Advances in paediatric CNS ultrasound

Advanced paediatric ultrasound of the central nervous system (CNS) requires 7 MHz sector and linear transducers, equipment which is highly sensitive to flow velocity (Power Doppler) and additional transcranial axial, coronal and sagittal imaging. New diagnostic possibilities include recognition of subarachnoid hemorrhage (imaging of cisterns and/or CSF-flow); differentiation between subarachnoid and subdural fluid collections (colour flow imaging of traversing veins); additional criteria suggestive of spinal cord tethering (spinal cord pulsations); and grey-white matter differentiation in newborn infants. A meticulous examination technique is mandatory when investigating suspected brain death, sinus venous thrombosis, diffuse early ischemia or viral (herpes) encephalitis. Anatomical areas such as the cerebral aqueduct, tentorium, Foramina of Luschka or circle of Willis which are not usually regarded as accessible to cerebral echography can be visualized by advanced transcranial imaging technique. Indications for transcranial scanning; shortcomings of cerebral ultrasound; measures to overcome limitations; and requirements for present and future ultrasound equipment are given and discussed in tables.