الفهرس 
Embryology of the brain:Only 14 pages are availabe for public view
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Abstract
Stroke is one of the major complications in children with sickle cell disease (SCD). Ischemic stroke is associated with small asymptomatic subcortical infarcts to large territorial lesions causing major disability. In affected children, Transcranial Doppler sonography is useful for demonstrating involvement of the large cerebral vasculature,
Despite the advances in computed tomography (CT) and magnetic resonance imaging (MRI), sonography is the most commonly used modality for examining the newborn brain. Sonography is still the only modality able to image the brain at the bedside, which can be vital in the case of the critically ill infant.
Moreover Transcranial Doppler (TCD) is widely accepted as the modality of choice for screening intracranial vessels in children with sickle cell disease as it is noninvasive (no need for sedation, contrast material, or radiation), portable, easily repeated, and it provides information about the intracranial vessels that is otherwise unavailable.
TCD was used to identify children at a high risk (two abnormal TCDs with average maximum mean blood flow velocities ≥ 200 cm/second) and chronic transfusions are 90% effective in preventing stroke in these children.
Transcranial Doppler ultrasonography (TCD) screening is employed in children 2–16 years of age; its use in infants is not established, has not been adequately studied. Also determination of whether the TCD values in very young infants with SCA can be used to predict stroke risk later in childhood will require further analysis and long-term follow-up.
In conclusion, abnormal findings on TCD or MRA require a confirmatory test such as CT angiography to reliably identify stenosis, as TCD velocities might not remain high after vessel stenosis, or advances to a critical flow-limiting point.