Fig 1. A, Diagnostic angiogram of the left internal carotid artery (ICA) reveals good flow across the anterior communicating artery (AcomA) but poor filling of the right MCA territory because of a thrombus demonstrated on an earlier CT angiogram.

B, Successful recanalization of right MCA is seen after administration of 9 mg of tissue plasminogen activator (tPA) into the middle cerebral artery (MCA).

C, Diagnostic angiogram of the left ICA reveals cross-filling through the AcomA into the right MCA. There is probably dilution of contrast in the MCA by nonopacified blood from the ipsilateral posterior communicating artery because good patency of the MCA was demonstrated on the earlier microcatheter injection.