Development of fetal brain sulci and gyri: assessment through two and three-dimensional ultrasound and magnetic resonance imaging.

BACKGROUND: Cerebral malformations may lead to permanent postnatal sequels. The antenatal detection of anomalous or absent fetal sulci and gyri may indicate abnormal brain development and future neurological and psychomotor problems in that infant. The prenatal diagnosis of these conditions allows genetic counseling, psychological support of the parents and optimization of obstetric management. Diagnosis is usually based on two-dimensional obstetric ultrasound (2DUS) and eventually fetal magnetic resonance imaging (MRI), to confirm findings. Fetal three-dimensional ultrasound (3DUS) using the rendering mode has been recently introduced but has not yet been extensively tested in clinical practice. CONTEXT: This study reviewed and compared three imaging modalities, 2DUS, 3DUS, and MRI, in the analysis of the development of the main sulci and gyri of central nervous system of normal fetuses between 20 and 32 weeks' gestation.