ICH Volume Calculator

Length :

Width :

Slice Thickness:

Number of Slices:

Hemorrhage Shape:

Output Unit:

1. What is the ICH Volume Calculator?

Definition: The ICH Volume Calculator estimates the volume of an intracerebral hemorrhage (ICH) using the ABC/2 formula.

Purpose: It helps clinicians assess the severity of an ICH and guide treatment decisions by estimating the hemorrhage volume, which correlates with prognosis.

2. How Does the Calculator Work?

The calculator uses the ABC/2 formula to compute the ICH volume:

\( \text{ICH Volume} = \frac{\text{Length} \times \text{Width} \times \text{Slice Thickness} \times \text{slices}}{\text{hemorrhage shape factor}} \)

Where the shape factor is 2 for round/ellipsoid hemorrhages and 3 for irregular/separated/multinodular hemorrhages. The interpretation is based on the calculated volume in cm³, with the following ranges:

<30 cm³: Low risk. (Monitor closely; medical management may be sufficient.)
30–60 cm³: Moderate risk. (Consider surgical intervention; consult a neurosurgeon.)
>60 cm³: High risk. (Urgent surgical evaluation recommended; consult a neurosurgeon immediately!)

Inputs:

Length (largest diameter, cm/mm/in)
Width (perpendicular to length, cm/mm/in)
Slice Thickness (height, cm/mm/in)
Number of Slices (from CT scan)
Hemorrhage Shape (Round/Ellipsoid or Irregular/Separated/Multinodular)
Output Unit (mm³/cm³/mL)

Steps:

Input the hemorrhage dimensions (Length, Width, Slice Thickness), number of slices, shape, and select units.
Convert all dimensions to cm for calculation, then compute the ICH volume using the ABC/2 formula.
Convert the result to the selected output unit.
Interpret the result based on volume thresholds (in cm³) and provide a recommended action.

3. Importance of ICH Volume Calculations

The ICH Volume calculation is useful for:

Prognosis Assessment: Larger hemorrhage volumes are associated with worse outcomes.
Treatment Decisions: Helps determine whether surgical intervention is necessary.
Risk Stratification: Classifies patients into low, moderate, or high risk categories for better management.

4. Using the Calculator

Examples:

Length: 20 mm, Width: 20 mm, Slice Thickness: 10 mm, Slices: 5, Shape: Round/Ellipsoid, Output: cm³:
Convert to cm: Length = 2 cm, Width = 2 cm, Slice Thickness = 1 cm.
ICH Volume: \( \frac{2 \times 2 \times 1 \times 5}{2} = 10 \) cm³.
Risk Level: Low risk.
Recommended Action: Monitor closely; medical management may be sufficient.
Length: 2 in, Width: 1.5 in, Slice Thickness: 1 in, Slices: 10, Shape: Irregular/Separated/Multinodular, Output: mm³:
Convert to cm: Length = 5.08 cm, Width = 3.81 cm, Slice Thickness = 2.54 cm.
ICH Volume: \( \frac{5.08 \times 3.81 \times 2.54 \times 10}{3} \approx 163.99 \) cm³.
Output in mm³: \( 163.99 \times 1000 = 163990 \) mm³.
Risk Level: High risk.
Recommended Action: Urgent surgical evaluation recommended; consult a neurosurgeon immediately!

5. Frequently Asked Questions (FAQ)

Q: What is the ABC/2 formula?
A: It’s a method to estimate ICH volume: (Length × Width × Slice Thickness × slices) / shape factor, where the shape factor is 2 or 3 based on hemorrhage shape.

Q: Why does hemorrhage shape matter?
A: Irregular hemorrhages (shape factor 3) are more complex and may have a larger effective volume than round ones (shape factor 2), affecting the calculation.

Q: What does a high ICH volume indicate?
A: A volume >60 cm³ indicates a high risk of poor outcomes, often requiring surgical intervention.