Gastrointestinal ultrasound in inflammatory bowel disease: an underused resource with potential paradigm-changing application

Catalase catalyzed tannic acid-Fe3+ network coating: A theranostic strategy for intestinal barrier restoration

Epithelial barrier impairment of intestinal inflammation leads to the leakage of bacteria, antigens and consequent persistent immune imbalance. Restoring the barrier function holds promise for management of intestinal inflammation, while the theragnostic strategies are limited. In this study, we developed a novel coating by catalase (CAT)-catalyzed polymerization of tannic acid (TA) and combined chelation network with Fe3+. TA-Fe3+ coating was self-polymerized in situ along the small intestinal mucosa, demonstrating persistent adhesion properties and protective function. In enteritis models, sequential administration of TA-Fe3+ complex solution effectively restored the barrier function and alleviated the intestinal inflammation. Overexpressed CAT in inflammatory lesion is more favorable for the in situ targeting growth of TA-Fe3+ coating onto the defective barrier. Based on the high longitudinal relaxivity of Fe3+, the pathologically catalyzed coating facilitated the visualization of intestinal barrier impairment through MRI. In conclusion, the novel TA-Fe3+ delivery coating proposed an alternative approach to promote theranostic intervention for intestinal diseases.

Artificial intelligence and endo-histo-omics: new dimensions of precision endoscopy and histology in inflammatory bowel disease

Integrating artificial intelligence into inflammatory bowel disease (IBD) has the potential to revolutionise clinical practice and research. Artificial intelligence harnesses advanced algorithms to deliver accurate assessments of IBD endoscopy and histology, offering precise evaluations of disease activity, standardised scoring, and outcome prediction. Furthermore, artificial intelligence offers the potential for a holistic endo-histo-omics approach by interlacing and harmonising endoscopy, histology, and omics data towards precision medicine. The emerging applications of artificial intelligence could pave the way for personalised medicine in IBD, offering patient stratification for the most beneficial therapy with minimal risk. Although artificial intelligence holds promise, challenges remain, including data quality, standardisation, reproducibility, scarcity of randomised controlled trials, clinical implementation, ethical concerns, legal liability, and regulatory issues. The development of standardised guidelines and interdisciplinary collaboration, including policy makers and regulatory agencies, is crucial for addressing these challenges and advancing artificial intelligence in IBD clinical practice and trials.

Editorial: Leveraging existing mid-end ultrasound machine for point-of-care intestinal ultrasound in low-resource settings-Prospective, real-world impact on clinical decision making

This article is linked to Pal et al papers. To view these articles, visit https://https://doi.org/10.1111/apt.18155 and https://doi.org/10.1111/apt.18189

Intestinal ultrasound scan predicts corticosteroid failure and colectomy risk in patients with ulcerative colitis

OBJECTIVE

Intestinal ultrasound (IUS) is an emerging modality for assessing disease activity, extent, and treatment response in ulcerative colitis. This study aimed to evaluate the potential of IUS in predicting severe flares, the need for rescue therapy (corticosteroid failure), and colectomy in patients with ulcerative colitis.

METHODS

We conducted a retrospective review of medical records, collecting clinical and IUS data. The Milan Ultrasound Criteria (MUC) score was used to assess ulcerative colitis severity. Group comparisons were performed to identify differences in MUC scores between mild-to-moderate and severe ulcerative colitis, between steroid responders and nonresponders, and between patients who underwent colectomy and those who did not. Receiver operating characteristic (ROC) analysis was used to predict outcomes in patients with ulcerative colitis.

RESULTS

This analysis included 102 patients with ulcerative colitis categorized as mild/moderate (60) or severe (42). MUC scores were significantly higher in the severe ulcerative colitis group compared with the mild/moderate group ( P  < 0.001). Analysis (using ROC) identified a cutoff MUC score of >8.54 to indicate severe ulcerative colitis with good sensitivity (64.29%) and excellent specificity (93.33%). Similarly, a cutoff of MUC > 10.54 showed promise in predicting corticosteroid failure, with acceptable sensitivity (50%) and high specificity (90.91%). Finally, a cutoff MUC score >12.5 demonstrated potential for predicting colectomy, exhibiting moderate sensitivity (55.56%) but excellent specificity (96.97%).

