Purpose or Case Report: There is a widespread lack of familiarity with the normal appearance of the fetal brain in the early second trimester (12-18 weeks), particularly in MRI. Interpreting these images is challenging because of the continuous fetal motion, small size of structures, and immature appearance of the brain. This educational exhibit aims to increase awareness of the appearance of the fetal brain between 12- and 18-weeks gestation by presenting images of normal fetuses and establishing a correlation with same day ultrasound. All fetuses included in this exhibit were proven to have normal brains on late gestation fetal and/or post-natal brain MRI.

After viewing this exhibit the reader will (1) recognize the normal appearance of the brain in the early second trimester, (2) understand the specific developmental trajectories of major structures (ventricles, corpus callosum, etc…), (3) establish a correlation between the sonographic appearance and the fetal MRI.
Methods & Materials:
Results:
Conclusions: Acquiring and interpreting fetal MRI in the early 2nd trimester is challenging. Imaging can help identify major malformations and destructive injuries, such as semilobar or alobar holoprosencephaly, hydranencephaly or encephalocele. Confirming the integrity of small structures, such as the corpus callosum or brainstem, is difficult before 16 weeks. It is vital to recognize normal MRI appearance in the early 2nd trimester brain development to avoid misdiagnosis.