Current state and advancements of imaging in acute ischemic stroke: a practical review

Neuroimaging has a pivotal role in the diagnosis, management, and prognostication of acute ischemic stroke (AIS). Developments have improved the ability to identify large vessel occlusions (LVO), delineate salvageable tissue, and guide acute therapeutic interventions. This review aimed to provide an overview of neuroimaging modalities used in AIS evaluation, highlighting their practical applications, recent advancements, and limitations.

We conducted a narrative review of the literature, focusing on non-contrast CT (NCCT), CT angiography (CTA), CT perfusion (CTP), MRI, MR angiography (MRA), digital subtraction angiography (DSA), and transcranial Doppler ultrasonography (TCD). Additionally, we examined emerging trends, such as virtual NCCT, sonothrombolysis and direct-to-angio suite (DTAS) approach. Key aspects, including diagnostic accuracy, clinical utility, and emerging technologies were evaluated.

NCCT remains the cornerstone for initial AIS assessment due to its availability and its ability to assist in rapid decision making. CTA and CTP are integral for detecting LVO and assessing penumbra, respectively, with automated systems enhancing speed and accuracy. MRI helps identify early ischemic changes and rule out stroke mimics. MRA and DSA provide detailed vascular assessments, while TCD offers hemodynamic monitoring and a potential therapeutic role. Limitations include variability in perfusion imaging, MRI availability, and operator dependency in TCD. Emerging techniques like dual-energy CT and AI-driven algorithms enhance diagnostic precision.

Neuroimaging is essential for effective AIS management, with each modality carrying variable strengths and limitations. Continued advancements, standardization and a multi-modal approach are needed to optimize outcomes. Clinical-radiological correlation remains indispensable to reach accurate diagnosis and treatment.