Table 1.
Grade 0 | All intracranial vessels show a physiological shape |
Grade 1 | Vasospasm affects the A2, A1, and M2 segments |
Grade 2 | Vasospasm expands to the M1 and terminal segment of the internal carotid artery |
Grade 3 | Severe reduction in the intradural internal carotid artery with filiform A1 and M1 segments, which sometimes appears like a ghost (ghost sign) |