Summary of imaging findingsa
| Morphology | Fenestration (n = 59) | Septation (n = 21) |
|---|---|---|
| Location | ||
| Inferior third (No.) (%) | 53 (89.8%) | 14 (66.7%) |
| Middle third (No.) (%) | 4 (6.8%) | 5 (23.8%) |
| Superior third (No.) (%) | 2 (3.4%) | 2 (9.5%) |
| Associated findings | ||
| Calcification (No.) (%) | 3 (5.1%) | 13 (61.9%) |
| Cerebral infarction (No.) (%) | 14 (23.7%) | 2 (9.5%) |
| Parenchymal hemorrhage (No.) (%) | 5 (8.5%) | 2 (9.5%) |
| Coincident vascular abnormalities | ||
| Vertebral dissection (No.) (%) | 2 (3.4%) | 1 (4.8%) |
| Carotid dissection (No.) (%) | 2 (3.4%) | 1 (4.8%) |
| Carotid web (No.) (%) | 1 (1.7%) | 0 |
| Fibromuscular dysplasia (No.) (%) | 5 (8.5%) | 0 |
↵a A total of 80 cases with basilar artery intraluminal findings were identified. The location and distribution along the course of the basilar artery were similar for fenestrations and septations. Rarely, arterial dissections were found in the extracranial segments of vertebral artery or internal carotid artery. No intracranial dissections were identified in any of the cases.