Determining the volume of epidural and subdural collections.
Identifying hematomas > 30 cm³, which often require surgical intervention.
Section 2
Formula & Logic
Formula (Ellipsoid Volume)
Volume = (A × B × C) / 2
A = Max diameter (cm)
B = Diameter perpendicular to A (cm)
C = Number of axial slices (thickness in cm)
How to calculate C
Section 3
Pearls/Pitfalls
Shape Assumptions
The ABC/2 method assumes the hematoma is an ellipsoid (football-shaped). For irregular or "grape-like" multinodular hematomas, ABC/2 can overestimate the volume by up to 20%. In these cases, ABC/3 is sometimes proposed, but ABC/2 remains the universal standard for rapid calculation.
Section 4
Literature
Cincinnati Stroke Center
Developed by Kothari and colleagues at the University of Cincinnati as a rapid, bedside-applicable method for quantifying ICH volume on non-contrast CT. It revolutionized ICH prognostication by providing a simple, reproducible measurement that correlates strongly with outcome.
Section 5
Evidence Appraisal
Primary Reference
The ABCs of measuring intracerebral hemorrhage volumes
