Usefulness of abdominal ultrasonography in the analysis of endoscopic activity in patients with Crohn's disease: changes following treatment with immunomodulators and/or anti-TNF antibodies

Determining the Accuracy of Intestinal Ultrasound Scores as a Prescreening Tool in Crohn's Disease Clinical Trials

INTRODUCTION

High rates of screen failure for the minimum Simple Endoscopic Score for Crohn's Disease (SES-CD) plague Crohn's disease (CD) clinical trials. We aimed to determine the accuracy of segmental intestinal ultrasound (IUS) parameters and scores to detect segmental SES-CD activity.

METHODS

A single-center, blinded, cross-sectional cohort study of children and young adult patients with CD undergoing IUS and ileocolonoscopy, comparing segmental IUS bowel wall thickness (BWT), hyperemia (modified Limberg score [MLS]), and scores to detect segmental SES-CD activity: (i) SES-CD ≤2, (ii) SES-CD ≥6, and (iii) SES-CD ≥4 in the terminal ileum (TI) only. Primary outcome was accuracy of BWT, MLS, and IUS scores to detect SES-CD ≤2 and SES-CD ≥6. Secondary outcomes were accuracy of TI BWT, MLS, and IUS scores to detect SES-CD ≥4 and correlation with the SES-CD.

RESULTS

Eighty-two patients (median [interquartile range] age 16.5 [12.9-20.0] years) underwent IUS and ileocolonoscopy of 323 bowel segments. Segmental BWT ≤3.1 mm had a similar high accuracy to detect SES-CD ≤2 as IUS scores (area under the receiver operating curve [AUROC] 0.833 [95% confidence interval 0.76-0.91], 94% sensitivity, and 73% specificity). Segmental BWT ≥3.6 mm and ≥4.3 mm had similar high accuracy to detect SES-CD ≥6 (AUROC 0.950 [95% confidence interval 0.92-0.98], 89% sensitivity, 93% specificity) in the colon and an SES-CD ≥4 in the TI (AUROC 0.874 [0.79-0.96], 80% sensitivity, and 91% specificity) as IUS scores. Segmental IUS scores strongly correlated with the SES-CD.

DISCUSSION

Segmental IUS BWT is highly accurate to detect moderate-to-severe endoscopic inflammation. IUS may be the ideal prescreening tool to reduce unnecessary trial screen failures.

Intestinal Ultrasound and MRI for Monitoring Therapeutic Response in Luminal Crohn's Disease: A Systematic Review

PURPOSE

Cross-sectional imaging facilitates the assessment of transmural healing in patients with Crohn's disease. This systematic review addresses the utility of MRI and intestinal ultrasound (IUS) in the assessment of disease activity in response to drug therapy compared with endoscopy in patients with luminal Crohn's disease.

METHODS

Database searches were undertaken using predefined terms. Studies with ≥10 patients with luminal Crohn's disease with paired endoscopy and imaging (MRI or IUS) after treatment initiation were included. Publications were identified through searches of six bibliographic databases, all run on June 24, 2022. Records were screened on title and abstract, then full text, by two independent reviewers.

RESULTS

In total, 5,760 records were identified, with 24 studies meeting the inclusion criteria. Ten studies examined IUS and found good correlation between IUS and endoscopic remission (κ = 0.63-0.73). Early reduction in bowel wall thickness at 4 to 8 weeks predicted endoscopic response at 12 to 38 weeks (area under the receiver operating characteristic curve [AUROC], 0.77; odds ratio, 10.8; P = .01). Twelve studies examined MRI, with the Magnetic Resonance Index of Activity score having high accuracy for predicting endoscopic remission (AUROC, 0.97; sensitivity, 93%; specificity, 77%). A Simplified Magnetic Resonance Index of Activity score cutoff of ≥1 identifies active endoscopic disease (AUROC, 0.92; 95% confidence interval, 0.88-0.95; P < .0001).

CONCLUSIONS

IUS and MRI are both reliable, noninvasive modalities for assessing transmural healing in patients with Crohn's disease and are accurate in monitoring the response to drug therapy. These modalities can be used to monitor response to biologic induction therapy, with early changes predictive of response to treatment.

Intestinal ultrasound score predicts therapeutic outcomes of infliximab in pediatric patients with Crohn's disease

BACKGROUND AND AIMS

Objective evaluation of treatment response is critical in the management of Crohn's disease (CD). Compared with endoscopy, intestinal ultrasound (IUS) is non-invasive and well-tolerated. This study is aimed to assess the predictive value of IUS score for treatment response in pediatric CD patients.

METHODS

We conducted a retrospective study in pediatric CD patients who underwent endoscopy and IUS at start of infliximab treatment [T0] and after 22-38 weeks [T1] between February 2021 and January 2023. Pediatric Crohn's Disease Activity Index (PCDAI), biochemical parameters, the Simple Endoscopic Score for Crohn's disease (SES-CD) and IUS parameters were collected at two timepoints. IUS scores were assessed by International Bowel Ultrasound Segment Activity Score (IBUS-SAS).

RESULTS

Thirty patients were included, with 53.3% reaching endoscopic response and 43.3% endoscopic remission. After infliximab treatment, IBUS-SAS (58.5 ± 24.2 vs 34.4 ± 21.6, p = .0001) was significantly decreased. At T1, change in IBUS-SAS (-38.2 ± 22.0 vs -7.9 ± 24.1, p = .0015) were pronounced in patients with endoscopic response compared with endoscopic non-response. Significant correlation were observed between IBUS-SAS and SES-CD, PCDAI, C-reaction protein, erythrocyte sedimentation rate, hemoglobin, albumin. The most accurate cutoff values for predicting endoscopic response were 57.4% decrease of IBUS-SAS (AUROC: 0.862, p < .001). The optimal cut-off of IBUS-SAS to correlate endoscopic remission was 26.0 (AUROC: 0.686, p = .017).

CONCLUSIONS

The validated ultrasound-base score, IBUS-SAS is an effective index for monitoring endoscopic response to infliximab therapy in CD. IUS evaluation could guide treatment decision for pediatric CD.

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.

Submucosal fat accumulation in Crohn's disease: evaluation with sonography

BACKGROUND/AIMS

The study objective is to investigate the ultrasound features that allow suspecting the presence of submucosal fat deposition, called the fat halo sign (FHS), in the intestinal wall of patients with Crohn's disease.

METHODS

Computed tomography (CT) examinations over a period of 10 years were reviewed for the presence of the FHS in the bowel wall. A measurement of less than -10 Hounsfield units was regarded as indicative of fat. We included only patients who had undergone ultrasound examinations 3 months before or after CT. The study cohort group comprised 68 patients. Wall and submucosal thickness were measured on longitudinal ultrasound sections. A receiver operating characteristic curve was constructed to determine the best cutoff of ultrasound submucosal wall thickness value for predicting FHS in the bowel wall determined on CT.

RESULTS

The FHS was present in 22 patients (31%) on CT. There were significant differences between submucosal thickness of patients with FHS and patients without FHS (4.19 mm vs. 2.41 mm). From the receiver operating characteristic curve, a threshold value of 3.1 mm of submucosal thickness had the best sensitivity and specificity to suspect FHS (95.5% and 89.1%, respectively; area under the curve, 0.962), with an odds ratio of 172. All of 16 patients with a submucosal thickness >3.9 mm had FHS.

CONCLUSIONS

FHS in patients with Crohn's disease can be suspected on ultrasound in cases with marked thickening of the submucosa layer. In these cases, the activity of the disease should be measured by other parameters such as the color Doppler.

Transmural or mucosal healing in Crohn´s disease. Which is the goal to be pursued?

In their original report of regional ileitis, Crohn, Ginzburg and Oppenheimer already described that inflammation involved not only the ileal mucosa: "the submucosal and, to a much lesser extent, the muscular layers of the bowel are the seat of marked inflammatory hyperplastic and exudative changes", they wrote 1. Ninety years later it is well established that the inflammatory process that characterizes Crohn´s disease (CD) involves all the layers of the intestinal wall; this fact is directly related with the development of progressive digestive tract damage related to disabling complications such as strictures, fistulae, perforation, and perianal or abdominal abscesses.

Early Ultrasound Response and Progressive Transmural Remission After Treatment With Ustekinumab in Crohn's Disease

BACKGROUND & AIMS

In this STARDUST substudy, the effect of ustekinumab on transmural bowel inflammation was assessed in adults with moderate-to-severe Crohn's disease (CD) by using intestinal ultrasound (IUS), a noninvasive imaging procedure.

METHODS

STARDUST was an international, multicenter, phase 3b, interventional, randomized controlled trial specifically designed to compare treat-to-target and standard-of-care treatment strategies in ustekinumab-treated CD patients. In this substudy, the most affected bowel segment at baseline by IUS was used for all analyses. Key IUS endpoints (centrally read, parameter-blinded) were IUS response, transmural remission, bowel wall thickness (BWT), blood flow, bowel wall stratification, and inflammatory fat.

