| Value | Code Name | Code | Code System | Code Description |
|---|---|---|---|---|
| 0 | Absence of vessels on CTA source images (CTA-SI) | Absence of vessels on CTA source images (CTA-SI) | ||
| 1 | Collateral supply filling <=50% but >0% of the occluded MCA territory | Collateral supply filling <=50% but >0% of the occluded MCA territory | ||
| 2 | Collateral supply filling >50% but <100% of the occluded MCA territory | Collateral supply filling >50% but <100% of the occluded MCA territory | ||
| 3 | 100% collateral supply of the occluded MCA territory | 100% collateral supply of the occluded MCA territory |