Relevance of sonographic parameters for inflammatory bowel disease in children

PURPOSE

Intestinal ultrasound (IUS) is widely used as the first exam in patients with suspected inflammatory bowel disease (IBD). This study investigated the accuracy of several IUS parameters, including increased bowel wall thickening (BWT), in detecting IBD in a paediatric population.

METHODS

The study included an unselected series of 113 patients aged 2-18 years (mean age 10.8 years, 65 male), referred for recurrent abdominal pain or altered bowel habits, without known organic diseases, to perform an IUS as first investigation of a diagnostic workup. Patients with full systematic IUS examination, clinical and biochemical exams, and ileocolonoscopy or an uneventful follow-up at least one year follow up were eligible.

RESULTS

23 IBD patients (20.4%; 8 ulcerative colitis, 12 Crohn's disease and 3 indeterminate colitis) were diagnosed. We found that increased BWT > 3 mm (OR 5.4), altered IUS bowel pattern (IUS-BP, OR 9.8) and mesenteric hypertrophy (MH, OR 5.2) accurately identified IBD at the multivariate analysis. IUS-BP, MH and BWT > 3 mm had a sensitivity of 78.3%, 65.2% and 69.6% and a specificity of 93.3%, 92.2% and 96.7%, respectively. The combination of these three alterations increased the specificity up to 100%, whilst decreased sensitivity to 56.5%.

CONCLUSION

Among several US parameters suggestive of IBD, the increased BWT, MH and altered echopattern are independent predictors of IBD. The ultrasonographic diagnosis of IBD could be more accurate if relied on combination of different sonographic parameters, than on the sole BWT evaluation.

Clinical outcome is distinct between radiological stricture and endoscopic stricture in ileal Crohn's disease

OBJECTIVES

Differences in clinical adverse outcomes (CAO) based on different intestinal stricturing definitions in Crohn's disease (CD) are poorly documented. This study aims to compare CAO between radiological strictures (RS) and endoscopic strictures (ES) in ileal CD and explore the significance of upstream dilatation in RS.

METHODS

This retrospective double-center study included 199 patients (derivation cohort, n = 157; validation cohort, n = 42) with bowel strictures who simultaneously underwent endoscopic and radiologic examinations. RS was defined as a luminal narrowing with wall thickening relative to the normal gut on cross-sectional imaging (group 1 (G1)), which further divided into G1a (without upstream dilatation) and G1b (with upstream dilatation). ES was defined as an endoscopic non-passable stricture (group 2 (G2)). Strictures met the definitions of RS (with or without upstream dilatation) and ES were categorized as group 3 (G3). CAO referred to stricture-related surgery or penetrating disease.

RESULTS

In the derivation cohort, G1b (93.3%) had the highest CAO occurrence rate, followed by G3 (32.6%), G1a (3.2%), and G2 (0%) (p < 0.0001); the same order was found in the validation cohort. The CAO-free survival time was significantly different among the four groups (p < 0.0001). Upstream dilatation (hazard ratio, 1.126) was a risk factor for predicting CAO in RS. Furthermore, when upstream dilatation was added to diagnose RS, 17.6% of high-risk strictures were neglected.

CONCLUSIONS

CAO differs significantly between RS and ES, and clinicians should pay more attention to strictures in G1b and G3. Upstream dilatation has an important impact on the clinical outcome of RS but may not be an essential factor for RS diagnosis.

CLINICAL RELEVANCE STATEMENT

This study explored the definition of intestinal stricture with the greatest significance for the clinical diagnosis and prognosis of patients with CD, and consequently provided effective auxiliary information for clinicians to formulate strategies for the treatment of CD intestinal strictures.

KEY POINTS

• The retrospective double-center study showed that clinical adverse outcome is different between radiological strictures and endoscopic strictures in CD. • Upstream dilatation has an important impact on the clinical outcome of radiological strictures but may not be an essential factor for diagnosis of radiological strictures. • Radiological stricture with upstream dilatation and simultaneous radiological and endoscopic stricture were at increased risk for clinical adverse outcomes; thus, closer monitoring should be considered.

Preoperative Magnetic Resonance Enterography to Predict Pathological Specimen Length in Crohn's Disease

BACKGROUND

The European Crohn's and Colitis Organization guidelines have highlighted the importance of the preoperative evaluation of the affected segment length in patients with ileocolic Crohn's disease to determine the best surgical approach.

OBJECTIVE

This study aimed to evaluate the accuracy of preoperative magnetic resonance enterography in assessing the length of the affected segment in patients with ileocolic Crohn's disease.

DESIGN

This observational study was conducted with a prospectively maintained database and retrospective analysis.

SETTINGS

This study was conducted in a tertiary center.

PATIENTS

This study included consecutive patients undergoing ileocolic resection for Crohn's disease between August 2014 and June 2020. All patients underwent a preoperative magnetic resonance enterography.

MAIN OUTCOME MEASURES

The correlation between the length measured on magnetic resonance enterography and pathological examination was evaluated.