RESULTS

Seventy-seven patients were evaluated. IUS response could be determined 4 weeks after treatment initiation, with progressive improvement through week 48. IUS response and transmural remission rates at week 48 were 46.3% and 24.1%, respectively. IUS response, transmural remission, BWT, and blood flow normalization rates were more pronounced in the colon and biologic-naive patients. Fair/moderate reliability (κ = 0.21-0.51) was observed between week 4 IUS response and week 48 overall endoscopic response and fecal calprotectin/complete biomarker outcomes. Endoscopy and IUS baseline agreement was >90% in determining the terminal ileum as the most affected bowel segment. IUS response absence at week 4 was associated with no endoscopic response (based on the simplified endoscopic score for Crohn's disease terminal ileum subscore) at week 48 (negative predictive value = 73%).

CONCLUSIONS

In this first international, multicenter, interventional study, IUS showed that ustekinumab-treated CD patients achieved progressive IUS response (46.3%) and transmural remission (24.1%) through week 48, with a more robust response in the colon and biologic-naive patients.

CLINICALTRIALS

gov number: NCT03107793.

Characteristics and usefulness of transabdominal ultrasonography in immune-mediated colitis

BACKGROUND/AIMS

The usefulness of ultrasonography (US) in diseases of the gastrointestinal tract has been reported recently. This prospective study aimed to determine the features of US findings in immune-mediated colitis (IMC), an adverse event induced by immune checkpoint inhibitor, and examine the correlation between US findings, colonoscopy (CS) findings, and severity of colitis.

METHODS

We studied patients examined using CS and US upon suspicion of IMC in Hokkaido University Hospital between April 2018 and February 2021. Endoscopic findings of IMC were assessed using the Ulcerative Colitis Endoscopic Index of Severity (UCEIS). The severity of US findings in IMC was evaluated using US grade, which is the ultrasonographic grading scale in ulcerative colitis. Bowel wall thickness and the intensity of the color Doppler signal were also analyzed. Severity of colitis was evaluated using Common Terminology Criteria for Adverse Events (CTCAE) grade version 5.

RESULTS

Fourteen patients with IMC were enrolled. The US findings were bowel wall thickening, loss of stratification, ulceration and increased blood flow signal. The US grade was moderately correlated with the UCEIS (r=0.687, p=0.009) and CTCAE grade (r=0.628, p=0.035). Bowel wall thickness and UCEIS (r=0.628, p=0.020), as well as color Doppler signal grade and CTCAE grade (r=0.724, p=0.008), were significantly correlated.

CONCLUSIONS

US findings in IMC were mainly similar to those of ulcerative colitis, but there were some findings that were characteristic only of IMC. Significant correlation was found between US findings, CS findings, and severity of colitis. Hence, US could be useful for the evaluation of IMC.

Medication use among patients with Crohn’s disease or ulcerative colitis before and after the initiation of advanced therapy

Background

Although various treatments help reduce abdominal pain, real-world pain medication utilization among patients with Crohn’s disease (CD) or ulcerative colitis (UC) receiving advanced therapies is poorly understood. The aim is to understand the utilization of pain medication 12 months before and after the initiation of advanced therapies among patients with newly diagnosed CD or UC.

Methods

This retrospective, observational cohort study used administrative medical and pharmacy claims data of patients with CD or UC from HealthCore Integrated Research Database (HIRD®). The data from patients with use of pain medication over 12 months follow-up (after the initiation date of advanced therapies) were collected and analyzed. Differences in the use of pain medication 12 months before and after the initiation of advanced therapies were assessed using McNemar's and Wilcoxon signed-rank test.

Results

Prior to initiating advanced therapies, 23.1% of patients with CD (N = 540) received nonsteroidal anti-inflammatory drugs (NSAIDs), 78.1% glucocorticoids, 49.4% opioids, and 29.3% neuromodulators; similarly, 20.9% of patients with UC (N = 373) received NSAIDs, 91.4% glucocorticoids, 40.8% opioids, and 29.5% neuromodulators. After receiving advanced therapies for 12 months, patients reported a reduction in the use of steroids (78.1% vs. 58.9%, P < 0.001 in CD; 91.4% vs. 74.3%, P < 0.001 in UC), opioids (49.4% vs. 41.5%, P = 0.004 in CD; 40.8% vs. 36.5%, P = 0.194 in UC), and NSAIDs (23.1% vs. 15.0%, P < 0.001 in CD; 20.9% vs. 15.8%, P = 0.035 in UC), while the use of neuromodulators significantly increased (29.3% vs. 33.7%, P = 0.007 in CD; 29.5% vs. 35.7%; P = 0.006 in UC).

Conclusions

The use of pain medications such as NSAIDs, glucocorticoids, opioids, and neuromodulators was common among patients with CD or UC. These results highlight that patients with CD or UC continued to receive pain medications even after initiating advanced therapies.

Intestinal Ultrasound in the Assessment of Luminal Crohn’s Disease

Crohn’s disease is a chronic inflammatory disease affecting the gastrointestinal tract. Expert guidelines now recommend regular objective assessments as part of a treat-to-target approach. Intestinal ultrasound provides a noninvasive, patient-friendly modality for assessing Crohn’s disease without the risk of radiation exposure and does not require fasting or bowel preparation. Enhancement techniques, including oral and intravenous contrast, can improve disease-activity and complication detection. Due to its acceptability, intestinal ultrasound can be performed frequently, allowing for closer disease-activity monitoring and treatment adjustments. There have been significant advances in the utility of intestinal ultrasound; particularly for assessing disease activity during pregnancy and fibrosis detection utilising elastography. This review provides a comprehensive overview of performing intestinal ultrasound, the diagnostic accuracy, role in disease-activity monitoring, and recent advances in utilising ultrasound for the assessment of luminal Crohn’s disease.

Longitudinal Bowel Behavior Assessed by Bowel Ultrasound to Predict Early Response to Anti-TNF Therapy in Patients With Crohn's Disease: A Pilot Study

BACKGROUND

Early changes in bowel behavior during anti-tumor necrosis factor (anti-TNF) induction therapy in Crohn's disease (CD) are relatively unknown. We determined (1) the onset of changes in bowel behavior in CD patients receiving anti-TNF therapy by ultrasound and (2) the feasibility of shear wave elastography (SWE) in predicting early response to anti-TNF therapy.

METHODS

Consecutive ileal or ileocolonic CD patients programmed to initiate anti-TNF therapy were enrolled. Bowel ultrasound was performed at baseline and at weeks 2, 6, and 14. Changes in bowel wall thickness, Doppler signals of the bowel wall (Limberg score), and SWE values were compared using a linear mixed model. Early response to anti-TNF therapy was based on a composite strategy of clinical and colonoscopy assessment at week 14.

RESULTS

Of the 30 patients enrolled in this study, 20 patients achieved a response to anti-TNF therapy at week 14. The bowel wall thickness and SWE value of the response group showed a significant downward trend compared with the nonresponse group (P = .003 and P = .011, respectively). Bowel wall thickness, the Limberg score, and SWE values were significantly reduced as early as week 2 compared with baseline (P < .001, P < .001, and P = .003, respectively) in the response group. Baseline SWE values (21.3 ± 8.7 kPa vs 15.3 ± 4.7 kPa; P = .022) and bowel wall thickness (8.5 ± 2.3 mm vs 6.9 ± 1.5 mm; P = .027) in the nonresponse group were significantly higher than in the response group.

CONCLUSIONS

This pilot study suggested that changes in bowel ultrasound behavior could be assessed as early as week 2 after starting anti-TNF therapy. Bowel ultrasound together with elasticity imaging could predict early response to anti-TNF therapy.

Early sonographic response to a new medical therapy is associated with future treatment response or failure in patients with inflammatory bowel disease

OBJECTIVE

Gastrointestinal ultrasound (GIUS) accurately assesses inflammation and is responsive to changes in inflammatory bowel disease. This study aimed to determine the prognostic utility of sonographic response in the first 14 weeks of a newly-instituted therapy with therapeutic response at 46 weeks and to compare its performance with standard clinical assessment tools.

METHODS

Patients with sonographic evidence of inflammation were assessed by GIUS, clinical activity, serum C-reactive protein and faecal calprotectin again 2, 6 and 14 weeks after commencing a new biologic or thiopurine. Treatment failure was defined as undergoing surgery, hospitalisation, escalation of dosage or introduction of new medication over 46-weeks' follow-up. Sonographic response was defined as a decrease in bowel wall thickness and improved vascularity.

RESULTS

In 31 patients (median age 49 years, 74% Crohn's disease), sonographic response at 14 weeks [OR 19.3, 95% confidence interval (CI), 3.23-101.10; P = 0.0054] and faecal calprotectin (P = 0.018), but no clinical disease activity or C-reactive protein, were predictive of subsequent treatment response. Sonographic response alone was predictive at week 6 (P = 0.016), but not week 2. 16% reduction in bowel wall thickness at 6 weeks (area-under-the-receiver-operator-curve=0.86; P = 0.002; sensitivity 72%, specificity 90%), with similar performance for 10% at 14 weeks, was associated with treatment response.

