Multimodal CT-based imaging biomarkers for mechanical reperfusion in acute ischemic stroke

Mechanical thrombectomy (MT) has emerged as the primary treatment for restoring blood flow in acute ischemic stroke (AIS) patients with large vessel occlusion (LVO). The shift from "time is brain" to "tissue is brain" underscores the significance of multimodal imaging in selecting and triaging AIS patients for endovascular reperfusion therapy. Currently, computed tomography (CT) is the preferred imaging modality for evaluating the infarct core and ischemic penumbra, aiding in the identification of suitable MT candidates. However, the abundance of collected imaging data, containing valuable signs, remains largely unexplored in emergency scenarios and follow-up protocols. A comprehensive investigation of these imaging features, known as "stroke imaging biomarkers," is crucial for accurate predictions regarding AIS pathogenesis, treatment, and prognosis. This exploration can provide valuable support to physicians in their diagnostic and treatment decisions. This review presents an overview of imaging biomarkers associated with ischemic core development, thrombus composition, stroke etiology, reperfusion strategy optimization, and clinical prognosis prediction. Beyond summarizing candidate biomarkers, we critically compare overlapping CT signatures, highlight controversies and failure modes, and synthesize the current level of evidence and barriers to clinical translation. Additionally, the utilization of artificial intelligence in this field, alongside emerging applications and future prospects, is discussed.