Evaluation of Placental Oxygenation in BOLD MRI Analysis Using Image Registration

Abstract

Fetal Growth Restriction (FGR) is an obstetric and gynecological disease. It causes fetal growth delay during gestation, resulting in a smaller fetal weight and increasing the risk of prenatal and postnatal health problems. Recently, some studies have reported that fetal growth is related to placental oxygenation. BOLD MRI visualizes oxygenation noninvasively and is expected to evaluate placental oxygenation and diagnose FGR. However, manual annotation of the placental region is a heavy burden on specialists to diagnose using BOLD MRI. This study proposes a method to reduce the annotation workload by applying image registration. The proposed method reduced the annotation workload to 1 time in 2D+t images, and the Dice coefficient of the aligned images and the ground truth mask was 0.779. This result beats the deep learning-based method without manual annotation with a Dice coefficient of 0.429. The proposed method is expected to be used for the evaluation of placental oxygenation and FGR diagnosis.