We propose a novel platform technology based on liposomal MRI imaging agents that provide methodology for safe, facile vascular and molecular imaging of the placenta. We focus in this application on Morbidly Adherent Placenta (MAP: classified as placenta accreta, increta or percreta), and will demonstrate the power of this technology for the study of this condition, noting that the technology once developed will be applicable to numerous other placental conditions. Diagnosis of MAP remains challenging, even with ultrasound followed by MRI in indeterminate cases: only about half of the cases of MAP are suspected prior to childbirth15. MAP results in massive blood loss (25% of cases), hysterectomy (70% of cases) and ICU admission (30% of cases), at rates far higher than the non-‐MAP population. The detection of a “retroplacental clear space” is a marker of normal placentation. Further, the level of adrenomedullin and its receptor (the CRCLR/RAMP2 complex) is thought to be an early marker of MAP. The specific aims of this project are therefore 1. Quantify placental margin delineation with the liposomal Gd contrast agent, in rodent models. a. Test the visualization of the “retroplacental clear space”, a poorly vascularized layer between the placenta and the myometrial wall, as a measure of margin delineation, as a function of gestational age. b. Compare detection of the retroplacental clear space and placental margins with non-‐contrast MRI and conventional Gd chelates, through the course of gestation. 2. Test whether the spatial expression of the Adrenomedullin receptor (CRCLR/RAMP2) in the placenta and uterine wall correlate with placental invasion, across a range of gestational ages. a. Visualize and quantify CRCLR/RAMP2 with MRI using an adrenomedullin targeted Gd liposome, and validate using immunohistochemistry b. Correlate CRCLR/RAMP2 levels with imaging based margin delineation and histologically determined placental invasion throughout gestation.