Unmasking the Imitators: Challenges in Identifying Intracranial Atherosclerosis‐Related Large Vessel Occlusion Mimics During Mechanical Thrombectomy

This manuscript provides a comprehensive review of intracranial atherosclerosis (ICAS)‐related large‐vessel occlusion (ICAS‐LVO) and its mimics, focusing on the challenges in diagnosis and the need for precise diagnostic methodologies, particularly in the context of endovascular therapy. ICAS‐LVO is a significant contributor to acute ischemic stroke, with varying prevalence rates across regions. ICAS‐LVO is characterized by the presence of residual focal fixed stenosis or reocclusion following endovascular treatment or evidence of distal hypoperfusion or watershed infarction on follow‐up imaging. Despite digital subtraction angiography being the gold standard, diagnosing ICAS‐LVO is complicated by similarities with other occlusive conditions, leading to misdiagnosis and inappropriate interventions. The review explores angiographic mimics of ICAS‐LVO, such as intracranial vasospasm, intracranial dissection, partially occlusive thrombus, and rare vasculopathies like Moyamoya disease, reversible cerebral vasoconstriction syndrome, and vasculitis. Each mimic is meticulously examined, providing insights into their distinctive features, diagnostic considerations, and potential interventions. The manuscript emphasizes the importance of early identification of these mimics to guide appropriate interventions and prevent complications. Future perspectives include the incorporation of advanced imaging tools such as integration of artificial intelligence for automated image analysis, and deployment of advanced imaging techniques such as intravascular ultrasound and optical coherence tomography for a more comprehensive radiographical characterization of ICAS‐LVO. Improved diagnostic criteria and ongoing research will play a pivotal role in addressing the challenges of distinguishing ICAS‐LVO from its mimics.