CONCLUSION

Sonographic response as early as 6 weeks after initiation of a new therapy may accurately predict treatment outcomes over 46 weeks and is superior to other markers used to monitor disease activity.

Intestinal Ultrasound Early on in Treatment Follow-up Predicts Endoscopic Response to Anti-TNFα Treatment in Crohn's Disease

BACKGROUND

To assess treatment response, objective measures are superior to clinical improvement in Crohn's disease [CD]. Intestinal ultrasound [IUS] is an attractive, non-invasive alternative to endoscopy, demonstrating early transmural changes after treatment initiation. Therefore, we investigated IUS and contrast-enhanced ultrasound [CEUS] to predict [early] endoscopic treatment response.

METHODS

Consecutive patients with endoscopically active CD, starting anti-TNFα therapy, were included. Clinical, biochemical, IUS, and CEUS parameters at baseline [T0], after 4-8 weeks [T1] and 12-34 weeks [T2] were collected. The most severely inflamed segment at endoscopy (highest segmental Simplified Endoscopic Score for Crohn's Disease [SES-CD]) and IUS (highest segmental bowel wall thickness [BWT]) was identified. At T2, endoscopic response [decrease in SES-CD ≥ 50%] and remission [SES-CD = 0] were scored.

RESULTS

A total of 40 patients were included: 14 reached endoscopic remission and 17 endoscopic response. At T1 (3.1 mm [1.9-4.2] vs 5.3 mm [3.8-6.9], p = 0.005) and T2 (2.0 mm [1.8-3.1] vs 5.1 [3.0-6.3] mm, p = 0.002) BWT was lower in patients with endoscopic remission. At T1 and T2, 18% (area under the receiver operating curve [AUROC]: 0.77; odds ratio [OR]: 10.80, p = 0.012) and 29% [AUROC: 0.833; OR: 37.50, p = 0.006] BWT decrease predicted endoscopic response, respectively. To determine endoscopic remission, BWT 3.2 mm was most accurate [AUROC: 0.94; OR: 39.42, p < 0.0001] at T2. In addition, absence of colour Doppler signal [OR: 13.76, p = 0.03] and the CEUS parameter wash-out rate [OR: 0.76, p = 0.019] improved the prediction model.

CONCLUSIONS

Reduction in BWT, already after 4-8 weeks of follow-up, predicted endoscopic response and remission. CEUS parameters were of limited value. Furthermore, we have provided accurate cut-offs for BWT reflecting endoscopic response and remission at different time points.

ECCO-ESGAR Topical Review on Optimizing Reporting for Cross-Sectional Imaging in Inflammatory Bowel Disease

BACKGROUND AND AIMS

The diagnosis and follow up of patients with inflammatory bowel disease [IBD] requires cross-sectional imaging modalities, such as intestinal ultrasound [IUS], magnetic resonance imaging [MRI] and computed tomography [CT]. The quality and homogeneity of medical reporting are crucial to ensure effective communication between specialists and to improve patient care. The current topical review addresses optimized reporting requirements for cross-sectional imaging in IBD.

METHODS

An expert consensus panel consisting of gastroenterologists, radiologists and surgeons convened by the ECCO in collaboration with ESGAR performed a systematic literature review covering the reporting aspects of MRI, CT, IUS, endoanal ultrasonography and transperineal ultrasonography in IBD. Practice position statements were developed utilizing a Delphi methodology incorporating two consecutive rounds. Current practice positions were set when ≥80% of the participants agreed on a recommendation.

RESULTS

Twenty-five practice positions were developed, establishing standard terminology for optimal reporting in cross-sectional imaging. Assessment of inflammation, complications and imaging of perianal CD are outlined. The minimum requirements of a standardized report, including a list of essential reporting items, have been defined.

CONCLUSIONS

This topical review offers practice recommendations to optimize and homogenize reporting in cross-sectional imaging in IBD.

Gastrointestinal Ultrasound Can Predict Endoscopic Activity in Crohn's Disease

PURPOSE

 To explore the ability of gastrointestinal ultrasound (GIUS) to separate patients in endoscopic remission from patients with active disease in a heterogeneous hospital cohort with Crohn's disease (CD).

MATERIALS AND METHODS

 145 CD patients scheduled for ileocolonoscopy were prospectively included. The endoscopic disease activity was quantified using the Simple Endoscopic Score for Crohn's disease (SES-CD), and mucosal healing was strictly defined as SES-CD = 0. Ultrasound remission was defined as wall thickness < 3 mm (< 4 mm in the rectum). Additionally, SES-CD was compared to color Doppler, Harvey Bradshaw's index (HBI), C-reactive protein (CRP) and calprotectin. 23 patients were examined by two investigators for interobserver assessment.

RESULTS

 102 had active disease and 43 patients were in remission. GIUS yielded a sensitivity of 92.2 % and a specificity of 86 % for wall thickness and a sensitivity of 66.7 % and a specificity of 97.7 % for color Doppler. The sensitivity and specificity were 34.3 % and 88.4 %, respectively, for HBI, 35.7 % and 82.9 %, respectively, for CRP and 55.9 % and 82.1 %, respectively, for calprotectin. The interobserver analysis revealed excellent agreement for wall thickness (k = 0.90) and color Doppler (k = 0.91) measurements.

CONCLUSION

 GIUS has a high sensitivity for detecting endoscopic activity. Accordingly, bowel ultrasound has the potential to reduce the number of routine ileocolonoscopies in patients with CD.

Bowel ultrasound score is accurate in assessing response to therapy in patients with Crohn's disease

BACKGROUND

We developed a non-invasive bowel ultrasound score (BUSS) to assess disease activity in Crohn's disease (CD). BUSS >3.52 is an indicator of endoscopic activity (SES-CD>2).

AIM

To assess whether BUSS, in addition to detecting inflammatory lesions, also detects relevant changes of these lesions over time.

METHODS

This was a prospective observational study of 49 patients with active CD. All patients underwent bowel ultrasound and colonoscopy at baseline and at re-assessment after treatment with biologics and/or immunosuppressants. The primary objective was to assess the sensitivity to change of BUSS in patients treated for active CD, using the SES-CD as reference standard.

RESULTS

BUSS changed significantly from baseline to re-assessment in patients achieving endoscopic response (a reduction of SES-CD of at least 50% vs baseline: 4.87 [3.78-6.0] vs 2.47 [2.25-3.36], P < 0.001) and endoscopic remission (SES-CD ≤ 2: 4.65 [3.58-6.03] vs 2.25 [2.25-3.46], P = 0.003). A change of -1.2 in BUSS over time predicted endoscopic response (AUC 0.786, 95% CI 0.645-0.890; sensitivity 74%, specificity 83%). BUSS determined endoscopic response with 80% accuracy, and endoscopic remission with 78% accuracy. BUSS accurately detected changes in lesion severity (Guyatt score: 1.41 and standardized effect score: 1.74). BUSS did not change significantly in patients who did not achieve endoscopic response (5.62 [5.26-6.15] vs 5.70 [4.97-6.19], P = 0.53) or endoscopic remission (5.62 [5.18-6.14] vs 5.10 [4.58-6.05]; P = 0.10).

CONCLUSION

BUSS is sensitive to change in CD.

Cross-Sectional Imaging Instead of Colonoscopy in Inflammatory Bowel Diseases: Lights and Shadows

International guidelines recommend a treat-to-target strategy with a close monitoring of disease activity and therapeutic response in inflammatory bowel diseases (IBD). Colonoscopy (CS) represents the current first-line procedure for evaluating disease activity in IBD. However, as it is expensive, invasive and poorly accepted by patients, CS is not appropriate for frequent and repetitive reassessments of disease activity. Recently, cross-sectional imaging techniques have been increasingly shown as reliable tools for assessing IBD activity. While computed tomography (CT) is hampered by radiation risks, routine implementation of magnetic resonance enterography (MRE) for close monitoring is limited by its costs, low availability and long examination time. Novel magnetic resonance imaging (MRI)-based techniques, such as diffusion-weighted imaging (DWI), can overcome some of these weaknesses and have been shown as valuable options for IBD monitoring. Bowel ultrasound (BUS) is a noninvasive, highly available, cheap, and well accepted procedure that has been demonstrated to be as accurate as CS and MRE for assessing and monitoring disease activity in IBD. Furthermore, as BUS can be quickly performed at the point-of-care, it allows for real-time clinical decision making. This review summarizes the current evidence on the use of cross-sectional imaging techniques as cost-effective, noninvasive and reliable alternatives to CS for monitoring patients with IBD.

Crohn's Disease Activity Evaluation by Transabdominal Ultrasonography: Correlation with Double-Balloon Endoscopy

OBJECTIVES

Transabdominal ultrasonography (US) has been reported as a useful tool for evaluating Crohn's disease (CD) activity. Endoscopic findings and Crohn's disease activity index (CDAI) are currently considered the gold standard for assessing CD activity. We assessed the correlation between US and double-balloon endoscopy (DBE), and CDAI for evaluating CD activity.

