CT Stroke Workup — 3 phases

A standard CT-based stroke workup includes three phases:

• NCCT excludes hemorrhage, early signs hyperdense artery sign, insular ribbon loss, and lentiform nucleus obscuration; quantify damage with ASPECTS (10 = normal).

• CTA identifies Large Vessel Occlusions (may require mechanical thrombectomy) and assesses collaterals — robust collaterals mean slower infarct growth and smaller final infarcts.

• CT Perfusion maps the core (dead) versus penumbra (salvageable). The ischemic core appears as reduced CBF and CBV, while the penumbra shows reduced CBF but preserved CBV with elevated MTT/Tmax.

A significant core-penumbra mismatch - extends the treatment window up to 24 hours (late-window thrombectomy).