Table 2:

Interobserver variability of manual SAH volume measurement and comparison of the manual and automatic methods

ICC Volumea (95% CI)Bland-Altman Volume Limits of Agreement (mL)ICC Densitya (95% CI)Bland-Altman Density Limits of Agreement (HU)Dice Coefficient (Mean and Range)No.b
Automatic interobserver0.98 (0.96–0.99)−12.90–12.130.80 (0.62–0.90)−7.58–9.180.55 (0.00–0.83)30
Manual interobserver0.97 (0.77–0.99)−18.68–6.240.98 (0.89–0.99)c−1.52–3.44c0.64 (0.00–0.86)30
  • a Case 3 intraclass correlation coefficients using an absolute agreement definition.

  • b Number of NCCT scans included in the calculation.

  • c Number of NCCT scans included for calculation = 29.