Table 3:
Possible causes for disagreement between TOF MRA and DSA in 16 patients
| Location | N (%) | Size (mean, mm) | Overestimation (Size) | Underestimation (Size) |
|---|---|---|---|---|
| ICA | 40 (21.3) | 10.4 | Vessel overlap (9 mm) | Pulsation-induced artifacts (10 mm) |
| AcomA | 65 (34.6) | 5.7 | Vessel overlap (8 mm) | Susceptibility at bone/air interface (2.5 mm) |
| Vessel overlap and small size (2 mm, 3 mm) | ||||
| Partially thrombosed aneurysm (10 mm) | ||||
| Pulsation-induced artifacts (2 mm, 12 mm) | ||||
| ACA | 7 (3.7) | 9.1 | ||
| MCA | 26 (13.8) | 7.1 | Vessel overlap (11 mm) | |
| BA | 23 (12.2) | 7.6 | Pulsation-induced artifacts (10 mm) | Slow flow and small size (2 mm) |
| Saturation effects and small size (3 mm) | ||||
| PcomA | 23 (12.2) | 7.3 | Vessel overlap (10 mm) | |
| Signal void due to slow flow (5 mm) | ||||
| Susceptibility at bone/air interface (3 mm) | ||||
| PICA | 3 (1.7) | 6.7 | ||
| VA | 1 (0.5) | 4.0 | ||
| Total | 188 (100) | 7.5 |
Note:—MRA indicates magnetic resonance angiography; DSA, digital subtraction angiography; ICA, internal carotid artery; AcomA, anterior communicating artery; ACA, anterior cerebral artery; MCA, middle cerebral artery; BA, basilar artery; PcomA, posterior communicating artery; PICA, posterior inferior cerebellar artery; VA, vertebral artery.