Objective To explore the feasibility of computed tomography enterography (CTE) in the quantitative evaluation of the activity of Crohn's disease (CD). Methods There were 49 CD patients with whole clinical, enteroscopy, and CTE data to be analyzed retrospectively. The patients were graded as inactive (0–2), mild (3–6), and moderate-severe group (>6) based on simplified endoscopic activity score for Crohn's disease (SES-CD). The differences in bowel wall thickening, mural hyperenhancement in the portal vein period, and the ΔCT values were analyzed among groups using ANOVA (analysis of variance) and q test. Then, the parameters were correlated with SES-CD, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). Results In the 49 patients, 13 ones were inactive, 19 ones were mild, and 17 ones were moderate-severe; the thickness of bowel wall, mural hyperenhancement in the portal vein period, and ΔCT value among groups were all significantly different (P < 0.001 in all). Correlative analysis showed that compared with the SES-CD, the bowel wall thickening (r = 0.564, P < 0.001), mural hyperenhancement in the portal vein period (r = 0.585, P < 0.001), and ΔCT value (r = 0.533, P < 0.001) were moderately correlated. Conclusion The mural hyperenhancement in the portal vein period, bowel wall thickening, and ΔCT value can accurately and quantitatively assess the activity of CD lesions and are potential visual biomarkers of CD lesions.

Background: To investigate the value of histogram analysis of magnetic resonance (MR) diffusion kurtosis imaging (DKI) in the assessment of renal cell carcinoma (RCC) grading before surgery. Methods: A total of 73 RCC patients who had undergone preoperative MR imaging and DKI were classified into either a low-grade group or a high-grade group. Parametric DKI maps of each tumor were obtained using in-house software, and histogram metrics between the two groups were analyzed. Receiver operating characteristic (ROC) curve analysis was used for obtaining the optimum diagnostic thresholds, the area under the ROC curve (AUC), sensitivity, specificity and accuracy of the parameters. Results: Significant differences were observed in 3 metrics of ADC histogram parameters and 8 metrics of DKI histogram parameters (P<0.05). ROC curve analyses showed that K app mean had the highest diagnostic efficacy in differentiating RCC grades. The AUC, sensitivity, and specificity of the K app mean were 0.889, 87.9% and 80%, respectively. Conclusions: DKI histogram parameters can effectively distinguish high-and low-grade RCC. K app mean is the best parameter to distinguish RCC grades.

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Objectives To explore the feasibility of diffusion kurtosis imaging (DKI) for evaluating inflammatory activity in Crohn's disease (CD). Materials and methods In all, 51 CD patients were included, who were performed with consecutive enteroscopy, MR and DKI (b values = 0-2000 mm 2 /s). The lesions of bowel segments were graded as inactive (0-2), mild (3-6), and moderatesevere group (> 6) based on simplified endoscopic activity score for Crohn's disease (SES-CD), The abilities of the parameters of DKI and DWI in grading different activity lesions were compared. Results One hundred and twenty-seven bowel segments including inactive (15), mild (45) and moderate-severe (67) were analyzed. ADC (r = − 0.627, p < 0.001), D app (r = − 0.381, p < 0.001) and K app (r = 0.641, p < 0.001) were correlated with SES-CD. These parameters were significantly different among the three groups (all p < 0.001). ROC analysis found ADC had the highest accuracy (AUC = 0.884, p < 0.001) to differentiate inactive from active group with the threshold at 0.865 × 10 −3 mm 2 /s, which was slightly higher than K app (AUC = 0.867, p < 0.001) with the threshold at 0.645, and was obviously higher than D app (AUC = 0.726, p = 0.005). Similarly, ADC also had the highest accuracy (AUC = 0.846, p < 0.001) to differentiate inactive-mild from moderate-severe group with the threshold at 0.825 × 10 −3 mm 2 /s, and minimally higher than K app (AUC = 0.843, p < 0.001) with the threshold at 0.695, and obviously higher than D app (AUC = 0.690, p < 0.001). Conclusion DKI is feasible and comparable to conventional DWI for the evaluation of inflammatory activity in CD.