Radiology of ischemic strokes in children.

Arterial ischemic strokes are a relatively frequent diagnostic occurrence in pediatric neuroradiology. They occur mostly in three main etiologic contexts: congenital heart disease; neonatal distress; infections, focal or general inducing vasculitis, but many cases are considered idiopathic. The positive diagnosis is made by CT; in neonates, however, ultrasound appears as a promising tool. The CT features are basically similar at that age and in adults, although the site of the infarct may result from pathologies more particular to children (e.g. basal ganglia infarction due to arteritis of the carotid siphon and its branches). Infarcts may be multiple and also more frequently hemorrhagic at that age, the hemorrhagic phenomena affecting only the gray matter except in young infants in which the subcortical white matter may be affected also. Anatomical sequels include focal atrophy and asymmetry of the brain. Data regarding the etiology can be gathered from angiography which may show the degree of impairment of the arterial bed, its extent, the collateral blood supply and the morphological type of arterial lesion responsible for the cerebral damage. The most particular picture at that age is that of the often diffuse vasculitis, with its various expressions (segmental narrowing of the lumen, dissecting aneurysm, string-of beads appearance).