RESULTS

A total of 96 patients were included. The median time between magnetic resonance enterography and surgery was 65.5 (3-331) days. The length of the affected segment on magnetic resonance enterography was correlated with the length assessed on pathological evaluation ( R = 0.48, p < 0.001). No correlation was found between the 2 measurements when imaging was performed >6 months before surgery ( R = 0.14, p = 0.62). The presence of an abscess underestimated the length affected by Crohn's disease on imaging compared to pathology, whereas the presence of a fistula was associated with magnetic resonance enterography overestimation of the length of the affected segment.

LIMITATIONS

Limitations included single-center study and retrospective analysis.

CONCLUSION

In Crohn's disease, preoperative magnetic resonance enterography is a highly reliable tool for predicting the length of the affected segment compared to pathology examination in the absence of an abscess or fistula. See Video Abstract at http://links.lww.com/DCR/C26 .

ENTEROGRAFA POR RESONANCIA MAGNTICA PREOPERATORIA PARA PREDECIR LA LONGITUD DE MUESTRAS PATOLGICAS EN LA ENFERMEDAD DE CROHN

ANTECEDENTES:Las guías de la Organización Europea de Crohn y Colitis han resaltado la importancia de la evaluación preoperatoria de la longitud del segmento afectado para determinar el mejor abordaje quirúrgico.OBJETIVO:Evaluamos la precisión de la enterografía por resonancia magnética preoperatoria para evaluar la longitud del segmento afectado en pacientes con enfermedad de Crohn ileocólica.DISEÑO:Realizamos un estudio observacional con una base de datos mantenida prospectivamente y un análisis retrospectivo.CONFIGURACIÓN:Este estudio se realizó en un centro terciario.PACIENTES:Se incluyeron pacientes consecutivos sometidos a resección ileocólica por enfermedad de Crohn entre Agosto de 2014 y Junio de 2020. A todos los pacientes se les realizó una enterografía por resonancia magnética preoperatoria.PRINCIPALES MEDIDAS DE RESULTADO:Se evaluó la correlación entre la longitud medida en la enterografía por resonancia magnética y el examen patológico.RESULTADOS:Se incluyeron un total de 96 pacientes. El tiempo mediano entre la enterografía por resonancia magnética y la cirugía fue de 65,5 (3-331) días. La longitud del segmento afectado en la enterografía por resonancia magnética se correlacionó con la longitud evaluada en la evaluación patológica ( R = 0,48, p < 0,001). No hubo correlación entre las 2 mediciones cuando las imágenes se realizaron más de 6 meses antes de la cirugía ( R = 0,14, p = 0,62). La presencia de un absceso subestimó la longitud afectada por la enfermedad de Crohn en las imágenes en comparación con la patología, mientras que la presencia de una fístula se asoció con una sobrestimación de la longitud del segmento afectado por enterografía por resonancia magnética.LIMITACIONES:Las limitaciones incluyeron un estudio de un solo centro y un análisis retrospectivo.CONCLUSIÓNES:En la enfermedad de Crohn, la enterografía por resonancia magnética preoperatoria es una herramienta altamente confiable para predecir la longitud del segmento afectado en comparación con el examen de patología, en ausencia de absceso o fístula. Consulte el Video Resumen en http://links.lww.com/DCR/C26 . (Traducción-Dr. Yesenia Rojas-Khalil ).

Mesenteric creeping fat index defined by CT enterography is associated with early postoperative recurrence in patients with Crohn's disease

OBJECTIVES

To investigate the value of mesenteric creeping fat index (MCFI) defined by computed-tomography enterography (CTE) in patients with Crohn's Disease (CD) for predicting early postoperative recurrence.

METHODS

A total of 110 patients with CD who underwent CTE and I-stage intestinal resection surgery from December 2013 to December 2018 were enrolled. Two radiologists independently assessed CTE parameters, including MCFI, with scores ranging from 1 to 8; bowel-wall thickening, with a scale of 1 to 3; mural hyperenhancement, mural stratification, submucosal fat deposition, mesenteric fibrofatty proliferation, mesenteric hypervascularity, mesenteric fat stranding, with a scale of 0 to 2; abscess/fistula, enlarged mesenteric lymph node, abdominal and pelvic effusion, with a scale of 0 to 1. Imaging findings associated with early recurrence were assessed using logistic regression analysis.

RESULTS

Within one year follow-up, early postoperative recurrence occurred in 56.4 % (62/110) patients with CD. In univariate analysis, MCFI, bowel-wall thickening, mesenteric hypervascularity, mesenteric fat stranding, abscess/fistula and mesenteric lymphadenopathy were associated with early postoperative recurrence. Among all variables, MCFI (score ≥ 4) contributes the optimal AUC (0.838 [0.758-0.919]), specificity (89.6 %), positive predictive value (90.7 %), accuracy (83.6 %), and risk ratio (OR = 32.42 [10.69-98.33], p < 0.001). In multivariate analysis, only MCFI was an independent predictor of early postoperative recurrence (OR = 25.71 [7.65-86.35], p < 0.001).

CONCLUSION

CTE features are useful in predicting early postoperative recurrence in patients with CD, MCFI may be a valuable tool for clinical monitoring and follow-up.

