BNI scale measures increasing SAH thickness on a quantitative scale and is used to predict the likelihood to develop symptomatic vasospasm. The axial head CT for the slice demonstrating the thickest-appearing subarachnoid blood in any subarachnoid space is examined. The thickness of the subarachnoid blood is measured across the cistern or fissure (ie, perpendicular to the direction of the cistern or fissure on axial cut) in the thickest-appearing region. The scale is based on 5-mm increments of SAH thickness.
BNI scale measures increasing SAH thickness on a quantitative scale and is used to predict the likelihood to develop symptomatic vasospasm. The axial head CT for the slice demonstrating the thickest-appearing subarachnoid blood in any subarachnoid space is examined. The thickness of the subarachnoid blood is measured across the cistern or fissure (ie, perpendicular to the direction of the cistern or fissure on axial cut) in the thickest-appearing region. The scale is based on 5-mm increments of SAH thickness.