Fig 1. A 62-year-old man imaged <3 hours after sudden onset of right hemiparesis. From left to right, baseline noncontrast CT (NCCT), CTA source images (CTA-SI), CT perfusion CBV color maps (CT-CBV), and follow-up DWI. Noncontrast CT, by using a window center of 35 HU and a width of 15 HU to visualize optimally the gray-white interface, fails to demonstrate a focal region of parenchymal hypoattenuation, yielding an ASPECTS of 10. CTA source images reveal a focal hypoattenuation at the caudate nucleus consistent with acute infarction, yielding an ASPECTS of 9. CT perfusion CBV map shows relative hypoperfusion in the caudate nucleus as well as at the anterior inferior frontal lobe (M1) and anterior superior frontal lobe (M4), yielding an ASPECTS of 7. Follow-up DWI at 37 hours post-CT imaging confirms acute infarctions in the caudate nucleus, M1, and M4, yielding a final ASPECTS of 7.