Table 4.
ACG Grades | Definitions |
---|---|
Grade 0 | No collaterals visible to the ischemic site |
Grade 1 | Slow collaterals to the periphery of the ischemic site, with persistence of some of the defect |
Grade 2 | Rapid collaterals to the periphery of the ischemic site, with persistence of the defect, and only to a portion of the ischemic territory |
Grade 3 | Collaterals with slow but complete angiographic blood flow of the ischemic bed by the late venous phase |
Grade 4 | Complete and rapid collateral blood flow to the vascular bed in the entire ischemic territory by retrograde perfusion |
N/A | Not applicable based on the territory or injections available |
ACG indicates the American Society of Interventional and Therapeutic Neuroradiology collateral grading.