METHODS

We analyzed patients with CD undergoing US and DBE within 10 days between the procedures. The intestine was divided into four segments and analyzed by the US scoring system (US-CD) and the simple endoscopic score for Crohn's disease (SES-CD). CDAI was compared with US-CD and SES-CD. Spearman's rank correlation coefficient was used for statistical analysis.

RESULTS

Twenty-five patients with CD (11 women, 14 men; mean age 35.4 ± 14.9 years, range 16-65 years) were enrolled. Twenty-four patients received antitumor necrosis factor inhibitor therapy. CDAI was 128.1 (range 36-227). A significant moderate correlation was found between the US-CD and SES-CD in all segments (ρ = .64, P < .01). The US-CD showed a strong correlation with CDAI (ρ = .78, P < .01), whereas the SES-CD showed a moderate correlation (ρ = .55, P < .05).

CONCLUSIONS

US-CD and SES-CD showed a moderate correlation for assessing CD activity. US-CD showed a stronger correlation with CDAI than SES-CD, suggesting that US could more accurately evaluate the disease activity.

Current noninvasive modalities in Crohn's disease monitoring

Crohn’s disease (CD) is characterized by a remitting and relapsing course. Longstanding active CD may result in accumulating intestinal damage and disease-related complications. In contrast, mucosal healing is associated with significant improvement in the health-related quality of life, longer periods of disease remission and lower risk of disease progression, complications, hospitalizations, intestinal surgeries, as well as a lower risk of developing colorectal cancer. Mucosal healing, the new treatment endpoint in CD, made necessary the development of noninvasive, accurate, objective and reliable tools for the evaluation of CD activity. Ileocolonoscopy with biopsies remains the reference standard method for the evaluation of the colonic and terminal ileal mucosa. However, it is an invasive procedure with a low risk of complications, allowing the investigation of only a small part of the small bowel mucosa without being able to assess transmural inflammation. These disadvantages limit its role in the frequent follow up of CD patients. In this review, we present the currently available biomarkers and imaging modalities for the noninvasive assessment of CD activity.

Point-of-care Intestinal Ultrasound in IBD Patients: Disease Management and Diagnostic Yield in a Real-world Cohort and Proposal of a Point-of-care Algorithm

INTRODUCTION

Intestinal ultrasound [IUS] is useful for assessment of inflammation, complications, and treatment follow-up in inflammatory bowel disease [IBD] patients. We aimed to study outcomes and impact on disease management for point-of-care [POC] IUS in IBD patients.

METHODS

Two patient cohorts undergoing POC IUS [January 2016-July 2018 and October 2019-December 2019] were included retrospectively. Disease management after IUS was analysed and IUS outcomes were compared with symptoms, biomarkers, and additional imaging within 8 weeks from IUS. To study differences in use of IUS over time, cohorts were compared.

RESULTS

In total, 345 examinations (280 in Crohn's disease [CD]/65 in ulcerative colitis [UC]) were performed. Present inflammation on IUS was comparable between symptomatic and asymptomatic CD [67.6% vs 60.5%; p = 0.291]. In 60%, IUS had impact on disease management with change in medication in 47.8%. Additional endoscopy/magnetic resonance imaging [MRI] was planned after 32.8% examinations, showing good correlation with IUS in 86.3% [ρ = 0.70, p <0.0001] and 80.0% [ρ = 0.75, p <0.0001] of cases, respectively. Faecal calprotectin was higher in active versus inactive disease on IUS [664 µg/g vs 79 µg/g; p <0.001]. Over the years, IUS was performed more frequently to monitor treatment response and the use of MRI was reduced within the cohort.

CONCLUSIONS

POC IUS affects clinical decision making and could detect preclinical relapse in CD patients, with potential to reduce additional endoscopy or MRI. In addition, the paradigm expands towards monitoring treatment and close follow-up for IUS. Based on our results, we propose a POC IUS algorithm for follow-up of IBD patients.

Defining Transabdominal Intestinal Ultrasound Treatment Response and Remission in Inflammatory Bowel Disease: Systematic Review and Expert Consensus Statement

BACKGROUND AND AIMS

No consensus exists on defining intestinal ultrasound response, transmural healing, or transmural remission in inflammatory bowel disease, nor clear guidance for optimal timing of assessment during treatment. This systematic review and expert consensus study aimed to define such recommendations, along with key parameters included in response reporting.

METHODS

Electronic databases were searched from inception to July 26, 2021, using pre-defined terms. Studies were eligible if at least two intestinal ultrasound [IUS] assessments at different time points during treatment were reported, along with an appropriate reference standard. The QUADAS-2 tool was used to examine study-level risk of bias. An international panel of experts [n = 18] rated an initial 196 statements [RAND/UCLA process, scale 1-9]. Two videoconferences were conducted, resulting in additional ratings of 149 and 13 statements, respectively.

RESULTS

Out of 5826 records, 31 full-text articles, 16 abstracts, and one research letter were included; 83% [40/48] of included studies showed a low concern of applicability, and 96% [46/48] had a high risk of bias. A consensus was reached on 41 statements, with clear definitions of IUS treatment response, transmural healing, transmural remission, timing of assessment, and general considerations when using intestinal ultrasound in inflammatory bowel disease.

CONCLUSIONS

Response criteria and time points of response assessment varied between studies, complicating direct comparison of parameter changes and their relation to treatment outcomes. To ensure a unified approach in routine care and clinical trials, we provide recommendations and definitions for key parameters for intestinal ultrasound response, to incorporate into future prospective studies.

Prognostic value of ultrasound activity and parietal healing in patients with Crohn's disease

INTRODUCTION

the "treat to target" strategy for the management of patients with Crohn's disease (CD) requires simple, reliable and non-invasive tools for continuous monitoring of the disease. Intestinal ultrasound has been proposed as an emerging technique that could be very useful in this field.

MATERIAL AND METHODS

patients who had undergone an intestinal ultrasound in the clinical practice between February 2013 and October 2018 at our hospital were retrospectively included. The evolution of the patients during follow-up was assessed based on the presence of ultrasound activity and the therapeutic changes based on the results.

RESULTS

two hundred and seventy-seven CD patients were included and the median follow-up time was 24 months (range 5-73 months). Signs of ultrasound inflammatory activity were identified in 166 patients (60 %), and of them, treatment was escalated in 116 patients (70 %) based on the results of the ultrasound. Among patients with identified ultrasound activity, in 166 patients (60 %) the evolution was less favorable than in those without activity, with a shorter time until the next outbreak. Thus, the median disease-free survival (without outbreaks) after performing the ultrasound was 18 months when ultrasound activity was identified (although in most of the patients [70 %] the treatment had been escalated) vs 47 months in patients without ultrasound activity. However, these differences were not statistically significant (p < 0.0001). Among the 111 patients without ultrasound activity, those who achieved "parietal healing" (74 patients) had a better evolution with a 12 % subsequent outbreak vs 27 % during follow-up (p = 0.05). Thus, 15 % of patients with parietal healing had an outbreak vs 34 % of those who had not normalized the ultrasound findings after three years of follow-up.

CONCLUSION

intestinal ultrasound is a technique capable of detecting inflammatory activity in patients with Crohn's disease and the presence of ultrasound activity is a risk factor for a new outbreak of activity and/or clinical relapse. Likewise, the presence of "parietal or transmural healing" (PH) is associated with a better evolution of patients during follow-up. Thus, it could be a more precise objective to consider deep remission in CD, with intestinal ultrasound being a useful technique for this purpose.

Qualitative sonographic assessment of transmural ileal inflammation in Crohn's disease: a comparison with MRI activity score

BACKGROUND

Intestinal ultrasound (IUS) is an accurate tool for monitoring Crohn's disease. To date, there is no clinically used validated quantitative ultrasonographic score for assessing disease activity. For magnetic resonance enterography (MRE), the magnetic resonance index of activity (MaRIA) is most used. The goal of this study was to devise a new quantitative IUS score for assessing Crohn's disease inflammation, by using a partial MaRIA score as a reference.

METHODS

This was a retrospective cohort study. The study cohort included patients with Crohn's disease followed between January 2016 and December 2018. Inclusion criteria were age >18 and <3 months between MRE and IUS. Linear/logistic regression was performed for the correlation of ultrasonographic parameters with MaRIA score. Ultrasonograpic features included: bowel wall thickness, disrupted bowel wall stratification, mesenteric fat proliferation, presence of lymph nodes, hypervascularity present on color Doppler flow, and the presence of complications (strictures, inflammatory mass, and fistula).

RESULTS

Forty-two patients were included. A stepwise multiple regression model was constructed to predict MaRIA score using ultrasound features. Two variables were found to be independently significant: terminal ileum (TI) thickness (r = 0.68, P = 0.001) and mesenteric fat proliferation (r = 0.45, P = 0.019). A model was constructed as follows: MaRIA = 7 + 2.5 * TI US thickness (mm) + 7 * US fat proliferation (0 = no, 1 = yes). This model has an R2 of 0.51 for explaining the variability in the results.

CONCLUSIONS

IUS measurements are significantly correlated with MaRIA score in the terminal ileum and a simple computational model can be constructed.

