Table 3.
Multirater Kappa and intraclass correlation coefficient values between the observer pairs
| MRI features | 1 vs. 2 | 2 vs. 3 | 1 vs. 3 |
|---|---|---|---|
| Wall thickness | 0.70 (0.54–0.81) | 0.58 (0.38–0.73) | 0.69 (0.53–0.81) |
| Mesorectal lymph nodes | 0.83 (0.72–0.89) | 0.78 (0.66–0.87) | 0.83 (0.72–0.89) |
| Obturator lymph nodes | 0.31 (0.06–0.53) | 0.26 (0.00–0.48) | 0.27 (0.01–0.49) |
| Iliac lymph nodes | 0.38 (0.14–0.58) | 0.23 (−0.03–0.46) | 0.24 (−0.01–0.47) |
| Inguinal lymph nodes | 0.65 (0.48–0.78) | 0.38 (0.14–0.58) | 0.43 (0.20–0.62) |
| % of circumference involved | 0.16 (0.03–0.29) | 0.17 (0.06–0.27) | 0.47 (0.27–0.67) |
| Mural T2 signal | 26% (15/58)a | 43% (25/58)a | 41% (24/58)a |
| Perimural T2 signal | 0.50 (0.34–0.67) | 0.57 (0.41–0.73) | 0.71 (0.58–0.85) |
| T1 enhancement | 0.13 (0.03–0.24) | 0.14 (0.01–0.27) | 0.39 (0.22–0.56) |
| T1 enhancement pattern | 0.13 (0.02–0.25) | 0.25 (0.12–0.38) | 0.43 (0.25–0.61) |
| Perimural enhancement | 0.46 (0.29–0.64) | 0.34 (0.17–0.50) | 0.59 (0.42–0.76) |
| Mural fat | 0.67 (0.44–0.90) | 0.57 (0.34–0.81) | 0.64 (0.37–0.90) |
| Ulcers | 64% (37/58)a | 0.13 (0–0.39) | 0.25 (0–0.57) |
| Supralevatoric fistula | 0.48 (0.24–0.72) | 0.57 (0.31–0.82) | 0.59 (0.39–0.79) |
| Supralevatoric abscess | 0.53 (0.21–0.86) | 0.53 (0.24–0.82) | 1 |
| Creeping fat | 0.48 (0.18–0.77) | 0.69 (0.46–0.92) | 0.76 (0.53–0.98) |
| Comb sign | 0.18 (0.01–0.34) | 0.20 (0.03–0.36) | 0.55 (0.32–0.78) |
aProportion of agreement calculated instead of kappa, because observed concordance is smaller than mean-chance concordance