Table 1:

The original Thrombolysis in Cerebral Infarction perfusion scale2

Grade 0No PerfusionNo antegrade flow beyond the point of occlusion.
Grade 1Penetration with Minimal PerfusionThe contrast material passes beyond the area of obstruction but fails to opacify the entire cerebral bed distal to the obstruction.
Grade 2Partial PerfusionThe contrast material passes beyond the obstruction and opacifies the arterial bed distal to the obstruction. However, the rate of entry of contrast into the vessel distal to the obstruction and/or its rate of clearance from the distal bed are perceptibly slower than its entry into and/or clearance from comparable areas not perfused by the previously occluded vessel.
Grade 2aOnly partial filling (less than two-thirds) of the entire vascular territory is visualized.
Grade 2bComplete filling of all of the expected vascular territory is visualized but the filling is slower than normal.
Grade 3Complete PerfusionAntegrade flow into the bed distal to the obstruction occurs as promptly as into the obstruction and clearance of contrast material from the involved bed is as rapid as from an uninvolved other bed of the same vessel or the opposite cerebral artery.