Table 3.
Agreement of Noncontrast Computed Tomography markers across raters with different levels of experience stratified with Cohen’s kappa and the Fleiss kappa.
| NCCT Marker | Rater | Cohen’s Kappa (95% CI) | Rater | Fleiss Kappa (95% CI) |
|---|---|---|---|---|
| Shape Markers | ||||
| IRR Shape | Rad Resident and Neurorad Fellow | 0.88 (0.85–0.92) | Rad Resident, Rad Fellow, and Neurorad Fellow | 0.90 (0.86–0.94) |
| Rad Fellow and Neurorad Fellow | 0.94 (0.92–0.97) | |||
| Satellite Sign | Rad Resident and Neurorad Fellow | 0.94 (0.91–0.96) | Rad Resident, Rad Fellow, and Neurorad Fellow | 0.80 (0.76–0.84) |
| Rad Fellow and Neurorad Fellow | 0.86 (0.78–0.93) | |||
| Island Sign | Rad Resident and Neurorad Fellow | 0.95 (0.92–0.97) | Rad Resident, Rad Fellow, and Neurorad Fellow | 0.86 (0.82–0.91) |
| Rad Fellow and Neurorad Fellow | 0.78 (0.71–0.84) | |||
| Density Markers | ||||
| HET Density | Rad Resident and Neurorad Fellow | 0.85 (0.80–0.89) | Rad Resident, Rad Fellow, and Neurorad Fellow | 0.86 (0.82–0.9) |
| Rad Fellow and Neurorad Fellow | 0.94 (0.91–0.97) | |||
| Swirl Sign | Rad Resident and Neurorad Fellow | 0.96 (0.94–0.98) | Rad Resident, Rad Fellow, and Neurorad Fellow | 0.62 (0.57–0.66) |
| Rad Fellow and Neurorad Fellow | 0.58 (0.52–0.65) | |||
| Black Hole Sign | Rad Resident and Neurorad Fellow | 0.94 (0.91–0.97) | Rad Resident, Rad Fellow, and Neurorad Fellow | 0.79 (0.75–0.84) |
| Rad Fellow and Neurorad Fellow | 0.75 (0.66–0.84) | |||
| Blend Sign | Rad Resident and Neurorad Fellow | 0.70 (0.65–0.81) | Rad Resident, Rad Fellow, and Neurorad Fellow | 0.79 (0.75–0.83) |
| Rad Fellow and Neurorad Fellow | 0.77 (0.67–0.88) | |||
| Fluid Sign | Rad Resident and Neurorad Fellow | 0.96 (0.91–1.00) | Rad Resident, Rad Fellow, and Neurorad Fellow | 0.93 (0.89–0.97) |
| Rad Fellow and Neurorad Fellow | 0.92 (0.86–0.98) | |||
| Hypodensities | Rad Resident and Neurorad Fellow | 0.84 (0.80–0.88) | Rad Resident, Rad Fellow, and Neurorad Fellow | 0.83 (0.79–0.87) |
| Rad Fellow and Neurorad Fellow | 0.83 (0.78–0.87) | |||
Legend: Interrater agreement for nine different Noncontrast Computed Tomography (NCCT) markers with stratified Cohen’s kappa and the Fleiss kappa across one radiology resident, one radiology fellow, and one neuroradiology fellow stratified across one reading. Neuro Fellow, neuroradiology fellow; Rad Fellow, radiology fellow.