CT-based collateral scoring methods
| Modality | Description | Grading | Author (No.) | Acute (<24 hr from Symptom Onset)/Non-Acute | Reliability Assessed? | Prognostic Significance of Good Collateral Flow Grade in Acute Stroke |
|---|---|---|---|---|---|---|
| Axial CTA-SI | Extent of perilesional vessel filling | None, moderate, good, excellent | Liebeskind64 (36) | Acute | Yes, ICC = 0.81 | NS |
| CTA-SI | Comparison of Sylvian collaterals with contralateral hemisphere | Absent, less, equal to, greater than contralateral hemisphere, exuberant | Rosenthal et al65 (44) | Acute | No | Beneficial65–67 |
| Maas et al66 (135) | ||||||
| Lima et al67 (196) | ||||||
| CTA-SI and MPR | Extent of perilesional enhancement | Good, poor | Schramm et al68 (20) | Acute | Yes, κ = 0.494 | Beneficial68,69 |
| Tan et al69 (113) | ||||||
| CTA-SI and reconstructions | MCA filling in Sylvian fissure | Good, moderate, absent | Wildermuth et al70 (40) | Acute | Yes | Beneficial70,71 |
| Knauth et al71 (21) | 88% agreement between 2 raters71 | |||||
| CTA MIP | Extent of filling in territory of occluded vessel | 0–3 | Tan et al69 (113) | Acute | Yes | Beneficial69.72,73 |
| Tan et al72 (85) | κ = 0.66969, ICC 0.8772 | |||||
| Soares et al73 (22) | ||||||
| CTA, MIP, CTP | Retrograde filling of MCA | Good, moderate, poor | Miteff et al5 (92) | Acute | Yes | Beneficial |
| κ = 0.93 | ||||||
| (TCTP) | Extent of perfusion deficit on TCTP | Severe, moderate | Lee et al34 | Acute | No | NS |
Note:—NS indicates not stated; ICC, intraclass correlation coefficient; CTA-SI, CT angiography source images; MPR, multiplanar reconstruction; MIP, maximum intensity projection; TPCT, triphasic CTP.