Three-dimensional neurosonography — a novel field in fetal medicine

Abstract

Neurosonography is a promising technique for prenatal diagnosis, combining features of ultrasound imaging with fetal neurology. The brain is a three-dimensional structure, therefore observing brain structure in the three basic planes (sagittal, coronal and axial) is mandatory. The anterior fontanelle and sagittal suture may serve as acoustic ultrasound windows in the transvaginal brain scan, allowing to obtain high-resolution neuroimages of the intracranial structures. Furthermore, three-dimensional (3D) ultrasound combined with the transvaginal brain approach provides detailed and sophisticated neuroimages. Three orthogonal planes of the brain, tomographic ultrasound imaging (TUI) and other off-line approaches (e.g. volume contrast imaging (VCI) or HDlive silhouette imaging) may be obtained from a single 3D dataset. 3D Doppler ultrasound enables visualization of the intracerebral vascularity, allowing to obtain more precise information on cerebral perfusion. Various abnormal brain conditions, including ventriculomegaly, agenesis of the corpus callosum, posterior fossa abnormalities and others, can be well-demonstrated. Due to high rates of the associated anomalies and uncertain prognosis, any suspicion of CNS abnormalities shall imply detailed ultrasonographic evaluation of the fetal anatomy to exclude the associated anomalies. Despite a growing number of neuroimaging modalities, prenatal counselling remains a challenge as prediction of brain functionality and the neurological prognosis often remain uncertain. New investigations on the relations between various migration disorders and gene mutations, as well as recent clinical research on the relations between neuroimaging detection of local migration disorders using sophisticated imaging technologies and the postnatal neurological prognosis will contribute to the development of maternal-fetal medicine as well as pediatric neurology.