Sarcopenia assessed by computed tomography or magnetic resonance imaging is associated with the loss of response to biologic therapies in adult patients with Crohn's disease

Sarcopenia occurs in patients with Crohn's disease (CD). However, the association between sarcopenia and loss of response (LOR) to biologic agents remains unclear. This study explored such an association in CD patients. This retrospective study included 94 CD patients who received biologic therapy. The skeletal muscle cross-sectional area at the third lumbar was assessed by computed tomography or magnetic resonance imaging for sarcopenia evaluation. A LOR was defined by fecal calprotectin (FC) < 250 μg/g or >50% reduction from baseline levels or other factors, such as the used agent being replaced by other biologic agents. The association between sarcopenia and LOR was assessed by logistic regression analysis. LOR was observed in 54 patients (57.4%). The prevalence of sarcopenia in the LOR group was higher than that in response group (70.4% vs. 40.0%, p = 0.003). Sarcopenia (odds ratio [OR] = 3.89, 95% confidence interval [CI]: 1.31-11.54), Montreal L1 type (OR = 0.20, 95% CI: 0.06-0.60), perianal lesions (OR = 4.08, 95% CI: 1.31-12.70), and monocytes percentage (OR = 1.27, 95% CI: 1.02-1.57) at baseline were independent associated factors for LOR. Sarcopenia was also associated with LOR in patients who received infliximab (OR = 3.31, 95% CI: 1.11-9.87). Montreal L1 type, perianal lesions, and monocytes percentage (Model 1), and with additional consideration of sarcopenia (Model 2), were developed to predict LOR. Model 2 showed better performance than Model 1 (area under the curve [AUC] 0.82 vs. 0.75). Sarcopenia was associated with the LOR to biological agents or infliximab in adult patients with CD.

Noninvasive Assessment of Postoperative Disease Recurrence in Crohn's Disease: A Multicenter, Prospective Cohort Study on Behalf of the Italian Group for Inflammatory Bowel Disease

BACKGROUND & AIMS

Colonoscopy (CS) is the gold standard to assess postoperative recurrence (POR) in Crohn's disease (CD). However, CS is invasive and may be poorly tolerated by patients. The aim of this study was to prospectively assess the diagnostic accuracy of a noninvasive approach in detecting POR, using the endoscopic Rutgeerts' score (RS) as the reference standard.

METHODS

Consecutive patients with CD who underwent ileo-cecal resection were prospectively enrolled in 3 referral Italian centers. Patients underwent CS and bowel ultrasound within 1 year of surgery. Uni- and multivariable analyses were used to assess the correlation between noninvasive parameters and endoscopic recurrence, defined by a RS ≥2.

RESULTS

Ninety-one patients were enrolled. Sixty patients (66%) experienced endoscopic POR. The multivariable analysis identified bowel wall thickness (BWT) per 1-mm increase (odds ratio [OR], 2.43; 95% confidence interval [CI], 1.21-4.89; P = .012), the presence of mesenteric lymph nodes (OR, 15.63; 95% CI, 1.48-164.54; P = .022), and fecal calprotectin (FC) values ≥50 mcg/g (OR, 8.58; 95% CI, 2.45-29.99; P < .001) as independent predictors for endoscopic recurrence. The presence of lymph nodes or the combination of BWT ≥3 mm and FC values ≥50 mcg/g correctly classified 56% and 75% of patients, with less than 5% of patients falsely classified as having endoscopic recurrence. Conversely, the combination of BWT <3 mm and FC <50 mcg/g correctly classified 74% of patients with only 4.5% of patients falsely classified as not having endoscopic recurrence.

CONCLUSIONS

A noninvasive approach combining bowel ultrasound and FC can be used with confidence for detecting POR in patients with CD without the requirement for CS.

Diffusion-weighted imaging in Crohn's disease

BACKGROUND

Diffusion-weighted MRI (DWI) is routinely used in abdominal imaging. In addition to neoplastic diseases, inflammatory changes can be delineated and diagnosed based on diffusion restriction in DWI. DWI is also increasingly used in the context of MRI of the small and large intestine.

OBJECTIVE

This article focuses on the technical aspects of DWI and its role in the diagnosis of Crohn's disease (CD) as well as in the grading of disease severity and in treatment monitoring.

MATERIALS AND METHODS

Guidelines, basic research papers, and review articles were analyzed.

RESULTS

Diffusion-weighted MRI is a specialized MRI technique that visualizes the diffusion of water molecules in biological tissues. In the context of MRI of the small and large intestine, DWI facilitates the diagnosis of inflammatory bowel disease and assessment of treatment response. DWI enables detection of not only intra- and transmural changes, but also extramural pathologies and complications. However, DWI also has its limitations and challenges.

CONCLUSION

This article provides a comprehensive overview of the use of DWI for diagnostic evaluation of bowel wall changes and extramural complications in the setting of CD. It also summarizes the relevant evidence available in the literature.

