Conventional Fetal Mri

INTRODUCTION Fetal MRI is a safe, noninvasive way to image the developing fetal brain. In clinical practice, it is primarily performed for further evaluation of a suspected sonographic abnormality. Fetal MRI is also performed in conditions where prenatal sonography of the fetal brain is normal but the fetus is at increased risk for neurodevelopmental abnormalities. These include complications of twin pregnancy, such as twin-twin transfusion syndrome and cotwin demise, families with history of neurodevelopmental disorders, and certain maternal infections. Studies have consistently demonstrated that fetal MRI can identify additional brain abnormalities that are not detected by prenatal sonography. Moreover, this information influences counseling during the pregnancy. Because fetal MRI is affected by normal fetal motion, it is preferable to perform fetal MRI at more advanced gestational ages, such as in the mid 2 trimester or later. In the United States, fetal MRI is typically performed after 21 weeks gestation. In order to accurately detect abnormalities in brain development, knowledge of the appearance of the fetal brain at different gestational ages is required. Furthermore, familiarity with the appearance of different types of brain abnormalities in the neonatal/pediatric brain is also helpful.