CONCLUSION

IUS may be useful for differentiating severe ulcerative colitis from mild-to-moderate disease, identifying early stage failure of corticosteroid therapy, and predicting the potential need for colectomy.

Substantial cost savings of ultrasound-based management over magnetic resonance imaging-based management in an inflammatory bowel disease service

BACKGROUND

Imaging is used to monitor disease activity in small bowel Crohn's disease (CD). Magnetic Resonance Enterography is often employed as a first modality in the United Kingdom for assessment and monitoring; however, waiting times, cost, patient burden and limited access are significant. It is as yet uncertain if small bowel intestinal ultrasound (IUS) may be a quicker, more acceptable, and cheaper alternative for monitoring patients with CD.

METHODS

A clinical service evaluation of imaging pathways was undertaken at a single NHS site in England, United Kingdom. Data were collected about patients who were referred and underwent an imaging analysis for their IBD. Only patients who underwent a therapy change were included in the analysis. Data were collected from care episodes between 01 January 2021-30 March 2022.

RESULTS

A combined total of 193 patient care episodes were reviewed, 107 from the IUS pathway and 86 from the MRE pathway. Estimated costs per patient in the IUS pathway was £78.86, and £375.35 per patient in the MRE pathway. The MRE pathway had an average time from referral to treatment initiation of 91 days (SD= ±61) with patients in the IUS pathway waiting an average of 46 days (SD= ±17).

CONCLUSIONS

Findings from this work indicate that IUS is a potential cost-saving option when compared to MRE when used in the management of CD. This is in addition to the cost difference of the radiological modalities. A large, multicentre, prospective study is needed to validate these initial findings.

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.

Clinical Application of Intestinal Ultrasound in Inflammatory Bowel Disease

PURPOSE OF REVIEW

Intestinal ultrasound (IUS) is a non-invasive, accurate, and well-tolerated tool that provides real-time assessment of inflammatory bowel disease (IBD) activity and is therefore an ideal monitoring tool. This review describes the evolving role of IUS in each phase of clinical management of IBD.

RECENT FINDINGS

Accumulating evidence has demonstrated that IUS is an excellent tool for the assessment of suspected IBD, with a very high negative predictive value. It accurately assesses disease activity, disease complications, and in the pre-treatment phase, provides a benchmark for subsequent follow-up. IUS can detect early therapeutic response and correlates well with other established monitoring modalities with arguably superior predictive capabilities and ability to assess a deeper degree of remission, transmural healing (TH). IUS has a crucial role in the management of IBD and has ushered in a new era of monitoring with more rapid evaluation and the opportunity for early optimization, deeper therapeutic targets, and improved outcomes.

Composite Assessment Using Intestinal Ultrasound and Calprotectin Is Accurate in Predicting Histological Activity in Ulcerative Colitis: A Cohort Study

BACKGROUND

Beyond endoscopic remission, histological remission in ulcerative colitis (UC) is predictive of clinical outcomes. Intestinal ultrasound (IUS) may offer a noninvasive surrogate marker for histological activity; however, there are limited data correlating validated ultrasound and histological indices.

AIM

Our aim was to determine the correlation of IUS activity in UC with a validated histological activity index.

METHODS

Twenty-nine prospective, paired, same-day IUS/endoscopy/histology/fecal calprotectin (FC) cases were included. Intestinal ultrasound activity was determined using the Milan Ultrasound Criteria, histological activity using the Nancy Histological Index, endoscopic activity using Mayo endoscopic subscore and Ulcerative Colitis Endoscopic Index of Severity, and clinical activity using the Simple Clinical Colitis Activity Score.

RESULTS

Histological activity demonstrated a significant linear association with overall IUS activity (coefficient 0.14; 95% CI, 0.03-0.25; P = .011). Intestinal ultrasound activity was also significantly associated with endoscopic activity (0.32; 95% CI, 0.14-0.49; P < 0.001), total Mayo score (0.31; 95% CI, 0.02-0.60; P = .036) but not FC (0.10; 95% CI, -0.01 to 0.21; P = .064) or clinical disease activity (0.04; 95% CI, -0.21 to 0.28; P = .768). A composite of IUS and FC showed the greatest association (1.31; 95% CI, 0.43-2.18; P = .003) and accurately predicted histological activity in 88% of cases (P = .007), with sensitivity of 88%, specificity 80%, positive predictive value 95%, and negative predictive value 57%.

