Summary of undergraded arteries (n = 5)
| Enrollment Number | Location | Stenosis on MRA Observers 1/2 (%) | Stenosis on DSA (%) | Estimated Causes |
|---|---|---|---|---|
| 33 | Left MCA, proximal M1 | 30/57 | 60 | Observer error |
| 36 | Left MCA, bifurcation area | 40/39 | 57 | Observer error |
| 3 | Left ICA, petrocavernous segment | 80/0 | 60 | Proximal occlusion with reconstructed distal ICA from ECA collaterals |
| 28 | Right ICA, petrocavernous segment | 40/57 | 51 | Borderline stenosis |
| 40 | Right distal VA segment | 45/58 | 73 | Observer error |
Note:—MCA indicates middle cerebral artery; M1, horizontal segment of MCA; ICA, internal carotid artery; ECA; external carotid artery; VA, vertebral artery; MRA, 3D time-of-flight MR angiography; DSA, digital subtraction angiography.