Efficient fetal brain and placental T1 mapping at 0.55T

Fetal MRI provides crucial anatomical and functional information. At low field it could benefit from reduced distortion, increased bore size and increased B1 homogeneity. T1 contrast and mapping in the fetal brain provides complementary information for example for haemorrhages, infarcts and in placental disease. Here, a low-field (0.55T) fetal T1 inversion-recovery EPI-based sequence benefiting from the lower T1 and hence higher efficiency is demonstrated for placenta and brain in a cohort of pregnant participants including two clinical cases. Significant correlation with gestational age is demonstrated (p<0.05) and high quality maps allowing sub-regions analysis in the brain are shown.