Colonic involvement in inflammatory bowel diseases: spotlight on the role of magnetic resonance enterography

The large bowel can be affected by inflammatory bowel diseases, namely ulcerative colitis and Crohn's disease, with the latter occurring either as a unique localization or in conjunction with simultaneous ileal involvement. The differential diagnosis among these conditions is challenging and relies on clinical symptoms, laboratory tests and endoscopy with biopsy. However, as these features can overlap, a conclusive diagnosis is not always achievable, and the underlying cause remains indeterminate. Currently, endoscopy is the reference standard for colonic assessment, although its invasiveness limits its use and repetition within a short timeframe. Magnetic Resonance Enterography is a non-invasive, radiation-free technique that has been extensively and effectively employed in the intestinal evaluation of patients with Crohn's disease in recent years. Although the main goal of this technique is generally focused on evaluating small bowel loops, it can also provide important information about the large bowel if an adequate fulfillment by the oral contrast medium is achieved. The purpose of this work is, therefore, to put emphasis on the potential role of Magnetic Resonance Enterography in assessing the large bowel. In fact, this imaging modality is capable of providing valuable information for comprehensive staging and follow-up of inflammatory bowel diseases within the large bowel, thus complementing the clinical picture and the endoscopic features in the context of a differential diagnosis.

Evaluating the diagnostic accuracy of magnetic resonance imaging in distinguishing strictures in Crohn's disease: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis sought to assess the diagnostic accuracy of magnetic resonance imaging (MRI) in distinguishing fibrotic from inflammatory strictures in Crohn's disease (CD) patients.

METHODS

A rigorous and systematic exploration of five key databases yielded studies that met predefined criteria. Data were extracted for a comprehensive meta-analysis using MetaDiSC and MetaDTA software, providing diagnostic accuracy measures. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool was utilized for evaluating the methodological quality and potential bias within the studies.

RESULTS

The systematic review involved the evaluation of 7437 records, culminating in the inclusion of 22 studies. In detecting fibrotic strictures in CD patients, MRI exhibited a pooled sensitivity of 85.20% (95% CI: 76.10-91.20%) and specificity of 96.00% (95% CI: 87.80-98.70%). For differentiating fibrotic strictures from inflammatory stenosis, the sensitivity was 81.5% (95% CI: 70.2-89.20%), and the specificity was 97.2% (95% CI: 90.0-99.3%). In terms of assessing the severity of strictures, sensitivity stood at 90.4% (95% CI: 78.1-96.1%) and specificity at 89.4% (95% CI: 57.4-98.2%). The consistency of the diagnostic accuracy was observed across different geographical locations and the various reference tests applied in the studies.

CONCLUSIONS

The results of this meta-analysis underscore the robust diagnostic accuracy of MRI in detecting fibrotic strictures, distinguishing between fibrotic and inflammatory strictures, and evaluating stricture severity in CD patients. These findings support the integration of MRI into standard diagnostic protocols for patients with CD. Further large-scale, multicenter trials are warranted to confirm these results and to identify any potential limitations associated with the application of MRI in this clinical setting.

Distribution of small bowel involvement and its association with clinical outcomes in patients with Crohn's disease

We aimed to evaluate the distribution of small-bowel involvement in Crohn's disease (CD) and its association with clinical outcomes. This study included CD patients who underwent computed tomography (CT) at initial diagnosis from June 2006 to April 2021. Two abdominal radiologists reviewed the CT images, and independently rated the presence of "bowel wall thickening," "stricture," and "fistula or abscess" in the small bowel segments of jejunum, distal jejunum/proximal ileum, distal ileum, and terminal ileum, respectively. Based on findings of the image review, each patient's "disease-extent imaging score" and "behavior-weighted imaging score" (a higher score indicative of more structuring or penetrating disease) were calculated. Major clinical outcomes (emergency department [ED] visit, operation, and use of corticosteroids or biologics) were compared according to the 2 scores and L4 involvement by the Montreal classification. The proportions of involvement in the jejunum, distal jejunum/proximal ileum, distal ileum, and terminal ileum were 2.0%, 30.3%, 82.2%, and 71.7%, respectively, identifying 30.3% of patients as having L4 disease and 69.7% of patients as having involvement of multiple segments. Clinical outcomes were not significantly associated with the disease-extent imaging score or L4 involvement. However, significant differences were noted for the ED visits and the use of biologics, according to the behavior-weighted imaging score. Moreover, in multivariable analysis, disease behavior was the only factor associated with all clinical outcomes (ED visit, hazard ratio [HR] 2.127 [1.356-3.337], P = .001; operation, HR 8.216 [2.629-25.683], P < .001; use of corticosteroid, HR 1.816 [1.249-2.642], P = .002; and use of biologics, HR 2.352 [1.492-3.708], P < .001). Initial disease behavior seems to be a more critical factor for clinical outcomes of CD than the extent or distribution of small-bowel involvement on CT.

