Advances in paediatric CNS ultrasound

Gray-scale ultrasound findings of hypoxic-ischemic injury in term infants

Brain ultrasound has become a critical tool for bedside screening and monitoring of hypoxic-ischemic injury in infants. Transfontanellar ultrasound in infants allows delineation of anatomical structures of the brain and posterior fossa. The technique's low cost, lack of ionizing radiation and repeatability make it a popular alternative to magnetic resonance imaging. The published literature on interpreting hypoxic-ischemic injury on brain ultrasound is wide and varied, yet diagnostic challenges remain when detecting subtle or diffuse changes. This pictorial essay summarizes and illustrates the spectrum of sonographic findings of hypoxic-ischemic injuries in term infants.

Head Ultrasound and MR imaging in the evaluation of neonatal encephalopathy: competitive or complementary imaging studies?

Magnetic resonance (MR) imaging is superior to ultrasonography (US) for the evaluation and prognostication of neonates with neonatal encephalopathy (NE). Nonetheless, US may provide important information early in the course of NE and can be used to document the evolution of lesions. This article provides an overview of useful findings in the US evaluation of infants with NE. Although many of the findings do not appear as conspicuous or as extensively as they do on MR imaging, recognition and familiarity with subtle head US abnormalities may allow head US to play an important complementary role to MR imaging in the evaluation of infants with NE.

Intracranial hemorrhage in newborns with hemophilia: the role of screening radiologic studies in the first 7 days of life

In newborns with hemophilia, intracranial hemorrhage (ICH) is a potentially life-threatening event and in those who survive, there is a risk of long-term neurologic sequelae. A single-center retrospective chart review was performed to look at the utility of central nervous system screening of babies who were diagnosed with moderate or severe hemophilia in the first 7 days of life. Twenty of the twenty-two eligible babies had either a head ultrasound or computerized tomography of the head performed as soon as possible after the diagnosis of hemophilia was confirmed. ICH was found in 3 of the 20 newborns. All patients with ICH had instrument-assisted deliveries with extracranial signs of bleeding/trauma. On the basis of this series we found screening to be safe and effective in recognizing ICH. As a result of this approach, all ICHs were found when they were radiographically small and before the babies had neurologic symptoms.

Imaging of the brain in full-term neonates: does sonography still play a role?

To date the literature comparing the usefulness of US and MR examinations of the neonatal brain suggests that US is not as effective a modality as MR. However, available studies were done on older equipment and published descriptions of the abnormalities found in the term brain are often incomplete. The purpose of this article is to emphasize technical factors that may be useful to optimize US imaging of the term neonatal brain, to provide a description of the sonographic findings in the brain in full-term neonates with hypoxic-ischaemic injury and to provide some data regarding the accuracy of sonography. While MR imaging may reveal abnormalities of the brain more floridly than sonography, we believe that sonography remains an extremely useful modality for evaluation of the full-term neonatal brain and it is probably a more accurate modality in this age group than the current literature suggests. Further prospective studies comparing sonographic and MR imaging findings are required to document the accuracy of sonography better and to help us define the role of this modality better. Such studies may help us select which patients really require MR imaging.

Potential of three-dimensional ultrasound in neonatal and paediatric neurosonography

The aim of this study was to describe the potential of three-dimensional ultrasound (3D US) in paediatric and neonatal neurosonography. The potential applications are illustrated based on our experience in 150 patients using three different 3D US techniques at two different sites. Various disease entities throughout the paediatric age have been evaluated. The potential of 3D US, including 3D US of the cerebral vessels based on colour Doppler data, is discussed based on comparison with conventional 2D US or other imaging (as available), and with regard to the literature. In our experience, 3D US is feasible in neonatal and paediatric neurosonography. It reduces imaging time, improves demonstration of complex anatomy and vasculature, and allows for evaluation of anatomy/pathology in any plane. The 3D US furthermore improves volume assessment (e.g. in hydrocephalus), and comparison with CT, MRI and during follow-up, with a potentially improved standardisation and documentation. The 3D US additionally offers an ideal modality for training and education, as the brain and the neonatal spine can be virtually rescanned at the workstation. Yet, limitations such as areas inaccessible to 2D US, limited resolution and motion artefacts have to be acknowledged. Three-dimensional US has the potential to become a valuable additional imaging tool in paediatric neurosonography.

Mid-trimester fetal subdural hemorrhage: prenatal diagnosis

A routine antenatal ultrasound examination at 20 weeks' gestation revealed a space-occupying lesion in the fetal right cerebral hemisphere. The borders of the mass were indistinct and there was no midline shift. A small collection of echogenic bowel was identified at the right iliac fossa. In an attempt to explain both findings a provisional diagnosis of a fetal blood dyscrasia was made. Fetal cranial magnetic resonance imaging 24 h later confirmed the diagnosis of a subdural hemorrhage. Subsequent fetal blood sampling confirmed severe fetal thrombocytopenia. To our knowledge this is the first report of the antenatal diagnosis of spontaneous mid-trimester fetal subdural hemorrhage.