Fig. 2. Tendency in brain infarct intensity over time on T1-weighted magnetic resonance imaging. The lesion appears hypointense during the early stage (e.g., 3 h, 3 days) after middle cerebral artery occlusion (A and E). Lesions show a tendency to appear hypointense at the center with peripheral hyperintensity at 8 days (B and F). The hypointense infarct center has a tendency to expand as the peripheral hyperintensity field narrows (C and G). Most infarcts appear hypointense at 35 days (D and H). The images in panels E, G, and H were acquired from the same dog at post-occlusion days 3, 8, and 35, respectively. The image in panel F was acquired from another dog at 8 days and this lesion appears similar to that seen in panel G at 35 days.