Typical MR features and interpretation of perianal fistulas in patients with Crohn's disease

Perianal fistulas in Crohn's disease (CD) are a poor prognostic phenotype requiring a combination of medical and surgical management. Perianal fistulas in CD are characterized by more complex and multi-branched fistulas, association with skin tags, and frequent presence of proctitis. A comprehensive approach with clinical examination, endoscopic and MR assessment is required, and in particular, MR interpretation provides detailed information on the type of fistula with its internal component and activity, secondary tracts and extension, internal, external openings, associated abscess, and presence of proctitis. Structured reporting of these items would be recommended for further discussion and management planning both at initial diagnosis and for disease monitoring during treatment follow-up. Management strategy would be individualized for each patient, and control of luminal disease activity could be an important determinant in the selection of treatment options. In this review, we provide an overview of the MRI evaluation of perianal fistulas in CD with a proposed structured MR report.

Serial Changes in Intestinal Stenotic Stiffness in Patients with Crohn's Disease Treated with Biologics: A Pilot Study Using Ultrasound Shear Wave Elastography

BACKGROUND/AIMS

Intestinal strictures represent an important serious complication of Crohn's disease. Shear wave elastography is a promising noninvasive ultrasound technique for assessing tissue stiffness. This study aimed to evaluate stiffness in the areas of intestinal stricture in patients with Crohn's disease using shear wave elastography and the changes in stiffness after biologics.

MATERIALS AND METHODS

We enrolled 21 Crohn's disease patients having intestinal stricture. The patients consisted of 3 groups, which were the infliximab naïve (n = 6) group, the ustekinumab naïve (n = 8), and the bio-switch from infliximab to ustekinumab (n = 7) group. Bowell wall thickness was examined by ultrasound sonography, and the stiffness of Crohn's disease stricture lesions was evaluated using Shear wave speed before and 1 year after anti-tumor necrosis factor-alpha antibody infliximab, anti-interleukin 12/23 antibody ustekinumab, and bio-switch from infliximab to ustekinumab.

RESULTS

Bowell wall thickness was significantly improved after infliximab, ustekinumab, and the bio-switch. However, shear wave speed indices only in the ustekinumab group significantly decreased after treatment (P = .028), but not in the other group.

CONCLUSIONS

Shear wave elastography might be a useful method to evaluate stiffness in the areas of intestinal stricture in patients with Crohn's disease treated with biologics. However, a prospective randomized study evaluating the development of obstruction after biological treatment is needed to validate the study findings.

Can balloon-assisted enteroscopy predict disease outcomes in patients with small-bowel Crohn's disease?

There are limited studies on the endoscopic assessment of disease activity using balloon-assisted enteroscopy (BAE) and its predictive role for long-term outcomes of patients with small bowel Crohn's disease (CD). We sought to investigate the value of BAE as a predictor of long-term outcomes in patients with small-bowel CD. A total of 111 patients with small-bowel CD whose endoscopic disease activity was assessed using BAE based on the small-bowel simple endoscopic score for Crohn's disease (small-bowel SES-CD) at Samsung Medical Center were retrospectively selected from January 2014 to August 2020. The outcome was an evaluation of the risk of surgery according to a small-bowel SES-CD of 0-6 vs. ≥ 7 and endoscopic findings (presence of any ulcer and degree of stricture) using the Cox proportional hazards model. The risk of surgery was significantly increased in patients with a small-bowel SES-CD of ≥ 7 compared to a small-bowel SES-CD of 0-6 [hazard ratio (HR) 6.31; 95% confidence interval (CI) 1.48-26.91; p = 0.013]. In addition, the risk of surgery was significantly increased in patients with stenosis with "cannot be passed" compared to the cases without stenosis (HR 12.34; 95% CI 1.66-91.92; p = 0.014), whereas there was no significance in any ulcer. The present study demonstrated the role of BAE in the endoscopic assessment of disease activity and its predictive value for the risk of surgery in small-bowel CD patients. Further optimization of BAE utilization for the assessment of disease activity is warranted in clinical practice.

Viscoelastic properties of small bowel mesentery at MR elastography in Crohn's disease: a prospective cross-sectional exploratory study

BACKGROUND

Creeping fat is a pathological feature of small bowel Crohn's disease (CD), with literature suggesting that bowel resection with extended mesenteric resection is related to less postoperative recurrences. Conventional imaging is unable to accurately quantify the disease involvement (i.e., fibrosis) of creeping fat. Quantification of disease involvement could be useful in decision-making for additional extended mesenteric resection. We investigated the feasibility of magnetic resonance elastography (MRE) of the mesentery and if MRE is capable to detect fibrotic disease involvement of mesentery in active CD.

METHODS

Multifrequency MRE yielded spatial stiffness (shear wave speed, SWS, |G*|) and fluidity maps (φ). Viscoelastic properties of seven CD patients' mesentery were compared to age- and sex-matched healthy volunteers (HV) (Mann-Whitney U-test). Within CD patients, the affected and "presumably" unaffected mesentery were compared (Wilcoxon-signed rank test). Repeatability was tested in 15 HVs (Bland-Altman analysis, coefficient of variation [CoV]). Spearman rank correlations were used to investigate the relation between microscopically scored amount of mesenteric fibrosis and viscoelastic parameters.

