A total of 180 segments were studies. Baseline characteristics of the patients are given in Table 4. Before the administration of the anti-TNF treatment, all patients had a faecal calprotectin level greater than 250 μg/g and a SES-CD > 3. For induction of remission, 26 patients (72%) were treated with IFX and 10 (28%) with ADA.

At baseline, ADC values in active segments was significantly lower than in inactive segments (1.54 ± 0.45×10^{− 3} vs. 2.61 ± 0.33×10^{− 3} mm² / s, respectively; p < 0.001). ADC values were also lower in active segments than in inactive segments for the small bowel (1.55 ± 0.37×10^{− 3} vs. 2.72 ± 0.41×10^{– 3} mm²/ s, respectively; p < 0.001) and large bowel (1.34± 0.29×10^{− 3} vs. 2.58± 0.51×10^{– 3} mm²/ s, respectively; p < 0.001). Using a ROC curve, we determined 1.9 × 10^{– 3} mm²/ s as the best threshold for differentiating active (SES-CD ≥ 3) from inactive disease with high sensibility (92%) and specificity (95%).

The administration of the anti-TNF drug induced endoscopic response in 27 patients (75%) and among these a complete disease remission/MH (SES-CD ≤ 2) occurred in 10 patients (28%). 7 patients (19%) showed a stable or slightly lower SES-CD compared to baseline. Only 2 patients (6%) had a SES-CD slightly increased at the end of the study (Figures 1-2).

Using a cut-off point of 4.8 the mean MaRIA was found to have a high accuracy for prediction of endoscopic MH (SES-CD score ≤ 2) with an area under the ROC curve (AUROC) of 0.97 (p = 0.0001). At week 26 the mean MaRIA score was <4.8 in 13 patients (36%).

A mean Clermont score of < 5.2 is highly predictive of CD remission defined as SES-CD score £ 2 with an area under the ROC curve (AUROC) of 0.99 (p = 0.0001). At week 26 the mean Clermont score was <5.2 in 11 patients (31%).

A Δ mean MaRIA score ≥ 4.5 had a diagnostic accuracy for predicting endoscopic remission/MH with sensitivity of 77% and specificity of 87% (area under the curve 0.9012; 95% CI: 0.809-0.99) (Figure 3).

At week 26 the mean MaRIA score decreased of at least 4.5 points in 14 patients (39%) while increased in 4 patients (11%). In the remaining 18 patients (50%) the overall MaRIA score decreased by less than 4 points compared to baseline. 

A Δ mean Clermont score ≥ 4 had an optimal diagnostic accuracy for predicting endoscopic remission/MH with sensitivity of 85% and specificity of 97% (area under the curve 0,9367; 95% CI: 0.86-0.99)(Figure 4).

At week 26 the mean Clermont score decreased of at least 4 points in 15 patients (42%) while increased in 2 patients (5%). In the remaining 19 patients (53%) the mean Clermont score decreased by less than 4 points compared to baseline. 

The mean Clermont score was highly correlated with the mean MaRIA (rho = 0.99).A mean Clermont score of < 5.2 is highly predictive of CD remission defined as SES £ 2 with an area under the ROC curve (AUROC) of 0.99 (p = 0.0001).

The correlation between SES-CD, mean Clermont score and mean MaRIA was statistical significant both and at week 26 (p < 0.001). A significant correlation of the Δ SES-CD was observed with Δ MaRIA (p < 0.001), Δ Clermont score (p < 0.001) and Δ faecal calprotectin (p < 0.001).We observed high interobserver agreement for the mean MaRIA score and the mean Clermont score both at baseline and at week 26 (MaRIA: κ = 0.94, s.e. = 0.86; κ = 0.94, s.e. = 0.91, respectively; Clermont: κ = 0.95, s.e. = 0.89; κ = 0.95, s.e. = 0.92, respectively).