Modified Fisher Scale Wang Jianxin, Department of Neurosurgery, Aviation General Hospital of China Medical University Fisher grade Appearance on CT Scan Possibility of Vasospasm (%) 0 No hemorrhage or intraventricular hemorrhage only 3 or intracerebral parenchymal hemorrhage 1 Basal pool hemorrhage only 14 2 Peripheral or lateral fissure pool hemorrhage only 38 3 Extensive subarachnoid hemorrhage with intracerebral parenchymal hematoma 57 4 Thicker accumulation of blood in basal and peripheral brain pools and lateral fissure pool