Role of Advanced Magnetic Resonance Imaging in Assessment of Pediatric Cerebral Stroke

Overview

Stroke can be ischemic, hemorrhagic, or both. Early recognition and treatment of pediatric stroke are critical in optimizing long-term functional outcomes, reducing morbidity and mortality, and preventing recurrent stroke. Neuroimaging plays a vital role in achieving this goal. Neuroimaging is usually the first step in diagnosis, helping discriminate between ischemic/hemorrhagic strokes and also in the identification of underlying potential causes. Multiparametric magnetic resonance imaging (MRI) plays a crucial role in assessing pediatric cerebral stroke including diffusion-weighted imaging (DWI), susceptibility weighted imaging (SWI) and magnetic resonance angiography (MRA).

Stroke is a neurological injury caused by the occlusion or rupture of cerebral blood vessels. Stroke can be ischemic, hemorrhagic, or both. Ischemic stroke is more frequently caused by arterial occlusion, but it may also be caused by venous occlusion of cerebral veins or sinuses. Hemorrhagic stroke is the result of bleeding from a ruptured cerebral artery or from bleeding into the site of an acute ischemic stroke. Stroke is relatively rare in children but can lead to significant morbidity and mortality. Understanding that children with strokes present differently than adults and often present with unique risk factors will optimize outcomes in children. Early recognition and treatment of pediatric stroke are critical in optimizing long-term functional outcomes, reducing morbidity and mortality, and preventing recurrent stroke. Neuroimaging plays a vital role in achieving this goal. Neuroimaging is usually the first step in diagnosis, helping discriminate between ischemic/hemorrhagic strokes and also in the identification of underlying potential causes MRI is a more sensitive test for early detection of an infarction. Magnetic resonance arteriography (MRA) and magnetic resonance venography (MRV) should also be carried out to confirm vessel patency and define the vascular anatomy. MRA will yield further information about blood flow, and MRV will more reliably identify cerebral venous sinus thrombosis. MRI has a high sensitivity and specificity in the first hours after symptom onset with the potential to both characterize the ischemic pathology and to differentiate ischemic from hemorrhagic lesions at least as accurately as computed tomography (CT). Most common imaging protocol used for acute ischemic stroke is an emergent/urgent stroke protocol MRI with MRA. This usually takes approximately 13 min for the MRI sequences and 19 min with MRA.