Contribution of magnetic resonance imaging to ultrasound for the evaluation of fetal central nervous system anomalies

OBJECTIVE: To evaluate whether magnetic resonance imaging (MRI) contributes to ultrasound for the evaluation of fetal central nervous system (CNS) anomalies. The secondary objective was to investigate whether MRI adds more information regarding the evaluation of specific pathologies or conditions. STUDY DESIGN: We retrospectively compared fetal MRI findings with ultrasound findings in CNS anomalies with respect to certain pathologic groups. Additionally, we evaluated diagnostic accuracy by comparing fetal MRI and ultrasound findings with postnatal findings. RESULTS: A total of 34 patients had 40 provisional diagnoses by fetal ultrasound, and of those patients 14 had a provisional diagnosis of ventriculomegaly and 14 had a provisional diagnosis of cerebellar or posterior fossa anomalies. MRI added to or changed the diagnosis in 52.5% of the patients with CNS abnormalities. The contribution rate in ventriculomegaly was 71.4%, and MRI changed the diagnosis in all indefinite diagnoses by ultrasound. Additionally, of the 15 patients with postnatal findings, there were no cases in which only the ultrasound findings were correct, but the MRI findings were incorrect. CONCLUSION: MRI contributes to ultrasound in the diagnosis of CNS anomalies. Cases of indefinite diagnosis and ventriculomegaly by ultrasound had greater benefit from MRI.