Cotyledon-Specific Flow Evaluation of Rhesus Macaque Placental Injury Using Ferumoxytol Dynamic Contrast-Enhanced MRI

Area of Science:

• Biomedical Imaging
• Magnetic Resonance Imaging
• Placental Physiology

Background:

• Dynamic contrast-enhanced (DCE) MRI with ferumoxytol enables noninvasive assessment of placental structure and function.
• Previous studies have not evaluated DCE MRI under pathological placental conditions.

Purpose of the Study:

• To measure cotyledon-specific placental blood flow in rhesus macaques using ferumoxytol DCE MRI.
• To establish a novel animal model for inducing and assessing local placental injury.

Main Methods:

• A prospective animal model using 11 rhesus macaque pregnancies.
• Induction of placental injury via injections of Tisseel or monocyte chemoattractant protein 1.
• Ferumoxytol DCE MRI scans performed at multiple gestational time points (GD 100, 115, 145) using a 3T scanner and T1-weighted spoiled gradient echo sequence.

Main Results:

• Ferumoxytol DCE MRI enabled measurement of cotyledon-specific volume, flow, and normalized flow.
• Significantly reduced cotyledon volume, flow, and normalized flow were observed in macaques receiving 1.5 mL Tisseel at GD 145.
• Histopathology confirmed tissue necrosis in Tisseel-treated animals, correlating with imaging findings.

Conclusions:

• Ferumoxytol-enhanced DCE MRI is feasible for cotyledon-specific functional analysis in a placental injury model.
• The technique can detect placental injury and functional changes at multiple gestational time points.
• This rhesus macaque model provides a valuable platform for studying placental pathology using advanced MRI techniques.