RESULTS

SWS, |G*|, and φ of affected mesentery in CD were higher compared to HV (p = 0.017, p = 0.001, p = 0.017). Strong correlations were found between percentage of area of mesenteric fibrosis and SWS and |G*| (p < 0.010). No differences were found within CD between affected and presumably unaffected mesentery. Repeatability of SWS showed 95% limits of agreement of (-0.09, 0.13 m/s) and within-subject CoV of 5.3%.

CONCLUSION

MRE may have the potential to measure fibrotic disease involvement of the mesentery in CD, possibly guiding clinical decision-making with respect to extended mesenteric resection.

TRIAL REGISTRATION

Dutch trial register, NL9105 , registered 7 December 2020.

RELEVANCE STATEMENT

MRE may have the potential to measure the amount of mesenteric fibrosis of the affected mesenteric fat in active Crohn's disease, giving more insight into disease progression and could potentially play a role in clinical decision-making for extended mesenteric resection.

KEY POINTS

• MRE of the mesentery in patients with active CD is feasible. • Fluidity and stiffness of the mesentery increase in active CD, while stiffness correlates with the histopathological amount of mesenteric fibrosis. • MRE provides biomarkers to quantify mesenteric disease activity in active CD.

Magnetic Resonance Imaging Can Be Used to Assess Sarcopenia in Children with Newly Diagnosed Crohn's Disease

BACKGROUND

This study aimed to determine the proportion of patients with sarcopenia diagnosed by MRI and compare these results to bioelectrical impedance analysis (BIA).

METHODS

Children with newly diagnosed Crohn's disease (CD) who had MRI enterography (MRE) and BIA and had at least 12 months of follow-up were included. Total psoas muscle area (TPMA) and total paravertebral muscle (TPVM) were measured and compared to subjects' lean mass and the lean mass body index (LMBI) was assessed by BIA.

RESULTS

30 newly diagnosed children with CD were included (mean age 14.2 years, 53% male). Sarcopenia was found in 13 (43%) children; mean TPMA was 15.2 (1.1 SD) cm2 and TPVM 30.95 (1.7 SD) cm2. A highly positive correlation was shown for lean mass assessed by BIA and TPMA (0.706, p < 0.001) and TPVM (0.75, p < 0.001). Sarcopenia was more prevalent in boys (77% vs. 24%, p = 0.004), patients with the perianal disease (69% vs. 29%, p = 0.03), and children with sarcopenia were likely to receive anti-TNF (77% vs. 41%, p = 0.05). During the follow-up period, 16 (53%) children experienced a relapse. TPMA (HR 0.99, p = 0.018) and TPVM (HR 0.99, p = 0.031) values were statistically significant risk factors for relapse.

CONCLUSION

A high proportion of patients with CD have sarcopenia at the time of the diagnosis. There is a good correlation between muscle mass assessed by MRI and BIA. Because MRI is performed in a great proportion of newly diagnosed CD patients it can also be used to assess the presence of sarcopenia.

Computer-Aided Imaging Analysis of Probe-Based Confocal Laser Endomicroscopy With Molecular Labeling and Gene Expression Identifies Markers of Response to Biological Therapy in IBD Patients: The Endo-Omics Study

BACKGROUND

We aimed to predict response to biologics in inflammatory bowel disease (IBD) using computerized image analysis of probe confocal laser endomicroscopy (pCLE) in vivo and assess the binding of fluorescent-labeled biologics ex vivo. Additionally, we investigated genes predictive of anti-tumor necrosis factor (TNF) response.

METHODS

Twenty-nine patients (15 with Crohn's disease [CD], 14 with ulcerative colitis [UC]) underwent colonoscopy with pCLE before and 12 to 14 weeks after starting anti-TNF or anti-integrin α4β7 therapy. Biopsies were taken for fluorescein isothiocyanate-labeled infliximab and vedolizumab staining and gene expression analysis. Computer-aided quantitative image analysis of pCLE was performed. Differentially expressed genes predictive of response were determined and validated in a public cohort.

RESULTS

In vivo, vessel tortuosity, crypt morphology, and fluorescein leakage predicted response in UC (area under the receiver-operating characteristic curve [AUROC], 0.93; accuracy 85%, positive predictive value [PPV] 89%; negative predictive value [NPV] 75%) and CD (AUROC, 0.79; accuracy 80%; PPV 75%; NPV 83%) patients. Ex vivo, increased binding of labeled biologic at baseline predicted response in UC (UC) (AUROC, 83%; accuracy 77%; PPV 89%; NPV 50%) but not in Crohn's disease (AUROC 58%). A total of 325 differentially expressed genes distinguished responders from nonresponders, 86 of which fell within the most enriched pathways. A panel including ACTN1, CXCL6, LAMA4, EMILIN1, CRIP2, CXCL13, and MAPKAPK2 showed good prediction of anti-TNF response (AUROC >0.7).

CONCLUSIONS

Higher mucosal binding of the drug target is associated with response to therapy in UC. In vivo, mucosal and microvascular changes detected by pCLE are associated with response to biologics in inflammatory bowel disease. Anti-TNF-responsive UC patients have a less inflamed and fibrotic state pretreatment. Chemotactic pathways involving CXCL6 or CXCL13 may be novel targets for therapy in nonresponders.

