Abstract #2326

Brain Sparing in Fetal Mice: Using BOLD MRI to Study Blood Redistribution During Hypoxia

Lindsay S. Cahill¹, Yu-Qing Zhou¹, Mike Seed, Christopher K. Macgowan,², John G. Sled¹,²

¹Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada; ²Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada

Fetal growth restriction is often associated with brain sparing whereby a greater proportion of oxygenated fetal blood is directed to the brain at the expense of other organs. Understanding the physiology of this response may lead to better diagnostic procedures for predicting fetal risk. Here, BOLD MRI contrast is used to characterize the redistribution of fetal blood flow that occurs in mice under hypoxic conditions. As the maternal inspired gas mixture is varied, large BOLD signal changes were observed in the fetal liver but not in the brain. Using Doppler ultrasound, cerebral blood flow was observed to rise under hypoxia.