The prevalence and the adding value of fetal MRI imaging in midline cerebral anomalies

Background Foetal MR imaging is widely accepted as an adjunct to foetal ultrasonography; however, there are many controversies regarding its importance and indications. Therefore, this study aimed to evaluate foetuses with different midline cerebral abnormalities, to determine the prevalence of these anomalies, to define the role of foetal MRI, and to compare MRI and ultrasound (US) result with postnatal MRI findings. Seventy-eight pregnant women who had foetuses with CNS abnormalities detected by sonogram were included. Foetuses with midline anomalies were selected and evaluated by anomaly scan foetal US, pre- and postnatal MRI. Results Midline brain anomalies were found in 47.4% of foetuses with brain anomalies. Holoprosencephaly was found in 24.3% of midline anomaly foetuses, corpus callosum abnormalities (ACC) were detected in 40.5%, midline intracranial mass lesions in 2.7%, and midline posterior fossa anomalies in 32.4%. An agreement between MRI and US in the main diagnosis was in 56.76% of cases; MRI added information to US findings in 43.2% of cases, and US added information to MRI findings in 8.1% of cases. Conclusion In evaluating midline cerebral anomalies, US and MRI are complementary techniques. US is the primary survey, and MRI can add additional information and/or change the main diagnosis.