• CEREBROVASCULAR DISEASE

Since 2014, a series of randomised controlled trails (RCTs) have demonstrated the benefit of endovascular thrombectomy (EVT) on functional outcome for the participants who had acute ischaemic stroke (AIS) with occlusion of a proximal intracranial artery in the anterior circulation. The characteristics of the people enrolled in these RCTs have been used to define recommended criteria to select patients for thrombectomy in clinical practice. The initial group of RCTs largely enrolled participants early after AIS (mostly under 6 hours) who had National Institutes of Health stroke scale scores ≥6 (range 0–42 with lower numbers representing milder deficits).1 Neuroimaging to document proximal arterial occlusion and to exclude intracerebral haemorrhage, most commonly CT angiography and non-contrast CT, was used by all of the RCTs. Additional imaging to determine eligibility such as CT or MRI perfusion or MRI diffusion-weighted imaging was not uniformly required. In addition, most of these early enrolling RCTs used the non-contrast CT scan to …