Cognard classification of DAVFs13
| Type | Venous Drainage | Flow Pattern in Sinus | CVD |
|---|---|---|---|
| “Benign” | |||
| I | Dural sinus | Antegrade | No |
| IIa | Dural sinus | Retrograde | No |
| “Aggressive” | |||
| IIb | Dural sinus | Antegrade | Yes |
| IIa+b | Dural sinus | Retrograde | Yes |
| III | Cortical vein | Yes | |
| IV | Cortical vein | Yes + venous ectasia | |
| V | Cortical vein with spinal perimedullary drainage | Yes |