CONCLUSIONS

Intestinal ultrasound is an accurate noninvasive marker of histological disease activity in UC, the accuracy of which is further enhanced when used in composite with FC. This can reduce the need for colonoscopy in routine care by supporting accurate point-of-care decision-making in patients with UC.

Comprehensive review and update of stricturing Crohn's disease

Up to 50% of patients with Crohn's disease develop a stricture within 10 years of diagnosis. Crohn's strictures can compose of inflammation, fibrosis or smooth muscle expansion and usually a combination of these. There have been numerous new developments in imaging modalities in determining the composition of Crohn's strictures. Magnetic resonance imaging remains the best upfront imaging modality to characterize Crohn's strictures. Gastrointestinal ultrasound (GIUS) has an increasing role in clinical practice, particularly for monitoring stricture response as a treat-to-target tool. Novel imaging techniques to differentiate between fibrosis and inflammatory strictures have been developed including contrast-enhanced GIUS, strain or shear wave elastography with GIUS and multiple new magnetic resonance imaging (MRI) protocols, including diffusion weighted, delayed contrast enhancement and magnetization transfer MR protocols. However, these techniques require further validation and standardization. Regarding therapeutics, anti-tumor necrosis agents with a treat-to-target strategy have the highest quality evidence in treating strictures and can lead to stricture regression in some cases. Endoscopic balloon dilatation remains a mainstay in the treatment algorithm of treating predominantly fibrostenotic Crohn's strictures, particularly those which are symptomatic, < 5 cm in length and not causing prestenotic dilatation. Endoscopic balloon dilatation has greater effectiveness in anastomotic strictures. Surgery remains an important treatment option in Crohn's strictures, with segmental resection and stricturoplasty having their own advantages and disadvantages. Kono-S anastomosis may be superior to conventional anastomosis for endoscopic recurrence; however, further high-quality studies are required to confirm this. Using risk stratification models such as the BACARDI risk model is important to guide management decisions between a medical and surgical approach. Early post-operative medical prophylaxis with an advanced therapy is an important consideration to prevent disease recurrence. This review expands on the above topics, highlights research gaps and provides a suggested investigation and management pathway in stricturing Crohn's disease.

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.

Wall Thickness Ratio-A New Magnetic Resonance Parameter-Is Associated With the Outcome of Biological Therapy in Patients With Ileal and Ileocolonic Crohn's Disease

GOALS

The present study was aimed at identifying a new magnetic resonance enterography (MRE) parameter assessing the clinical outcome of biological therapy in patients with active ileal/ileocolonic Crohn's disease (CD).

BACKGROUND

Transmural healing (TH) has been associated with improved outcomes in CD. However, some patients with clinical remission and inactive disease at endoscopy do not achieve TH.

MATERIALS AND METHODS

Ileal/ileocolonic CD patients scheduled for biological therapy were prospectively evaluated, at baseline (T0) and after 1 year of treatment (T1), with Harvey Bradshaw Index score, blood tests, ileocolonscopy, and MRE. Clinical activity was assessed after 2 years of treatment (T2). Wall thickness ratio (WTR) was calculated in the same affected ileal segment, as the ratio between the ileum wall thickness value at T1 and the ileum wall thickness value at T0.

RESULTS

A total of 103 patients were included. Mean WTR at T1 in nonresponders was significantly higher than in responders. At receiver operating characteristic analysis, WTR values were significantly associated to biological therapy responsiveness. A WTR cutoff value of 0.77 mm was identified to discriminate responders from nonresponders (sensitivity: 79%; specificity: 67%). In responders, the proportion of patients with a WTR<0.77 was significantly higher than the proportion of patients achieving TH at T1. Among patients achieving endoscopic remission, 11/29 (37.9%) presented TH, while 20/29 (68.9%) presented WTR<0.77 ( P : 0.035). At multivariate logistic regression analysis, WTR<0.77 was significantly associated to biological therapy response.

CONCLUSION

WTR index represents an easy-to-calculate MRE parameter and seems to be a promising tool for monitoring therapeutic response in CD patients during biological therapy.

