Fetal MRI in the evaluation of fetuses referred for sonographically suspected neural tube defects (NTDs): impact on diagnosis and management decision.

INTRODUCTION: We hypothesized that magnetic resonance imaging (MRI) can assess fetuses with sonographically (ultrasonography (US))-suspected neural tube defects (NTD) that might influence their diagnoses and management decision.
METHODS: Institutional review board approval and informed consents were obtained to perform MRI for 19 fetuses referred with US-suspected NTD. Prenatal imaging findings were correlated with management decision, postnatal clinical, postnatal imaging, and pathology.
RESULTS: Prenatal MRI correctly ruled out US diagnosis of cephalocele in a fetus. In the other 18 fetuses, MRI detected detailed topography and contents of NTD sacs in five, added central nervous system (CNS) abnormalities that were not apparent on US in three, and confirmed non-CNS findings in three fetuses. MRI changed diagnosis of 3/19 fetuses (15.8%), caused minor change in diagnosis of 5/19 (26.3%), and did not influence US diagnosis of 11/19 fetuses (57.9%). MRI findings changed/modified management decision in 21% of the fetuses.
CONCLUSION: Fetal MRI is an important adjunct to US in assessing NTD. It can identify topography and contents of sacs, add CNS and non-CNS findings, and influence management decision.