Prenatal diagnosis of spinal dysraphism.

INTRODUCTION: Since intrauterine repair of open spinal dysraphism have demonstrated promising results, it has become crucial to accurately define the various prenatal pathologies. The embryogenesis of spinal dysraphism according to a clinical neuroradiological classification is reviewed, with special emphasis on the recent advances in prenatal ultrasound (US), such as high-frequency linear transducers and three-dimensional imaging. FUNDINGS: The role of magnetic resonance imaging (MRI) of the fetus as a complementary tool for delineating complex fetal spinal anomalies and further defining associated central nervous system (CNS) anomalies is explored. Differentiation between normal appearance of the fetal spine and the wide range of congenital neural tube defects are demonstrated in both modalities with special emphasis on their complementary role in the accurate diagnosis of neural tube defects.