Meeting Banner
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.

Keywords

absolute active affects animals arteries artery believed better biophysics blood bold brain broad cerebral characterize characterized children circulation comprehensive condition conditions consistent content control controlled cycling dams days decreased dependent developing diagnostic direct directed dysfunction essential expense false feasible fetal fetus fetuses findings flow function gestation gradient growth healthy help highly horizontal hospital human humans hypoxia impaired increasing inhaled inspired intensity invasive john journal late lead liver magnet materials maternal measure measured measures measuring mechanically medical mice mike mixture modality model models monitoring mortality mouse negatives noninvasive normalized novel obstetrics occurs often opportunities orange organs outcome oxygen oxygenated oxygenation particularly pediatrics perinatal physiology placed placenta placental placentas plateau posterior predicting pregnancies pregnant presently preserve procedures prone proportion radiology redistribution reduced regulation representative resolution respectively response rise risk seed severe sheep sick simulated sled slice sparing spine studied studies supply survival therapies tool ultrasound umbilical understanding valuable varied velocity ventilated vessels whereby