The Disease Severity Index for Inflammatory Bowel Disease Is a Valid Instrument that Predicts Complicated Disease

BACKGROUND

The disease severity index (DSI) for inflammatory bowel disease (IBD) combines measures of disease phenotype, inflammatory activity, and patient-reported outcomes. We aimed to validate the DSI and assess its utility in predicting a complicated IBD course.

METHODS

A multicenter cohort of adults with IBD was recruited. Intraclass correlation coefficients (ICCs) and weighted Kappa assessed inter-rater reliability. Cronbach's alpha measured internal consistency of DSI items. Spearman's rank correlations compared the DSI with endoscopic indices, symptom indices, quality of life, and disability. A subgroup was followed for 24 months to assess for a complicated IBD course. Area under the receiver operating characteristics curve (AUROC) and multivariable logistic regression assessed the utility of the DSI in predicting disease progression.

RESULTS

Three hundred and sixty-nine participants were included (Crohn's disease [CD], n = 230; female, n = 194; mean age, 46 years [SD, 15]; median disease duration, 11 years [interquartile range, 5-21]), of which 171 (CD, n = 99; ulcerative colitis [UC], n = 72) were followed prospectively. The DSI showed inter-rater reliability for CD (ICC 0.93, n = 65) and UC (ICC 0.97, n = 33). The DSI items demonstrated inter-rater agreement (Kappa > 0.4) and internal consistency (CD, α > 0.59; UC, α > 0.75). The DSI was significantly associated with endoscopic activity (CDn=141, r = 0.65, P < .001; UCn=105, r = 0.80, P < .001), symptoms (CDn=159, r = 0.69, P < .001; UCn=132, r = 0.58, P < .001), quality of life (CDn=198, r = -0.59, P < .001; UCn=128, r = -0.68, P < .001), and disability (CDn=83, r = -0.67, P < .001; UCn=52, r = -0.74, P < .001). A DSI of 23 best predicted a complicated IBD course (AUROC = 0.82, P < .001) and was associated with this end point on multivariable analyses (aOR, 9.20; 95% confidence interval, 3.32-25.49).

CONCLUSIONS

The DSI reliably encapsulates factors contributing to disease severity and accurately prognosticates the longitudinal IBD course.

Leaving behind the Mucosa: Advances and Future Directions of Intestinal Ultrasound in Ulcerative Colitis

Inflammatory Bowel Diseases (IBD), mainly Ulcerative Colitis (UC) and Crohn's Disease (CD), are disorders characterized by chronic inflammation with severe morbidity and long-term disabling quality of life outcomes. UC mainly affects the mucosal and sub-mucosal layers of the colon, without embracing the peri-intestinal structures. Considering the predominant mucosal location of UC inflammation, the implementation of transmural evaluation by cross-sectional imaging techniques, mainly Intestinal Ultrasound (IUS), has been left behind for ages, especially if compared to CD. Nevertheless, studies analyzing intestinal ultrasound parameters accuracy in disease activity detection reported a good-to-optimal correlation of IUS markers with colonic inflammation, suggesting comparable feasibility of IUS monitoring in UC as in CD. The easy-to-use, costless and point-of-care available status of IUS is therefore crucial in order to improve the diagnostic process and, according to the recent literature, to monitor the response to treatment leading to speeding up decision making and therapy adjustments. Recent studies have demonstrated the correlation between transmural healing in UC with favorable outcomes even in the long term. An evidence gap still exists in the assessment of the rectum, with trans-perineal ultrasound (TPUS) a potential answer to reach a more precise evaluation of rectal inflammation. Eventually, IUS is also increasingly showing promises in emergent or post-surgical UC settings, considering various efforts put in line to demonstrate its feasibility in predicting response to salvage therapy for surgery avoidance and in studying inflammation relapse after procto-colectomy with ileo-pouch-anal anastomosis (IPAA) creation.

Assessing Active Bowel Inflammation in Crohn's Disease Using Intestinal Ultrasound: Correlation With Fecal Calprotectin

AIM

To analyze the correlation between intestinal ultrasound (IUS) and serum and fecal biomarkers, and the characteristics of small bowel disease, for the assessment of active bowel inflammation.

