Table 4.
Comparison of observers with reference standard
| MRI Features | Observer 1 | Observer 2 | Observer 3 | ||||
|---|---|---|---|---|---|---|---|
| Median (IQR) | p value | Median (IQR) | p value | Median (IQR) | p value | ||
| Wall thickness (mm) | Normal | 6.0 [4.0–8.0] | 0.000 | 8.0 [7.0–12.0] | 0.023 | 4.0 [3.0–6.8] | 0.000 |
| Proctitis | 9.0 [7.0–10.5] | 11.0 [9.8–12.0] | 10.0 [7.0–12.3] | ||||
| Mesorectal lymph nodes (mm) | Normal | 3.0 [2.0–4.8] | 0.001 | 4.0 [0.0–5.8] | 0.005 | 3.0 [0.5–5.0] | 0.000 |
| Proctitis | 5.0 [4.0–7.0] | 6.0 [4.8–7.3] | 6.0 [4.0–8.0] | ||||
| Obturator lymph nodes (mm) | Normal | 5.0 [4.0–7.0] | 0.647 | 5.0 [0.0–6.0] | 0.535 | 4.0 [3.0–5.0] | 0.905 |
| Proctitis | 6.0 [2.3–7.0] | 5.0 [2.3–6.0] | 4.0 [3.0–5.3] | ||||
| Iliac lymph nodes (mm) | Normal | 5.0 [0.0–7.0] | 0.375 | 5.0 [4.0–7.0] | 0.855 | 0.0 [0.0–4.0] | 0.403 |
| Proctitis | 6.0 [4.0–7.0] | 6.0 [0.0–7.0] | 0.0 [0.0–4.3] | ||||
| Inguinal lymph nodes (mm) | Normal | 8.0 [7.0–9.8] | 0.442 | 8.0 [7.0–9.8] | 0.427 | 8.0 [6.0–10.0] | 0.575 |
| Proctitis | 7.0 [6.0–10.0] | 7.0 [6.0–9.0] | 7.0 [6.0–10.0] | ||||
| MRI Features | Observer 1 | Observer 2 | Observer 3 | |||
|---|---|---|---|---|---|---|
| Exp(B) (95% CI) | p value | Exp(B) (95% CI) | p value | Exp(B) (95% CI) | p value | |
| % of circumference involved | 14.18 (3.60–55.87) | 0.000 | 12.65 (2.60–61.65) | 0.002 | 9.90 (2.96–31.09) | 0.000 |
| Mural T2 signal | 4.34 (1.58–11.91) | 0.004 | 3.16 (1.07–9.37) | 0.038 | 3.90 (1.07–16.30) | 0.062 |
| Perimural T2 signal | 20.43 (4.13–100.99) | 0.000 | 4.79 (1.72–13.34) | 0.003 | 20.25 (4.95–85.76) | 0.000 |
| T1 enhancement | 3.10 (1.15–8.18) | 0.025 | 2.16 (1.30–6.10) | 0.145 | 2.69 (1.01–7.17) | 0.049 |
| T1 enhancement pattern | 2.48 (1.05–6.46) | 0.064 | 6.28 (2.00–19.71) | 0.002 | 2.89 (1.11–7.57) | 0.030 |
| Perimural enhancement | 11.70 (3.27–41.85) | 0.000 | 9.06 (2.81–29.22) | 0.000 | 17.76 (4.35–74.07) | 0.000 |
| Mural fat | 6.67 (1.28–34.92) | 0.025 | 2.23 (0.71–7.06) | 0.172 | 16.41 (1.91–140.75) | 0.011 |
| Ulcers | 0.47 (0.11–2.02) | 0.307 | 1.11 (0.34–3.60) | 0.868 | 9.30 (1.04–83.13) | 0.046 |
| Supralevatoric fistula | 1.25 (0.44–3.56) | 0.673 | 1.60 (0.46–5.52) | 0.460 | 1.93 (0.57–6.51) | 0.291 |
| Supralevatoric abscess | 5.64 (0.59–53.93) | 0.133 | 3.11 (0.82–11.86) | 0.096 | 5.64 (0.60–53.93) | 0.133 |
| Creeping fat | a | 7.09 (1.71–29.35) | 0.007 | 16.41 (1.91–140.75) | 0.011 | |
| Comb sign | 7.00 (1.91–25.67) | 0.003 | 5.96 (1.48–23.97) | 0.012 | 13.18 (3.18–54.57) | 0.000 |
aNot calculated because of the presence of a zero in the crosstab