Varying definitions of TICI grades in the literature
| Category | Definition |
|---|---|
| Grade 0 | No flow |
| No canalization | |
| Complete occlusion | |
| No recanalization/reperfusion | |
| Grade 1 | Minimal recanalization (<20%) |
| Minimal flow (very slow) without significant flow distal to the occlusion site | |
| Limited or no reperfusion | |
| Distal movement of thrombus without reperfusion | |
| Perfusion past initial occlusion, but limited distal branch | |
| Filling | |
| Grade 2 | Partial recanalization—recanalization of some but not all of the occluded arteries |
| Incomplete recanalization/reperfusion | |
| Near-normal flow, with flow distal to the occlusion but not filling the distal branches normally | |
| Grade 2a | Perfusion of <50% of the MCA distribution |
| Partial filling of the entire vascular territory | |
| Partial perfusion with incomplete distal filling of <50% of expected territory | |
| Partial filling of the entire vascular territory | |
| Grade 2b | Partial perfusion with incomplete distal branch filling of ≥50–99% of the expected territory |
| Complete filling, but the filling is slower than normal | |
| Perfusion of half or greater of the vascular distribution of the occluded artery | |
| Grade 2c | Near-complete perfusion without clearly visible thrombus but with delay in contrast run-off |
| Grade 3 | Full perfusion with filling of all distal branches, including M3, M4 |
| Normal flow | |
| Partial recanalization with >50% reperfusion | |
| Full perfusion with normal filling of distal branches in a normal hemodynamic fashion | |
| Grade 4 | Complete recanalization/reperfusion |