Transmural healing as a therapeutic goal in Crohn's disease: a systematic review

Transmural healing is associated with substantial improvements in disease-related outcomes for patients with Crohn's disease, but there is no single validated definition of transmural healing to date. We did a systematic review to summarise the available definitions and to evaluate the effect of transmural healing on disease-related outcomes for patients with Crohn's disease by searching PubMed, Cochrane Library, and Web of Science for interventional and non-interventional studies. Seventeen studies were included, reporting rates of transmural healing in between 14·0% and 42·4% of patients. Transmural healing was assessed with magnetic resonance enterography, bowel sonography, or CT enterography. Most studies used bowel wall thickness, with 3 mm or less as the most frequent cutoff, to define transmural healing. Vascularisation assessed by doppler ultrasound and absence of complications or contrast enhancement were also used for this definition. Transmural healing was significantly associated with improvements in disease-related outcomes. In addition, there was a good correlation between transmural healing, mucosal healing, and selected biomarkers. We conclude that bowel wall thickness is the most frequently used item to evaluate transmural healing, which is associated with improvements in long-term outcomes of Crohn's disease and should be considered as a new treatment target.

The role of the intestinal ultrasound in Crohn's disease diagnosis and monitoring

Crohn's disease is characterized by persistent or recurrent chronic inflammation that may affect any segment of the gastrointestinal tract. It has an oscillating evolution, with periods of activity alternating with periods of remission. Crohn's disease has a significant impact on the economic status due to its increasing prevalence, often affecting young people. Suitable management for these patients involves frequent evaluations. Even though colonoscopy is the gold standard for the assessment of severity and mucosal healing, it is an invasive maneuver, not easily accepted by patients, and it does not have good repeatability. Intestinal ultrasound has the advantage of being non-irradiating, non-invasive, well-tolerated, cheap, and easy to repeat. Ultrasound parameters such as bowel wall thickness, intestinal wall architecture, intramural vascularisation, proliferation of mesenteric fatty conjunctive tissue, and intraperitoneal fluid can provide good information regarding the severity of the disease, the differentiation between remission and relapse, and its complications. Some of the latest studies show good correlations between ultrasound parameters and inflammation markers (C-reactive protein, fecal calprotectin) and clinical severity scores of Crohn's disease. Consequently, the importance of intestinal ultrasound has increased lately, and recent studies support its use to evaluate the severity of inflammation, differentiate between active disease and relapse, monitor therapy response and guide treatment, evaluate prognosis, and diagnose complications.

Use of Small Bowel Ultrasound to Predict Response to Infliximab Induction in Pediatric Crohn's Disease

GOAL

The goal of this study was to explore the utility of small bowel ultrasound (SBUS) as a noninvasive tool to assess induction response to infliximab (IFX) in pediatric Crohn's disease (CD).

BACKGROUND

Inflammatory bowel disease management has shifted to a treat-to-target and tight control strategy utilizing noninvasive serum and fecal markers to monitor disease activity in response to therapy. Bowel wall changes as seen on cross-sectional imaging may be a more accurate marker of treatment success.

MATERIALS AND METHODS

Pediatric patients with CD with small bowel involvement initiating IFX were prospectively enrolled. Clinical activity, biomarkers, and SBUS findings were evaluated at baseline (T0) and postinduction at week 14 (T1). The primary outcome was to describe the changes in SBUS parameters pre and post IFX induction and how they associate with clinical and biomarker response. Descriptive statistics summarized the data and univariate analysis tested associations.

RESULTS

All 13 CD patients achieved steroid-free clinical remission (P<0.001) and a decrease in C-reactive protein (P=0.01) postinduction. Bowel wall hyperemia (BWH) (P=0.01) and bowel segment length involved (P=0.07) decreased postinduction. Decrease in fecal calprotectin at T1 moderately correlated with a decrease in bowel segment length (r=0.57; P=0.04). No correlation was seen with a change in bowel wall thickness or BWH postinduction.

CONCLUSIONS

Our pilot study suggests that SBUS is a feasible, noninvasive tool to measure early treatment response to IFX. BWH, not bowel wall thickness, is the first parameter to change. Larger longitudinal studies are warranted to validate the utility of SBUS as part of a disease monitoring strategy.

Accuracy of Ultrasound for Evaluation of Colorectal Segments in Patients With Inflammatory Bowel Diseases: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The accuracy of ultrasound for evaluation of individual colorectal segments in patients with inflammatory bowel diseases (IBD) has not been evaluated in a systematic review. We evaluated the diagnostic accuracy of ultrasound in different colorectal segments of patients with IBD.

METHODS

We searched publication databases from inception through March 2019 for studies that assessed the accuracy of ultrasound in detection of inflammation in right, transverse, and left colon and in rectum in patients with IBD, using findings from colonoscopy as the reference standard. Subgroup analyses were performed including IBD type, patient age, body mass index, and study design. The risk of bias was assessed with the Quality Assessment of Diagnostic Accuracy Studies-2 tool.

RESULTS

Nineteen studies (1101 patients) were included in the qualitative synthesis. After we assessed the risk of bias, 7 studies (comprising 84 patients with Crohn's disease and 420 patients with ulcerative colitis) were included in the meta-analysis. Bowel wall thickness ≥ 3 mm identified colorectal segments with inflammation with 86.4% pooled sensitivity (95% CI, 76.1%-92.7%) and 88.3% pooled specificity (95% CI, 58.1%-97.6%). In rectum only, bowel wall thickness ≥ 3 mm identified inflammation with 74.5% sensitivity (95% CI, 53.0%-88.3%) and 69.5% specificity (95% CI, 33.6%-91.1%). Diagnostic accuracy was comparable among subgroups. Increased bowel wall flow and loss of stratification had higher true-positive odds ratios.

CONCLUSIONS

Based on meta-analysis of patient-level data, ultrasound has higher diagnostic accuracy for detecting inflammation in colon than rectum in patients with IBD. Studies are needed to increase the accuracy of ultrasound detection of inflammation in rectum.

Relevance of monitoring transmural disease activity in patients with Crohn's disease: current status and future perspectives

Treatment targets of inflammatory bowel diseases (IBD), ulcerative colitis (UC) and Crohn's disease (CD) have evolved over the last decade. Goals of therapy consisting of symptom control and steroid sparing have shifted to control of disease activity with endoscopic remission being an important endpoint. Unfortunately, this requires ileocolonoscopy, an invasive procedure. Biomarkers [C-reactive protein (CRP) and fecal calprotectin (FCP)] have emerged as surrogates for endoscopic remission and disease activity, but also have limitations. Despite this evolution, we must not lose sight that CD involves transmural inflammation, not fully appreciated with ileocolonoscopy. Therefore, transmural assessment of disease activity by cross-sectional imaging, in particular with magnetic resonance enterography (MRE) and intestinal ultrasonography (IUS), is vital to fully understand disease control. Bowel-wall thickness (BWT) is the cornerstone in assessment of transmural inflammation and BWT normalization, with or without bloodflow normalization, the key element demonstrating resolution of transmural inflammation, namely transmural healing (TH) or transmural remission (TR). In small studies, achievement of TR has been associated with improved long-term clinical outcomes, including reduced hospitalization, surgery, escalation of treatment, and a decrease in clinical relapse over endoscopic remission alone. This review will focus on the existing literature investigating the concept of TR or residual transmural disease and its relation to other existing treatment targets. Current data suggest that TR may be the next logical step in the evolution of treatment targets.

Point-of-Care Ultrasound in Inflammatory Bowel Disease

Inflammatory bowel diseases [IBD], including Crohn's disease [CD] and ulcerative colitis [UC], are chronic, relapsing and destructive inflammatory disorders of the gastrointestinal tract which can lead to organ damage and impair quality of life. A 'treat-to-target' strategy based on activity and severity of disease and response to treatment with close monitoring of intestinal inflammation is recommended. Ileocolonoscopy [CS] is considered the first-line procedure for the assessment of IBD, and magnetic resonance enterography [MRE] is the current standard for assessing the small bowel and complications in CD, and has been proposed as an alternative procedure to CS in the evaluation of both ileo-colonic CD and UC. As that both CS and MRE are invasive and expensive procedures and unappealing to patients, they are unfeasible as frequent and repetitive tools for the monitoring of disease activity. Bowel ultrasound [US] represents a well-tolerated, non-invasive and cost-effective modality to manage IBD patients in clinical practice. Compared to CS and MRE, bowel US has been shown to have the same level of accuracy in assessing and monitoring disease activity and severity of both CD and UC. It can be performed at the point-of-care and therefore allow for real-time clinical decision-making. Point-of-care ultrasound [POCUS] is suggested as the stethoscope of the future and is gaining interest and diffusion in the medical field because it can be used for the bedside examination of patients. The aim of this review is to discuss point-of-care bowel ultrasound [POCBUS] in the management of patients with IBD.

Inflammation and fibrosis in Crohn's disease: location-matched histological correlation of small bowel ultrasound features

PURPOSE

To evaluate the utility of mural and extramural sonographic features of Crohn's Disease as potential imaging biomarkers of inflammation and fibrosis against whole-mount histological sections.

