ABC/2 Formula for Intracerebral Hemorrhage Volume

Estimates intracerebral hemorrhage volume from CT dimensions using bedside ellipsoid-based volumetry.

INSTRUCTIONS

Use this calculator to estimate hemorrhage volume from CT by entering the largest hemorrhage diameter (A), the diameter perpendicular to it (B), the weighted number of involved CT slices, and the slice thickness. For the slice count, slices with at least 75% of the reference hemorrhage area count as 1 slice, slices with about 25% to 75% count as 0.5 slices, and slices with less than 25% count as 0 slices. This weighting approach reflects the classic ABC/2 method described for bedside estimation.

Hemorrhage shape*

Round or ellipsoidround_ellipsoid

Irregular, separated, or multinodularirregular_separated_multinodular

Hemorrhage length*Greatest hemorrhage diameter (A).

Hemorrhage width*Diameter perpendicular to length (B).

Number of CT slices*Use the weighted slice count: slices with ≥75% hemorrhage area count as 1, slices with 25–75% count as 0.5, and slices with <25% count as 0.

slices

CT slice thickness*Slice thickness (C component is weighted slice count × slice thickness).