FIG 5. Images in a 91-year-old man treated with intravenous tPA at 2.9 hours after stroke onset. MR imaging commenced 5.5 hours after onset.

A, DW image shows an infarct (arrow).

B, Precontrast TOF MR angiogram appears to indicate a diminished left M1 and an occluded left M2 MCA (thick arrow). The ACA (thin arrow) appears occluded.

C, Postcontrast TOF MR angiogram shows the ACA segment is normal (thin arrow), the left M1 is occluded (thick arrow), and the left M2 is diminished.