Abstract
Till recently, the mainstay of management of acute ischemic stroke (AIS) has been
intravenous thrombolysis. However, response to treatment and outcomes in the presence
of a large vessel occlusion (LVO) were largely suboptimal. Endovascular thrombectomy
techniques with stentrievers and aspiration catheters have revolutionized stroke treatment
significantly, improving outcomes in this once untreatable disease. The interventional
radiologist must play an active role in the stroke team in streamlining imaging as
well as endovascular management. The focus of this review article is on initial management
and imaging. Initial measures consist of patient resuscitation, basic investigations
and assessment of stroke severity using the National Institutes of Health Stroke Scale
(NIHSS), all of which have therapeutic and prognostic implications to be considered
by the neurointerventionist. Imaging must aim to be swift and efficient. Choice of
a modality must be based on available infrastructure as well as clinical-radiologic
factors such as the time since ictus or posterior circulation involvement. Computed
tomography (CT) is the preferred modality for its speed, whereas magnetic resonance
imaging (MRI) remains the gold standard problem solving technique for detection of
stroke. Exclusion of hemorrhagic stroke and other stroke mimics is the first objective.
Thereafter, imaging is targeted toward assessing the parenchyma and vasculature. Defining
the core and penumbra is the most important goal of parenchymal imaging. The core
may be defined by the presence of early ischemic changes on CT, CT angiographic source
images, or diffusion restriction on MRI. The penumbra is approximated by collateral
status or perfusion methods. The prime directive of vascular imaging, either CT or
magnetic resonance angiography (MRA) is to establish the presence of an LVO. Once
confirmed, the decision for thrombolysis and/or thrombectomy is based on clinical
and imaging criteria, the most ideal being that of a moderately severe stroke with
a small core and LVO on imaging.
Keywords
stroke - mechanical thrombectomy - neurointervention
