TCD-based grading methods
| Description | Author (No.) | Acute (<24 hr from Symptom Onset)/Nonacute | Reliability Assessed? | Prognostic Significance of Good Collateral Flow Grade in Acute Stroke |
|---|---|---|---|---|
| Asymmetry of flow in ipsilateral ACA and PCA | Zanette et al77 (56) | Acute | No | NS |
| Asymmetric P2 flow and reduced pulsatility | Reinhard et al76 (30) | Nonacute | No | N/A |
| Reinhard et al75 (111) | ||||
| Asymmetric mean blood velocity in proximal ACA or P2 segment of ACA | Muller and Schimrigk2 (48) | Nonacute | No | N/A |
| Accelerated flow in A1 segment of ACA | Kaps et al74 (23) | Acute | No | NS |
| Flow direction relative to Doppler probe | Hennerici et al86,a | Unclear | No | NS |
| Asymmetric flow velocity and pulsatility index | Kim et al35 (51) | Acute | No | NS |
Note:—NS indicates not stated; N/A, not applicable.
↵a Number not stated.