METHODS

Patients with Crohn's disease (CD) who underwent an initial IUS examination between July 2018 and November 2022 at our institution were included retrospectively. We divided small and large bowels into seven segments, and recorded the presence of active inflammation according to following criteria: bowel wall thickness ≥ mm with ≥1 of feature of active disease on IUS. The correlations between IUS-assessed activity and serum C-reactive protein (CRP, mg/dL) and fecal calprotectin (FC, μg/g) levels were analyzed.

RESULTS

A total of 127 patients were included (mean age: 32.42 ± 12.07, M:F = 90:37, median disease duration 6 years [0-35]). Of them, 78 showed active bowel inflammation (61.4%), with inflammation distal to the terminal ileum being the most common disease location (n = 61, 78.2%). FC and serum CRP levels were significantly correlated with the number of segments with active inflammation (rho = 0.58, 0.48), number of segments with complications (r = 0.35, 0.31), and US activity score (r = 0.62, 0.54). With FC cutoff values of 100 and 150 μg/g, the concordance rates for patients with active small bowel disease were 78.7% (26/33) and 72.7% (24/33), respectively, which were better than those for other disease locations.

CONCLUSIONS

Disease activity determined by IUS was significantly correlated with the biomarkers, with a better concordance rate in patients with active small bowel disease than in those with other disease locations with FC cut-off values of 100 and 150 μg/g.

Intestinal Ultrasound Combined with Blood Inflammatory Markers Is a More Efficient Tool in Evaluating Severity of Crohn's Disease: A Pilot Study

Background and Aims

Intestinal ultrasound (IUS) is considered a nonirradiating, noninvasive, well-tolerated, and valuable tool for objectively assessing Crohn's disease (CD) activity. However, there is no widely accepted intestinal ultrasound scoring system. This study is aimed at evaluating the efficacy of IUS key parameters, the International Bowel Ultrasound Activity Score (IBUS-SAS), and IBUS-SAS combined with blood inflammatory markers in assessing CD activity.

Methods

40 CD patients were reviewed in this retrospective study and were divided into the moderate-severe group (n = 25) and nonmoderate-severe group (n = 15) based on a simplified endoscopic score of Crohn's disease (SES-CD). Double-balloon enteroscopy/colonoscopy were reviewed by three gastroenterologists. A transabdominal ultrasound was performed by two ultrasound specialists. Blood inflammatory markers were measured from morning samples.

Results

In evaluating moderate to severe CD patients, (1) IBUS-SAS had a good predictive effect with an area-under-the-curve (AUC) of 0.855 (P < 0.001); (2) IUS key parameters (including BWT, CDS, BWS, and I-fat) yielded good predictive effects with AUC of 0.811, 0.731, 0.724, and 0.747, respectively (P < 0.001); (3) blood inflammatory markers (including ESR, CRP, PLR, MLR, and NLR) also had good predictive effects with AUC of 0.771, 0.837, 0.728, 0.743, and 0.775, respectively (P < 0.001); (4) IBUS-SAS combined with ESR and CRP exerted the best predictive effect with the highest AUC of 0.912 (95% CI: 0.823-1.000), and the sensitivity and specificity were 88.0% and 80.0%, respectively (P < 0.001).

Conclusion

IBUS-SAS combined with ESR and CRP is a more efficient tool than IBUS-SAS alone or inflammatory markers alone in evaluating CD patients with moderate to severe disease activity.

Correlation of Ultrasound Scores with Endoscopic Activity in Crohn's Disease: A Prospective Exploratory Study

BACKGROUND AND AIMS

Intestinal ultrasound [IUS] is widely accepted as a reliable tool to monitor Crohn's disease [CD]. Several IUS scores have been proposed, but none has been formally accepted by international organizations. Our aim here was to compare the available scores regarding their correlation with endoscopic activity.

METHODS

Consenting CD patients undergoing ileocolonoscopy at our Unit between September 2021 and February 2023 were included. Endoscopic activity was defined as SES-CD ≥ 3 or Rutgeerts score ≥ i2b for operated patients. IUS was performed within 6 weeks of endoscopy and scored with IBUS-SAS, BUSS, Simple-US and SUS-CD scores. All correlations were performed using Spearman's rank coefficient [rho = ρ]. Receiver operating characteristic [ROC] curves were compared with the Hanley and McNeil method.

