How to obtain diagnostic planes of the fetal central nervous system using three-dimensional ultrasound and a context-preserving rendering technology.

The antenatal evaluation of the fetal central nervous system (CNS) is among the most difficult tasks of prenatal ultrasound (US), requiring technical skills in relation to ultrasound and image acquisition as well as knowledge of CNS anatomy and how this changes with gestation. According to the International Guidelines for fetal neurosonology, the basic assessment of fetal CNS is most frequently performed on the axial planes, whereas the coronal and sagittal planes are required for the multiplanar evaluation of the CNS within the context of fetal neurosonology. It can be even more technically challenging to obtain "nonaxial" views with 2-dimensional (2D) US. The modality of 3-dimensional (3D) US has been suggested as a panacea to overcome the technical difficulties of achieving nonaxial views. The lack of familiarity of most sonologists with the use of 3D US and its related processing techniques may preclude its use even where it could play an important role in complementing antenatal 2D US assessment. Furthermore, once a 3D volume has been acquired, proprietary software allows it to be processed in different ways, leading to multiple ways of displaying and analyzing the same anatomical imaging or plane. These are difficult to learn and time consuming in the absence of specific training. In this article, we describe the key steps for volume acquisition of a 3D US volume, manipulation, and processing with reference to images of the fetal CNS, using a newly developed context-preserving rendering technique.

Etiology and Prognosis of Severe Ventriculomegaly Diagnosed at Late Gestation.

OBJECTIVES: We sought to assess the causes and outcomes of severe VM diagnosed de novo after 24 weeks of gestation where a mid-trimester anomaly scan was described as normal. METHODS: Multicenter retrospective study of five European fetal medicine centers. The inclusion criteria were normal anatomy at the mid-trimester scan, uni/bilateral finding of posterior ventricle measuring ≥ 15 mm after 24 weeks with neonatal and postnatal pediatric and/or neurological assessment data. RESULTS: Of 74 potentially eligible cases, 10 underwent termination, the outcome was missing in 19 cases and there was 1 neonatal death. Therefore, 44 formed the study cohort with a median gestation at diagnosis of 32 + 0 weeks (25 + 6 - 40 + 5). VM was unilateral in five cases. Agenesis of the corpus callosum (ACC) and grade III/IV intraventricular hemorrhage (IVH) accounted for 14 cases each. ACC was isolated in 9 fetuses. Obstructive abnormalities included 5 arachnoid and 1 cavum velum interpositum cyst. Four fetuses had an associated suspected or confirmed genetic condition, 2 congenital infections, 1 abnormal cortical development and the etiology was unknown in 3/44. Postnatal assessment at median 20 months (3 - 96) showed 22/44 (50 %) normal, 7 (16 %) mildly abnormal and 15 (34 %) severely abnormal neurodevelopmental outcomes. CONCLUSION: One half of babies with severe VM diagnosed after 24 weeks have normal infant outcome with ACC and IVH representing the most common causes. Etiology is the most important factor affecting the prognosis of fetuses with severe VM diagnosed at late gestation.

Hemispheric surgery in children with refractory epilepsy: seizure outcome, complications, and adaptive function.

PURPOSE: To describe seizure control, complications, adaptive function and language skills following hemispheric surgery for epilepsy. METHODS: Retrospective chart review of patients who underwent hemispheric surgery from July 1993 to June 2004 with a minimum follow-up of 12 months. RESULTS: The study population comprised 24 children, median age at seizure onset six months and median age at surgery 41 months. Etiology included malformations of cortical development (7), infarction (7), Sturge-Weber Syndrome (6), and Rasmussen's encephalitis (4). The most frequent complication was intraoperative bleeding (17 transfused). Age <2 yr, weight <11 kg, and hemidecortication were risk factors for transfusion. Postoperative complications included aseptic meningitis (6), and hydrocephalus (3). At median follow-up of 7 yr, 79% of patients are seizure free. Children with malformations of cortical development and Rasmussen's encephalitis were more likely to have ongoing seizures. Overall adaptive function scores were low, but relative strengths in verbal abilities were observed. Shorter duration of epilepsy prior to surgery was related significantly to better adaptive functioning. CONCLUSIONS: Hemispheric surgery is an effective therapy for refractory epilepsy in children. The most common complication was bleeding. Duration of epilepsy prior to surgery is an important factor in determining adaptive outcome.