Fetal MRI of the central nervous system: State-of-the-art

Prenatal ultrasonographic ( US) examination is considered as the first tool in the assessment of fetal abnormalities. However, several large- scale studies point out that some malformations, in particular central nervous system ( CNS) anomalies, are not well characterized through US. Therefore, the actual malformation severity is not always related to prenatal ultrasound ( US) findings. Over the past 20 years, ultrafast Magnetic Resonance Imaging ( MRI) has progressively increased as a prenatal 3rd level diagnostic technique with a good sensitivity, particularly for the study of fetal CNS malformations. In fact, CNS anomalies are the most common clinical indications for fetal MRI, representing about 80% of the total examinations. This review covers the recent literature on fetal brain MRI, with emphasis on techniques, safety and indications.