METHODS

Twelve Crohn's disease patients (Mean age 35(25-69), 7 males) underwent small bowel ultrasound prior to small bowel resection. Two radiologists in consensus graded multiple parameters including mural, mucosal and submucosal thickness, submucosal/mesenteric echogenicity and clarity and mural Doppler signal in 50 selected bowel cross-sections. Matching with histological sampling sites was facilitated via scanning of the resected specimen. A histopathologist scored acute and chronic inflammation, and fibrosis (using histological scoring systems) following analysis of whole mount block sections. The association between sonographic observations and histopathological scores was examined via univariable and multivariable analysis.

RESULTS

In univariate analyses, bowel wall thickness (regression co-efficient and 95% CI 0.8 (0.3, 1.3) p = 0.001), mesenteric fat echogenicity (8.7(3.0, 14.5) p = 0.005), submucosal layer thickness (7.4(1.2, 13.5) p = 0.02), submucosal layer clarity (4.4(0.6, 8.2) p = 0.02) and mucosal layer thickness (4.6(1.8, 7.4) p = 0.001) were all significantly associated with acute inflammation. Mesenteric fat echogenicity (674(8.67, 52404) p = 0.009), submucosal layer thickness (79.9(2.16, 2951) p = 0.02) and mucosal layer thickness (13.6(1.54, 121) p = 0.02) were significantly associated with chronic inflammation. Submucosal layer echogenicity (p = 0.03), clarity (25.0(1.76, 356) p = 0.02) and mucosal layer thickness (53.8(3.19, 908) p = 0.006) were significantly associated with fibrosis. In multivariate analyses, wall and mucosal thickness remained significantly associated with acute inflammation (p = 0.02), mesenteric fat echogenicity with chronic inflammation (p = 0.009) and mucosal thickness (p = 0.006) with fibrosis.

CONCLUSION

Multiple sonographic parameters are associated with histological phenotypes in Crohn's disease although there is overlap between ultrasonic stigmata of acute inflammation, chronic inflammation and fibrosis.

Ultrasound findings of Crohn's disease: correlation with MR enterography

Crohn's disease is a chronic inflammatory bowel disease characterized by periods of relative inactivity alternating with acute flare-ups. Imaging techniques play a fundamental role in the diagnosis and follow-up of Crohn's disease, providing information on the extent of disease, disease activity, and the presence of extramural complications. Because of the frequent re-evaluation required by the relapsing nature of Crohn's disease and the relative young age at which most patients are diagnosed, techniques that use ionizing radiation are best avoided in monitoring this population. Thus, magnetic resonance enterography (MRE) and ultrasonography (US) are the preferable techniques. Various studies have demonstrated that US is accurate in assessing the gut. Despite some clear advantages over MRE, US has long been underused in the evaluation of intestinal disease. This review presents an overview of the main imaging findings in Crohn's disease, correlating representative US images with MRE and surgical pathology specimens. We conclude that US reliably depicts both bowel-related and mesenteric features of Crohn's disease and US findings correlate strongly with MRE findings.

Recommendations of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU) on the use of abdominal ultrasound in inflammatory bowel disease

Ultrasound has an excellent diagnostic performance when Crohn's disease is suspected, when performing an activity assessment, or determining the extension and location of Crohn's disease, very similar to other examinations such as MRI or CT. It has a good correlation with endoscopic lesions and allows the detection of complications such as strictures, fistulas or abscesses. It complements colonoscopy in the diagnosis and, given its tolerance, cost and immediacy, it can be considered as a good tool for disease monitoring. In ulcerative colitis, its role is less relevant, being limited to assessing the extent and activity when it is not possible with other diagnostic techniques or if there are doubts with these. Despite its advantages, its use in inflammatory bowel disease (IBD) is not widespread in Spain. For this reason, this document reviews the advantages and disadvantages of the technique to promote knowledge about it and implementation of it in IBD Units.

Treatment of abdominal fistulas in Crohn's disease and monitoring with abdominal ultrasonography

OBJECTIVE

to assess the usefulness of medical treatment to achieve closure of internal fistulas detected on abdominal ultrasound in a series of patients with fistulizing Crohn's disease.

MATERIAL AND METHODS

a retrospective analysis was performed of the medical records of patients with Crohn's disease with a fistula detected on abdominal ultrasound from 2010 to 2018. The study included patients who received medical treatment after the diagnosis of this complication and underwent ultrasonographic monitoring of the therapeutic response. The factors associated with the response to medical treatment or the need for surgery were investigated.

RESULTS

forty-six patients were included in the study. Enteromesenteric (69.6 %) was the most common type of fistula and associated abscesses were found in 14 (30.4 %) patients. Fistulas were classified as complex in 20 patients. Treatment with immunosuppressants was started in 14 (30.4 %) cases and a biologic drug was added in 18 (39.1 %) patients. Complete closure of the abdominal fistula was observed with ultrasonography in 24 (52.2 %) of the 46 patients. The only factor related to fistula closure was the type of fistula and was more likely to occur in patients with an enteromesenteric fistula. Thirteen (28 %) of the 46 patients needed a surgical resection. The only factor with a significant correlation with a lower need for surgery was fistula closure after treatment (8.3 % vs 50 %, p = 0.002).

CONCLUSION

medical treatment achieves internal fistula closure in more than half of cases and almost a third require surgical treatment. Abdominal ultrasound can detect abdominal fistulas at an earlier stage and allow prompt treatment changes.

Usefulness of intestinal ultrasound in inflammatory bowel disease

Imaging techniques play a fundamental role in the initial diagnosis and follow-up of inflammatory bowel disease. Intestinal ultrasound has high sensitivity and specificity in patients with suspected Crohn's disease and in the detection of inflammatory activity. This technique enables the early diagnosis of intra-abdominal complications such as stenosis, fistulas, and abscesses. It has also proven useful in monitoring the response to treatment and in detecting postsurgical recurrence. Technical improvements in ultrasound scanners, technological advances such as ultrasound contrast agents and elastography, and above all increased experience have increased the role of ultrasound in the evaluation of the gastrointestinal tract. The features that make ultrasound especially attractive include its wide availability, its noninvasiveness and lack of ionizing radiation, its low cost, and its good reproducibility, which is important because it is easy to repeat the study and the study is well tolerated during follow-up. This review summarizes the role of intestinal ultrasound in the detection and follow-up of inflammatory bowel disease.

Optimizing biologic therapy in IBD: how essential is therapeutic drug monitoring?

Proposed treatment targets for the management of inflammatory bowel disease (IBD) have moved beyond symptomatic improvement towards more objective end points, such as healing of the intestinal mucosa. This treat-to-target approach has been associated with improved disease outcomes such as diminished bowel damage, surgery and hospitalizations. Many patients with IBD require biologic therapy to achieve and maintain clinical and endoscopic remission, and antitumour necrosis factor antibodies remain the first-line biologic therapy in most areas of the world. Unfortunately, up to one-third of patients receiving this treatment are primary non-responders, and some patients that show an initial response can also lose response over time. Therapeutic drug monitoring (TDM) has been suggested as a useful tool to manage patients on antitumour necrosis factor treatment, including monitoring for dose escalation, de-escalation or to switch treatment. In this Perspective, we aim to summarize evidence and guidelines related to TDM in IBD management and also discuss potential strategies to optimize biologic treatment where TDM is not available.

The Medical Management of Paediatric Crohn's Disease: an ECCO-ESPGHAN Guideline Update

OBJECTIVE

We aimed to provide an evidence-supported update of the ECCO-ESPGHAN guideline on the medical management of paediatric Crohn's disease [CD].

METHODS

We formed 10 working groups and formulated 17 PICO-structured clinical questions [Patients, Intervention, Comparator, and Outcome]. A systematic literature search from January 1, 1991 to March 19, 2019 was conducted by a medical librarian using MEDLINE, EMBASE, and Cochrane Central databases. A shortlist of 30 provisional statements were further refined during a consensus meeting in Barcelona in October 2019 and subjected to a vote. In total 22 statements reached ≥ 80% agreement and were retained.

RESULTS

We established that it was key to identify patients at high risk of a complicated disease course at the earliest opportunity, to reduce bowel damage. Patients with perianal disease, stricturing or penetrating behaviour, or severe growth retardation should be considered for up-front anti-tumour necrosis factor [TNF] agents in combination with an immunomodulator. Therapeutic drug monitoring to guide treatment changes is recommended over empirically escalating anti-TNF dose or switching therapies. Patients with low-risk luminal CD should be induced with exclusive enteral nutrition [EEN], or with corticosteroids when EEN is not an option, and require immunomodulator-based maintenance therapy. Favourable outcomes rely on close monitoring of treatment response, with timely adjustments in therapy when treatment targets are not met. Serial faecal calprotectin measurements or small bowel imaging [ultrasound or magnetic resonance enterography] are more reliable markers of treatment response than clinical scores alone.

CONCLUSIONS

We present state-of-the-art guidance on the medical treatment and long-term management of children and adolescents with CD.

Targeting the gut layers in Crohn's disease: mucosal or transmural healing?

