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

- Fetal MRI is considered as the third diagnostic level tool after second level US, in the assessment of CNS anomalies.
- Fetal MRI is useful in presence of parental genetic disorders.
- Generally fetal MRI is performed using a 1.5T traditional superconducting magnet.
- The examination is recommended from 19 Gestational Age (GA).
- Fetal CNS study protocol includes primarily T2-, T1-WI and DWI sequences.

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.