Bowel ultrasonography (BUS) is a noninvasive tool for evaluating bowel activity in Crohn's disease (CD) patients. Aim of our multicenter study was to assess whether BUS helps to monitor intestinal activity improvement/resolution following different biological therapies. Adult CD patients were prospectively enrolled at 16 sites in Italy. Changes in BUS parameters [i.e. bowel wall thickening (BWT), lesion length, echo pattern, blood flow changes and transmural healing (TH: normalization of all BUS parameters)] were analyzed at baseline and after 3, 6 and 12 months of different biological therapies. One hundred eighty-eight out of 201 CD patients were enrolled and analyzed (116 males [62%]; median age 36 years). Fifty-five percent of patients were treated with adalimumab, 16% with infliximab, 13% with vedolizumab and 16% with ustekinumab. TH rates at 12 months were 27.5% with an NNT of 3.6. TH at 12 months after adalimumab was 26.8%, 37% after infliximab, 27.2% after vedolizumab and 20% after ustekinumab. Mean BWT improvement from baseline was statistically significant at 3 and 12 months (P < .0001). Median Harvey-Bradshaw index, C-reactive protein and fecal calprotectin decreased after 12 months from baseline (P < .0001). Logistic regression analysis showed colonic lesion was associated with a higher risk of TH at 3 months and a greater BWT at baseline was associated with a lower risk of TH at 3 months [P = .03 (OR 0.70, 95% CI 0.50-0.97)] and 12 months [P = .01 (OR 0.58, 95% CI 0.38-0.89)]. At 3 months therapy optimization during the study was the only independent factor associated with a higher risk of no ultrasonographic response [P = .02 (OR 3.34, 95% CI 1.18-9.47)] and at 12 months disease duration [P = .02 (OR 3.03, 95% CI 1.15-7.94)]. Data indicate that BUS is useful to monitor biologics-induced bowel activity improvement/resolution in CD.

The unavailability of standardized parameters in bowel ultrasonography (US) commonly used in Crohn’s disease (CD) and the shortage of skilled ultrasonographers are 2 limiting factors in the use of this imaging modality around the world. The aim of this study is to evaluate interobserver agreement among experienced sonographers in the evaluation of bowel US parameters in order to improve standardization in imaging reporting and interpretation. Fifteen patients with an established diagnosis of CD underwent blinded bowel US performed by 6 experienced sonographers. Prior to the evaluation, the sonographers and clinical and radiological IBD experts met to formally define the US parameters. Interobserver agreement was tested with the Quatto method (s). All operators agreed on the presence/absence of CD lesions and distinguished absence of/mild activity or moderate/severe lesions in all patients. S values were moderate for bowel wall thickness (s = 0.48, P = n.s.), bowel wall pattern (s = 0.41, P = n.s.), vascularization (s = 0.52, P = n.s.), and presence of lymphnodes (s = 0.61, P = n.s.). Agreement was substantial for lesion location (s = 0.68, P = n.s.), fistula (s = 0.74, P = n.s.), phlegmon (s = 0.78, P = 0.04), and was almost perfect for abscess (s = 0.95, P = 0.02). Poor agreement was observed for mesenteric adipose tissue alteration, lesion extent, stenosis, and prestenotic dilation. In this study, the majority of the US parameters used in CD showed moderate/substantial agreement. The development of shared US imaging interpretation patterns among sonographers will lead to improved comparability of US results among centers and facilitate the development of multicenter studies and the spread of bowel US training, thereby allowing a wider adoption of this useful technique.

Small intestine contrast ultrasonography (SICUS) has emerged as a valuable tool in the detection of intestinal damage in Crohn's disease (CD). Our aim was to develop a numerical index quantitating small bowel damage as detected by SICUS in patients with an established diagnosis of CD. One hundred and ten patients with ileal or ileocolonic CD were prospectively enrolled and followed up for one year. Disease activity was assessed by CDAI and CRP levels. Study variables included bowel wall thickness, lumen diameter, lesion length and number of lesion site. Fistula, mesenteric adipose tissue alteration, abscess and lymphnodes were also considered. Bowel segments were considered as a hollow cylinder. Standardized variations of variables were combined into a statistical and mathematical model to create an algorithm scoring an index value ranging from 0 to 200. Index was subdivided into a severity scale with 5 classes from the lower (A) to the higher score (E). Median lesion index value was significantly higher (p150 and in patients with CRP>5 mg/l (p=0.003). Patients classified in class E and D at SICUS underwent surgery within one year follow up more frequently than those in class C, B and A (p<0.0001). We propose a new index for assessment of small bowel lesions in CD (SLIC: sonographic lesion index for CD) developed by using SICUS. This index may turn ultrasonography in CD from a descriptive qualitative assessment to a quantitative numerical index suitable for comparison studies.