INTRODUCTION

Although the landmark of Crohn's Disease (CD) is the transmural inflammation, mucosal healing (MH), which is assessed by colonoscopy, is currently the gold standard of CD management. Transmural healing (TH) is a new concept evaluated by cross-sectional imaging (CSI) techniques, such as bowel ultrasound (US), computed tomography enterography (CTE), and magnetic resonance enterography (MRE). Little is known about the clinical significance of persisting mural disease and the predictive value of complete TH.

AREAS COVERED

The authors reviewed the available literature on TH and its meaning as predictor of long-term outcomes in CD, to explore if TH may be a better target compared to MH in CD patients, in terms of disease outcome, such as medication changes, hospitalization, or surgery.

EXPERT OPINION

Some evidence suggests that achieving TH has a predictive value in CD management and correlates with better disease outcome than MH, although existing studies are few and with limitations. A definitive definition of TH is not yet established and the frequency or the preferred modality of TH evaluation remains unclear. Implementing TH in treat-to-target approach may enable stricter disease monitoring with noninvasive methods and finally change the disease course, preventing irreversible bowel damage.

Response Assessed by Ultrasonography as Target of Biological Treatment for Crohn's Disease

BACKGROUND & AIMS

Mucosal healing, determined by ileocolonoscopy, is a goal for treatment of Crohn's disease (CD), but this is an invasive assessment procedure. We investigated whether response to tumor necrosis factor (TNF) antagonists, determined by small-intestine contrast ultrasonography, associates with long-term outcomes.

METHODS

We performed observational study of 80 patients with CD treated with anti-TNF agents for at least 1 year who underwent serial small intestine contrast ultrasonography (SICUS) at the University of Rome, in Italy. SICUS was used to evaluate disease site (based on bowel wall thickness), extent of lesions, and presence of complications. Inclusion criteria required pre-therapy SICUS with follow-up SICUS after 18 months. At second SICUS, patients were assigned to categories of complete or partial responder or non-responder. CD-related outcomes (corticosteroid need, hospitalization, and surgery) were assessed at 1 year from the second SICUS, using multivariate models, and were analyzed after long term follow up (5 years) using Kaplan-Meier survival analysis.

RESULTS

Based on SICUS, after a median of 18 months, 36 patients (51%) were complete responders, 30 were partial responders (34%), and 13 were non-responders (15%). At 1 year from the second SICUS, no patients with a complete response, based on ultrasonography, underwent surgery, in comparison to partial responders (P = .0003) or non-responders (P = .001). Complete responders used smaller amounts of corticosteroids than partial responders (P = .0001) or non-responders (P < .0001). Complete responders required fewer hospitalizations than non-responders (P = .001). Kaplan-Meier survival analysis of long-term follow up data demonstrated a lower cumulative probability of need for surgery, hospitalization, and need for steroids among SICUS-categorized complete responders (P < .0001, P = .003 and P = .0001 respectively) than SICUS-categorized non-responders.

CONCLUSIONS

In patients with CD, response to anti-TNF agents, determined by SICUS, is associated with better long-term outcomes than partial or no response. Ultrasonographic assessment therefore provides a relatively non-invasive method for monitoring response to treatment in patients with CD.

Use of Cross-Sectional Imaging for Tight Monitoring of Inflammatory Bowel Diseases

A treat-to-target strategy with close monitoring of intestinal inflammation is recommended in inflammatory bowel disease (IBD). Ileocolonoscopy remains the gold standard for assessing disease activity in IBD but is a relatively invasive procedure and is impossible to repeat in the context of tight monitoring strategies. In addition to biomarkers, cross-sectional imaging increasingly is used in these patients. Computed tomography is limited by the use of radiation, while the use of magnetic resonance enterography (MRE) is limited by its cost and access. There is growing interest in bowel ultrasound that represents a cost-effective, noninvasive, and well-tolerated modality in clinical practice, but it is operator dependent. Compared with ileocolonoscopy and MRE, bowel US has been shown to have the same level of accuracy in assessing and monitoring disease activity for both CD and UC and thus can be considered a point-of-care test. Diffusion-weighted imaging (DWI) is a MR imaging technique that increasingly is used in both IBD and non-IBD conditions and has been shown to be a valuable and accurate tool for assessing and monitoring IBD activity. Compared with conventional MRE, DWI is quicker, less time consuming, may not require intravenous contrast agent, fasting, bowel cleansing, oral preparation, or rectal preparation. This review discusses the role of these cross-sectional imaging techniques for the management of patients with IBD. In the near future, the value of DWI and ultrasound in assessing IBD will require further investigation in the era of transmural healing in CD and complete mucosal healing, including histologic remission, in ulcerative colitis.

Objective evaluation for treat to target in Crohn's disease

BACKGROUND

Crohn's disease (CD) is a chronic and destructive bowel disease; continued disease activity can lead to penetrating complications. With the recent advent of effective medications, the importance of using a treat-to-target approach to guide therapy is becoming important.

METHODS

In this review, we reviewed the previous evidence for evaluating CD lesions.

RESULTS

We describe ileocolonoscopy's role in assessing disease activity, as well as recent progress in modalities, such as balloon-assisted endoscopy, capsule endoscopy, magnetic resonance enterography, computed tomography enterography, and ultrasonography. Advances in modalities have changed CD assessment, with small-bowel involvement becoming more important.

CONCLUSIONS

Proper optimization is necessary in clinical practice.

Impact of intestinal ultrasound on the management of patients with inflammatory bowel disease: how to apply scientific evidence to clinical practice

Technological improvements and growing sonographers' expertise boost the role of intestinal ultrasound (IUS) in assessing patients with inflammatory bowel diseases (IBD). Non-invasiveness, low cost and good reproducibility make IUS attractive. Leveraging on the Authors' long-term field experience, this review focuses on the IUS role in IBD patients' clinical management. For detecting IBD, particularly Crohn's disease, the IUS parameters - above all the evidence of a thickened bowel wall (BWT) - show very good diagnostic accuracy similar to that of MRI or CT scan. The standard IUS parameters are not accurate enough to detect inflammatory activity, but intravenous contrast-enhanced US (CEUS) is highly accurate in ruling active inflammation out. However, its routinely use remains limited in clinical practice and its parameters need standardization. IUS is accurate in detecting IBD main complications: in particular, fistulae and abscesses. As to stenosis the recent introduction of IUS-based elastographic techniques allows to differentiate prevalently inflammatory from highly fibrotic strictures. IUS proves valid also for monitoring IBD patients. In particular, the evidence of transmural healing, defined as BWT normalization, has got an important prognostic meaning, as associated with better long-term clinical outcomes. Post-surgery CD recurrence can be suggested by early IUS assessment.

Point-of-care gastrointestinal ultrasound in inflammatory bowel disease: An accurate alternative for disease monitoring

Background and Aim

Point‐of‐care ultrasound (POCUS) is a noninvasive alternative to ileocolonoscopy for monitoring disease activity in inflammatory bowel disease (IBD) but is underutilized in practice. Accuracy data are needed to engender clinician confidence in POCUS and increase uptake. The aim of this study was to evaluate the accuracy of POCUS compared to ileocolonoscopy in detecting active disease and extent in patients with IBD.

Methods

A prospective, blinded study was performed at a single tertiary center in South Australia between May 2017 and May 2018. Consecutive patients with a formal diagnosis of IBD who underwent both POCUS and ileocolonoscopy within 30 days of one another, performed to evaluate IBD disease activity, were eligible for participation. The accuracy of POCUS compared to ileocolonoscopy was assessed using sensitivity, specificity, and Cohen's kappa coefficient analyses.

Results

A total of 74 patients were included in the final analysis, 35 (47%) of whom had Crohn's disease and 39 (53%) ulcerative colitis; 37 subjects (50%) underwent a POCUS and ileocolonoscopy on the same day. POCUS demonstrated 91% sensitivity and 83% specificity for detecting endoscopically active IBD, correlating with a positive predictive value (PPV) of 89%, a negative predictive value (NPV) of 86%, and a kappa coefficient of 0.74 (88%). POCUS defined disease extent with 87% sensitivity and 81% specificity, correlating with a PPV of 85% and NPV of 83% and a kappa coefficient of 0.70 (85%).

Conclusion

POCUS is accurate in defining disease activity and extent in IBD compared to ileocolonoscopy. POCUS represents an appealing, noninvasive alternative to ileocolonoscopy for monitoring disease activity in IBD.

Gastrointestinal ultrasound in inflammatory bowel disease care: Patient perceptions and impact on disease-related knowledge

Background and Aim

Objective monitoring of disease activity is integral to therapeutic decision-making in inflammatory bowel disease (IBD). Data are sparse on patients' perspectives of tools used to monitor disease activity in IBD. To evaluate patients' perspectives of gastrointestinal ultrasound (GIUS) performed during routine IBD clinical care, along with its impact on IBD-specific knowledge.

Methods

Patients with a formal diagnosis of IBD who underwent GIUS at two tertiary IBD services between March 2017 and January 2019 participated in this prospective study. Participants completed a questionnaire measuring the acceptability, tolerability, and usefulness of GIUS using a visual analogue scale (VAS) from 0 (disagree) to 10 (strongly agree). Comparative acceptability of IBD monitoring tools and the impact of GIUS on IBD-specific knowledge was measured.

