MRI for Placenta Accreta Spectrum following Ferumoxytol Infusion (H-50859)

To determine whether Fe-MRI enhances visualization and mapping of extrauterine vascular changes associated with PAS, and predictive parameters of severe maternal morbidity: any transfusion, massive transfusion, need for vascular occlusion (embolization, aortic occlusion), extrauterine injury compared to standard of care imaging.