ASL and susceptibility-weighted imaging contribution to the management of acute ischaemic stroke

ABSTRACT: Magnetic resonance imaging (MRI) plays a central role in the early diagnosis of cerebral vascular events. Today, MRI is used not only for the detection of acute ischaemic lesions, but also to fine tune the diagnosis and improve patient selection for early therapeutic decision-making. In this perspective, new tools such as arterial spin labelling (ASL) and susceptibility-weighted imaging (SWI) sequences have been developed. These MRI sequences enable noninvasive assessment of brain damage, providing important diagnostic and prognostic information: evaluation of cerebral parenchymal perfusion; detection and aetiological assessment of thrombi; ruling out differential diagnoses. After a brief recall of the fundamental basis of these sequences, this article proposes an update on their current contribution to the early management of stroke victims. TEACHING POINTS: • These noninvasive sequences provide essential information for early management of acute stroke. • They can detect zones of parenchymal hypoperfusion. • Susceptibility-weighted sequences provide information on thrombus localisation and composition. • ASL can identify certain aetiologies of stroke mimics. • Post-therapeutic ASL perfusion status predicts outcome.