Artificial intelligence in endoscopy: Overview, applications, and future directions

Since the emergence of artificial intelligence (AI) in medicine, endoscopy applications in gastroenterology have been at the forefront of innovations. The ever-increasing number of studies necessitates the need to organize and classify applications in a useful way. Separating AI capabilities by computer aided detection (CADe), diagnosis (CADx), and quality assessment (CADq) allows for a systematic evaluation of each application. CADe studies have shown promise in accurate detection of esophageal, gastric and colonic neoplasia as well as identifying sources of bleeding and Crohn's disease in the small bowel. While more advanced CADx applications employ optical biopsies to give further information to characterize neoplasia and grade inflammatory disease, diverse CADq applications ensure quality and increase the efficiency of procedures. Future applications show promise in advanced therapeutic modalities and integrated systems that provide multimodal capabilities. AI is set to revolutionize clinical decision making and performance of endoscopy.

New score models for assessing disease activity in Crohn's disease based on bowel ultrasound and biomarkers: Ideal surrogates for endoscopy or imaging

Disease activity evaluation is important in Crohn's disease (CD). We aimed to establish new disease activity indices for CD based on noninvasive parameters. The data of 110 patients with CD were retrospectively analyzed. Parameters from bowel ultrasound and biomarkers were measured to select the variables included in the models by univariate analysis. Logistic regression analysis was performed to predict mucosal and transmural activities defined by ileocolonoscopy or computed tomography enterography, respectively. The models' performance was measured by the area under the receiver operating characteristic (ROC) curve (AUC). Leave-one-out cross validation (LOOCV) was applied to adjust for overconfidence in the newly established score models. To predict mucosal activity, erythrocyte sedimentation rate (ESR) and (LimG × BWT)-SUM (the sum of the product of Limberg grade [LimG] and bowel wall thickness [BWT] of each bowel segment) were selected for model A, and the equation was A = 2 × ESR + 9.3 × (LimG × BWT)-SUM. The AUC of ROC, sensitivity, and specificity were 0.927%, 89.8%, and 86.4%, respectively. The AUC of the ROC curve verified by LOOCV was 0.913. To predict transmural activity, albumin (ALB) and LimG-SUM (the sum of the LimG of all the bowel segments) were selected for model B, which was established as B = -1.3 × ALB +1.7 × LimG-SUM. The AUC of ROC, sensitivity, and specificity were 0.851%, 78.0%, and 84.2%, respectively. The AUC of the ROC curve verified by LOOCV was 0.833. Nomograms were developed for two score models. New score models based on noninvasive parameters established in this study showed good abilities in detecting active disease and performed well in the validation phase.

Suboptimal Guideline Adherence and Biomarker Underutilization in Monitoring of Post-operative Crohn's Disease

BACKGROUND

Crohn's disease recurrence after ileocecal resection is common. Guidelines suggest colonoscopy within 6-12 months of surgery to assess for post-operative recurrence, but use of adjunctive monitoring is not protocolized. We aimed to describe the state of monitoring in post-operative Crohn's.

METHODS

We conducted a retrospective study of patients with Crohn's after ileocolic resection with ≥ 1-year follow-up. Patients were stratified into high and low risk based on guidelines. Post-operative biomarker (C-reactive protein, fecal calprotectin), cross-sectional imaging, and colonoscopy use were assessed. Biomarker, radiographic, and endoscopic post-operative recurrence were defined as elevated CRP/calprotectin, active inflammation on imaging, and Rutgeerts ≥ i2b, respectively. Data were stratified by surgery year to assess changes in practice patterns over time. P-values were calculated using Wilcoxon test and Fisher exact test.

RESULTS

Of 901 patients, 53% were female and 78% high risk. Median follow-up time was 60 m for LR and 50 m for high risk. Postoperatively, 18% low and 38% high risk had CRPs, 5% low and 10% high risk had calprotectins, and half of low and high risk had cross-sectional imaging. 29% low and 38% high risk had colonoscopy by 1 year. Compared to pre-2015, time to first radiography (584 days vs. 398 days) and colonoscopy (421 days vs. 296 days) were significantly shorter for high-risk post-2015 (P < 0.001). Probability of colonoscopy within 1 year increased over time (0.48, 2011 vs. 0.92, 2019).

CONCLUSION

Post-operative colonoscopy completion by 1 year is low. The use of CRP and imaging are common, whereas calprotectin is infrequently utilized. Practice patterns are shifting toward earlier monitoring.

CTE-Based Radiomics Models Can Identify Mucosal Healing in Patients with Crohn's Disease

RATIONALE AND OBJECTIVES

To develop computed tomography enterography (CTE)-based radiomics models to assess mucosal healing (MH) in patients with Crohn's disease (CD).

MATERIALS AND METHODS

CTE images were retrospectively collected from 92 confirmed cases of CD at the post-treatment review. Patients were randomly divided into developing (n = 73) and testing (n = 19) groups. Radiomics features were extracted from the enteric phase images, and the least absolute shrinkage and selection operator (LASSO) logistic regression was applied for feature selection using 5-fold cross-validation on the developing group. The selected features were further identified from the top-ranked features and used to create improved radiomics models. Machine learning models were constructed to compare radiomics models with different radiomics features. The area under the ROC curve (AUC) was calculated to assess the predictive performance for identifying MH in CD.

