Abstract #0572

Unique in Utero Identification of Fetuses in Multi-Fetal Mouse Pregnancies by Placental Bi-Directional Arterial Spin Labeling (BD-ASL) MRI

Reut Avni¹, Tal Raz¹, Joel Garbow², Michal Neeman¹

¹Biological Regulation, Weizmann Institute of Sceince, Rehovot, Israel; ²Biomedical MR Laboratory, Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO, United States

The study presented here examines whether natural occurring deaths, as well as genetic manipulation to create targeted defects in placental function (PKB/ Akt1-/- fetuses), affect placental perfusion and maternal blood volume in adjacent (normal) fetuses at late-gestation, as measured by in vivo Bi-Directional Arterial Spin Labeling (BD-ASL) MRI and ex vivo fluorescence microscopy, respectively. The ability to noninvasively determine fetal location along the uterine horn using BD-ASL method opens possibilities for determining and pursuing phenotypic alterations in genetic, as well as developmental, longitudinal studies. These data suggest in systems of multiple fetuses within one uterus there may exist communication mechanisms (e.g. hydrodynamic)