Results

A total of 121 participants completed the questionnaire, with a mean age of 42 years (range 17-78), 54 (45%) males, and 79 (65%) Crohn's disease patients. In the overall population, GIUS was scored as highly acceptable for monitoring IBD (mean 9.20 ± 1.37) compared to colonoscopy (7.94 ± 2.30), stool sampling (8.17 ± 1.96), blood sampling (8.87 ± 1.62), and imaging (8.67 ± 1.60); P < 0.01 for each comparison. GIUS caused little patient discomfort (1.88 ± 1.83), and 98 (81%) participants ranked GIUS as their preferred IBD monitoring tool. GIUS also improved patients' overall IBD-specific knowledge (VAS IBD-specific knowledge 7.96 ± 1.92), including their understanding of the need for medical therapy and disease extent.

Conclusion

GIUS is a highly acceptable and well-tolerated tool for monitoring disease activity in IBD patients. GIUS is preferred by patients and enhances IBD-specific knowledge.

Clinical Impact of Sonographic Transmural Healing After Anti-TNF Antibody Treatment in Patients with Crohn's Disease

AIM

To assess the clinical benefits of transmural healing (TH) shown on intestinal ultrasound (IUS) after treatment with tumor necrosis factor-alpha antibodies (anti-TNF) in patients with Crohn's disease.

MATERIALS AND METHODS

This prospective study included consecutively 36 patients who underwent IUS in the week prior to start anti-TNF treatment, at 12 weeks, and 1 year after starting treatment. The clinical response to treatment was assessed using the Crohn's disease activity index and C-reactive protein (CRP) values. TH was defined as the normalization of bowel wall thickness on IUS. Treated patients were considered to have a good outcome if none of the following situations presented: need to reintroduce corticosteroids or intensify maintenance therapy and/or need for surgery.

RESULTS

After the induction regimen, 29 patients (80.6%) achieved clinical remission, and serum CRP values returned to normal in 20 patients (55.6%). In the IUS at 12 weeks, treatment induced a statistically significant reduction in the wall thickness (p < 0.001) and color Doppler grade (p < 0.001), as well as resolution of complications in 66.7% of patients (p < 0.03). IUS after 1 year of biological therapy showed TH in 14/33 patients (42.4%). During the follow-up (median 48.5 months), 23 of the 33 (69.7%) patients in remission or response after induction therapy presented a good outcome. Sonographic TH was significantly related with better outcomes, with only 1/14 patients having a poor outcome compared to 9/19 without TH (OR 11.7, 95% CI 1.2-108.2 p = 0.01, Chi-squared test).

CONCLUSION

Patients who achieve TH on IUS with biological treatment have better clinical outcomes.

Diagnostic pathways in Crohn's disease

The management of Crohn's disease (CD) is shifting from a stepwise, incremental approach based on symptom control to more aggressive early combined immunosuppression in an attempt to induce remission more rapidly and avoid long-term bowel damage. Accurately defining disease activity is a major challenge, as there is often a disconnect between symptomatology and underlying disease status. The role of imaging in CD has evolved such that it now plays a central role establishing the initial diagnosis, characterising disease phenotype, activity assessment, disease surveillance, and assessing response to therapy. Furthermore, the "treat-to-target" approach is being investigated in CD, with resolution of transmural inflammation on cross-sectional imaging being the treatment goal. In this review, we summarise the principal imaging techniques available to the radiologist, the key findings, and provide some guidance on the preferred imaging option in the diagnostic pathway. We consider the relative merits and drawbacks of each imaging technique before offering a brief discussion of some current developments and research avenues in CD imaging. We discuss how imaging may be useful in a "treat-to-target" approach. Finally, we highlight some practical considerations around service configuration and delivery to optimise imaging in CD in an accurate, cost-effective manner.

Intravenous Contrast-Enhanced Ultrasound for Assessing and Grading Postoperative Recurrence of Crohn's Disease

PURPOSE

The aim was to investigate the contribution of contrast-enhanced ultrasound (CEUS) to improve the results of US in the evaluation of recurrence in postsurgical Crohn's disease (CD) and establish its role in the assessment of the severity.

METHODS

Anastomotic site was assessed in 108 postsurgical CD patients with B-mode, color Doppler and CEUS. Bowel wall thickness (WT), transmural complications or stenosis, color Doppler grade, and bowel wall contrast enhancement (BWCE)-using time-intensity curves-were correlated with endoscopic Rutgeerts score. A receiver operating characteristic (ROC) curve was built to establish the best cutoff to predict recurrence and the severity. A US scoring system was elaborated in order to determine the grade of recurrence.

RESULTS

Ileocolonoscopy detected recurrence in 90 (83.3%) subjects and severe recurrence in 62. WT ≥ 3 mm had an accuracy of 90.7% in the detection of endoscopic recurrence. The combination of parameters-WT ≥ 3 mm and BWCE (≥ 46%)-demonstrated similar accuracy (90.7%). A WT ≥ 5 mm showed the best specificity (100%) for the diagnosis of recurrence and a WT ≥ 6 mm the best specificity (95.7%) for the detection of severe recurrence. The combination of sonographic parameters-WT ≥ 6 mm or WT between 5 and 6 mm with BWCE ≥ 70%, or complications-obtained the best results grading the recurrence (sensitivity, specificity, and accuracy of 90.3%, 87%, and 88.9%, respectively).

CONCLUSIONS

US shows high sensitivity and specificity for the diagnosis of postsurgical recurrence. When combined with CEUS, it can improve the detection of severe recurrence.

The Role of Intravenous Contrast Agent in the Sonographic Assessment of Crohn's Disease Activity: Is Contrast Agent Injection Necessary?

BACKGROUND AND AIMS

Contrast-enhanced ultrasound [CEUS] is reported to be superior to wall thickness or colour Doppler imaging [CDI] in predicting disease activity using endoscopy as the reference standard. Our aims were to determine in patients with Crohn's disease [CD] whether the evaluation of wall thickness or CDI before CEUS examination could help to decide when the injection of contrast agent is justified as a means for detecting disease activity as determined at endoscopy, without reducing the accuracy of ultrasound.

METHODS

In total, 180 patients with CD underwent both colonoscopy and ultrasound, including mural thickness, CDI and CEUS evaluation, prospectively as part of clinical care. A receiver operating characteristic curve was constructed to determine the area under the curve and the best cutoff of wall thickness and ultrasound enhancement value to discriminate between endoscopically active and inactive disease. Several analyses were carried out to determine which parameter or combination of parameters best detected endoscopic activity.

RESULTS

Comparative evaluation of the different analysis showed that wall thickness alone classified 76.6% of patients correctly, CDI alone 72.7%, and thickness plus CDI 72.2%. The use of CEUS significantly improved the diagnosis of active disease: CEUS alone correctly classified 164 of 180 patients [91.1%], combined analysis of CDI and CEUS 165 of 180 [91.7%], and combined analysis of thickness, CDI and CEUS 164 of 180 [91.1%], without significant differences. Patients with CDI grade 2 or 3 showed a predictive positive value of 97% to detect disease activity, similar to CEUS [100%].

CONCLUSION

CEUS is the most reliable ultrasound criterion for endoscopic disease activity. However, the use of a contrast agent is probably not justified to assess disease activity for patients with CDI grade 2/3.

Abdominal ultrasonography with color Doppler analysis in the assessment of ileal Crohn's disease: comparison with magnetic resonance enterography

Background/Aims

Consistently defining disease activity remains a critical challenge in the follow-up of patients with Crohn’s disease (CD). We investigated the potential applicability of abdominal ultrasonography with color Doppler (USCD) analysis for the detection of morphological alterations and inflammatory activity in CD.

Methods

Forty-three patients with CD ileitis/ileocolitis were evaluated using USCD analysis with measurements obtained on the terminal ileum and right colon. Sonographic parameters included wall thickening, stricture, hyperemia, presence of intra-abdominal mass, and fistulas. Patients were evaluated for the clinical activity (Harvey-Bradshaw Index [HBI]), fecal calprotectin (FC) and C-reactive protein (CRP). The USCD performance was assessed using magnetic resonance enterography (MRE) as a criterion standard.

Results

Most measurements obtained with USCD matched the data generated with MRE; however, the agreement improved in clinically active patients where sensitivity, positive predictive value, and accuracy were >80%, considering wall thickening and hyperemia. Complications such as intestinal wall thickening, stricture formation, and hyperemia, were detected in the USCD analysis with moderate agreement with MRE. The best agreement with the USCD analysis was obtained in regard to FC, where the sensitivity, positive predictive value, and accuracy were >70%. The overall performance of USCD was superior to that of HBI, FC and CRP levels, particularly when considering thickening, stricture, and hyperemia parameters.

Conclusions

USCD represents a practical noninvasive and low-cost tool for evaluating patients with ileal or ileocolonic disease, particularly in clinically active CD. Therefore, USCD might become a useful asset in the follow-up of patients with CD.