RESULTS

Among the 92 CD patients included in our study, 36 patients achieved MH. The AUC of the radiomics model 1, which was based on the 26 selected radiomics features, was 0.976 for evaluating MH in the testing cohort. The AUCs of radiomics models 2 and 4, based on the top 10 and top 5 positive and negative radiomics features, were 0.974 and 0.952 in the testing cohort, respectively. The AUC of the radiomics model 3, built by removing features with r > 0.5, was 0.956 in the testing cohort. The clinical utility of the clinical radiomics nomogram was confirmed by the decision curve analysis (DCA).

CONCLUSION

The CTE-based radiomics models have demonstrated favorable performance in assessing MH in patients with CD. Radiomics features can be used as a promising imaging biomarker for MH.

A Novel Radiomics Model Integrating Luminal and Mesenteric Features to Predict Mucosal Activity and Surgery Risk in Crohn's Disease Patients: A Multicenter Study

BACKGROUND

To investigate the feasibility of integrating radiomics and morphological features based on computed tomography enterography (CTE) for developing a noninvasive grading model for mucosal activity and surgery risk of Crohn's disease (CD) patients.

METHODS

A total of 167 patients from three centers were enrolled. Radiomics and image morphological features were extracted to quantify segmental and global simple endoscopic score for Crohn's disease (SES-CD). An image-fusion-based support vector machine (SVM) classifier was used for grading SES-CD and identifying moderate-to-severe SES-CD. The performance of the predictive model was assessed using the area under the receiver operating characteristic curve (AUC). A multiparametric model was developed to predict surgical progression in CD patients by combining sum-image scores and clinical data.

RESULTS

The AUC values of the multicategorical segmental SES-CD fusion radiomic model based on a combination of luminal and mesenteric radiomics were 0.828 and 0.709 in training and validation cohorts. The image fusion model integrating the fusion radiomics and morphological features could accurately distinguish bowel segments with moderate-to-severe SES-CD in both the training cohort (AUC = 0.847, 95% confidence interval (CI): 0.784-0.902) and the validation cohort (AUC = 0.896, 95% CI: 0.812-0.960). A predictive nomogram for interval surgery was developed based on multivariable cox analysis.

CONCLUSIONS

This study demonstrated the feasibility of integrating lumen and mesentery radiomic features to develop a promising noninvasive grading model for mucosal activity of CD. In combination with clinical data, the fusion-image score may yield an accurate prognostic model for time to surgery.

Reply to comment on "Ultrasonographic scores for ileal Crohn's disease assessment: better, worse or the same as contrast‑enhanced ultrasound?

We read the comments by Nylund K et al. regarding our paper "Ultrasonographic scores for ileal Crohn's disease assessment: Better, worse or the same as contrast‑enhanced ultrasound?". Intestinal ultrasound has become one of the most valuable developments in the past decade, a non-invasive, well-tolerated exam, with an easy repeatability, and absence of sedation, ionizing radiation, or preparation. Particularly for inflammatory bowel disease, where there is a lack of agreement of patient's symptoms with disease activity, in an era where the paradigm of mucosal healing is changing to transmural healing, and with the emergence of several therapies leading to repeated imaging surveillance, it is essential to highlight the role of intestinal ultrasound. Although intestinal ultrasound is an increasingly used tool to monitor inflammatory bowel disease activity, there is no widely accepted reproducible activity index, since the methodology for the development of the scores was shown to be insufficient in most studies and none have been adequately validated (Bots et al., J Crohns Colitis 12:920-9, 2018). In our study, we showed that the contrast-enhanced ultrasound (CEUS) peak enhancement derived from the time-intensity curve (TIC) is a promising non-invasive emerging method with a good accuracy to correlate clinical and endoscopic activity in the terminal ileum, superior to intestinal ultrasound scores relying on bowel wall thickness and colour Doppler.

Comment on "Ultrasonographic scores for ileal Crohn's disease assessment: better, worse or the same as contrast‑enhanced ultrasound?"

We read with interest the study by Freitas et al. comparing contrast-enhanced ultrasound (CEUS) and parameters from a time-intensity curve (TIC) with the SUS-CD score and IBUS-SAS score in patients with Crohn's disease (CD) undergoing gastrointestinal ultrasound (GIUS) and ileocolonoscopy. The aim was to compare the accuracy of CEUS and aforementioned scores in predicting terminal ileal inflammatory activity in patients with CD. In this retrospective study of 50 patients, inflammatory activity was defined as a segmental score of SES-CD ≥ 7 in the terminal ileum. The study found 30 patients with active endoscopic disease demonstrating no significant difference between the "inactive" and "active" SUS CD and IBUS-SAS scores. However, the CEUS peak enhancement derived from the TIC was shown to be significantly different. The authors conclude CEUS was superior for detecting inflammation in the terminal ileum, as opposed to ultrasound scores relying on bowel wall thickness and color Doppler.