Frequencies of superior petrosal vein drainage groups for each cerebellopontine angle (n = 50) and each superior petrosal vein (n = 83)
| Drainage Group | Frequency of Group/Side | Frequency of Group/SPV | ||||
|---|---|---|---|---|---|---|
| Left | Right | Total | Left | Right | Total | |
| Petrosal | 25 | 24 | 49/50 sides (98%) | 31 | 31 | 62/83 (74.7%) |
| Posterior mesencephalic | 22 | 22 | 44/50 sides (88%) | 22 | 23 | 45/83 (54.2%) |
| Anterior pontomesencephalic | 23 | 21 | 44/50 sides (88%) | 27 | 27 | 54/83 (65.1%) |
| Tentorial | 14 | 15 | 29/50 sides (58%) | 14 | 15 | 29/83 (34.9%) |