Table 13.

Grading of coronary flow (according to [45])

Grade	Definition
0 : no perfusion	- no antegrade flow beyond the point of occlusion
1 : penetration with minimal perfusion	- the contrast material passes beyond the area of obstruction, but "hangs up" and fails to opacify the entire coronary bed distal to the obstruction for duration of the cine run
2 : partial perfusion	-the contrast material passes across the obstruction and opacifies the coronary bed distal to the obstruction; the rate of entry of contrast material into the vessel distal to the obstruction or its rate of clearance from the distal bed (or both) are perceptibly slower than its entry into or clearance from comparable areas not perfused by the previously occluded vessel, e.g., the opposite coronary artery or the coronary bed proximal to the obstruction.
3 : complete perfusion	- antegrade flow into the bed distal to the obstruction occurs as promptly as antegrade flow into the bed proximal to the obstruction, and clearance of contrast material from the involved bed is as rapid as clearance from an uninvolved bed in the same vessel or the opposite artery