Fisher grade of cerebral vasospasm risk in subarachnoid hemorrhage^[1]

Group	Appearance of blood on head CT scan
1	No blood detected
2	Diffuse deposition or thin layer with all vertical layers (in interhemispheric fissure, insular cistern, ambient cistern) less than 1 mm thick
3	Localized clot and/or vertical layers 1 mm or more in thickness
4	Intracerebral or intraventricular clot with diffuse or no subarachnoid blood

Fisher_SAH_CT_grading_scale.htm

CT: computed tomography.

Reference:

Fisher CM, Kistler JP, Davis JM. Relation of cerebral vasospasm to subarachnoid hemorrhage visualized by CT scanning. Neurosurgery 1980; 6:1.

Graphic 81122 Version 4.0

Fisher grade of cerebral vasospasm risk in subarachnoid hemorrhage[1]