Medical Imaging
• Obstetrics and Gynecology
• Pathology

Background:

• Fetal Magnetic Resonance Imaging (MRI) is increasingly used in prenatal diagnostics.
• Assessing placental pathologies with fetal MRI is crucial for managing pregnancy complications.
• Current MRI techniques' sufficiency for evaluating placental abnormalities requires validation against histological findings.

Purpose of the Study:

• To evaluate the efficacy of current fetal MRI techniques in diagnosing placental pathologies.
• To determine the correlation between MRI-detected placental abnormalities and subsequent histopathological findings.
• To assess fetal MRI's potential as a tool for evaluating placental insufficiency.

Main Methods:

• Retrospective analysis of 45 singleton pregnancies with diagnosed placental pathologies on MRI (19-35 weeks gestation).
• Standardized MRI protocol on a 1.5T unit including T2-, T1-, diffusion-weighted, and echo-planar sequences.
• Categorization of pathologies (infarction, hemorrhage types, fibrin deposition, chorioamnionitis) and comparison with postnatal pathohistological examination (median 7 days post-MRI).

Main Results:

• Fetal MRI demonstrated high detection rates for placental infarctions (96.2%) and confirmed retroplacental hematomas.
• MRI identified 9 of 14 subchorionic hematomas and 6 of 8 intervillous hemorrhages.
• Chorioamnionitis and massive perivillous fibrin deposition showed limited signal changes on MRI, suggesting subtle macroscopic placental alterations.

Conclusions:

• Fetal MRI is effective in detecting placental hemorrhages and ischemic lesions.
• MRI shows promise for assessing placental insufficiency, though limitations exist for certain pathologies like chorioamnionitis.
• Further research may refine MRI protocols for improved detection of subtle placental changes.