Vascular segmental location of MRA false-negatives
| Location | Number (n = 19) |
|---|---|
| A1 | 4 (21.1%) |
| Cavernous carotid | 3 (15.8%) |
| M1 | 2 (10.5%) |
| M2 | 4 (21.1%) |
| M4 | 1 (5.3%) |
| P1 | 1 (5.3%) |
| P2 | 1 (5.3%) |
| PcomA | 1 (5.3%) |
| Pericallosal | 2 (10.5%) |
Note:— MRA indicates MR angiography; PcomA, posterior communicating artery.