RESULTS

Of 73 CD patients, 45 [61.6%] presented endoscopic activity, of whom 22 were severe [30.1%]. All IUS scores showed a significant positive correlation with endoscopy [p < 0.0001], with IBUS-SAS ranking the highest [ρ = 0.87]. Similarly, IBUS-SAS was the most highly correlated with clinical activity [ρ = 0.58]. ROC analysis of IBUS-SAS for any endoscopic activity showed the highest area under the curve (0.95 [95% confidence interval 0.87-0.99]), with sensitivity of 82.2% and specificity of 100% for a cut-off value of 25.2. IBUS-SAS was statistically superior to all the other scores in detecting severe endoscopic activity [SES-CD ≥ 9 or Rutgeerts i4].

CONCLUSIONS

All IUS scores provided solid correlation with endoscopy and clinical symptoms. IBUS-SAS outperformed the others due to a more granular description that might help in stratifying different levels of disease activity. Therefore, the use of IBUS-SAS in centres with well-founded expertise in IUS can be suggested.

Bedside Intestinal Ultrasound Performed in an Inflammatory Bowel Disease Urgent Assessment Clinic Improves Clinical Decision-Making and Resource Utilization

Background

Patients with inflammatory bowel disease (IBD) require accessible, timely, and noninvasive strategies to monitor disease. The aim was to assess the integration of intestinal ultrasound (IUS) on decision-making and endoscopy utilization in a standardized care pathway.

Methods

This prospective, multicenter, international, observational cohort study included patients seen within a centralized model for IBD care was conducted during the COVID pandemic. Patients were evaluated with IUS alone or in combination with an in-clinic, unsedated sigmoidoscopy. Demographic, clinical, laboratory, and imaging data, clinical decisions, and need for urgent endoscopy, hospitalization, and surgeries were recorded.

Results

Of the 158 patients included, the majority had an established diagnosis of Crohn's disease (n = 123, 78%), and 47% (n = 75) of patients were on biologic therapy. IUS identified active inflammation in 65% (n = 102) of patients, and strictures in 14% (n = 22). Fecal calprotectin levels correlated with inflammation detected on IUS (median of 50 μg/g [Q1-Q3: 26-107 μg/g] without inflammation and 270 μg/g [Q1-Q3: 61-556 μg/g] with inflammation; p = 0.0271). In the majority of patients, clinical assessment with IUS led to an acute change in IBD-specific medications (57%, n = 90) and avoided or delayed the need for urgent endoscopy (85%, n = 134). Four patients were referred for urgent surgical consultation.

Conclusions

Point-of-care IUS used in a flare clinic pathway is a useful strategy to improve effective IBD care delivery and to assist in therapeutic management decisions, in many cases avoiding the acute need for endoscopy.

The Role of Noninvasive Surrogates of Inflammation in Monitoring Pediatric Inflammatory Bowel Diseases: The Old and the New

Effectiveness of limited available therapies for pediatric inflammatory bowel disease has reached stagnation. Previous non-invasive monitoring strategies have relied upon cumbersome tools to evaluate clinical symptoms and biochemical markers that do not reflect endoscopic activity or respond quickly to treatments. Novel, patient-centric, and highly accurate, monitoring strategies with a focus on intestinal ultrasound for a direct, precise monitoring of activity to achieve disease modification are now possible. Ultimately, research on the optimal tight control monitoring strategies, individualized to each pediatric inflammatory bowel disease patient, are in development and offer a hope to potential therapeutic ceiling breakthrough on the horizon.

Challenges in the diagnosis and management of IBD: a sub-Saharan African perspective

With the exception of South Africa, inflammatory bowel disease (IBD) has long been considered uncommon in sub-Saharan Africa (SSA) with a dearth of peer-reviewed publications from the subcontinent. This most likely reflects underreporting as some cases may be missed due to the high burden of infectious diseases which may closely mimic IBD. In addition, many countries in SSA have limited endoscopic capacity, inadequate access to diagnostic imaging and a notable scarcity of histopathologists, radiologists and gastroenterologists. Beyond these obstacles, which significantly impact patient care, there are many other challenges in SSA, particularly the unavailability of key IBD therapies. In this review, we discuss barriers in diagnosing and managing IBD in SSA, as well as some of the initiatives currently in place to address these short comings.

External validation and comparison of simple ultrasound activity score and international bowel ultrasound segmental activity score for Crohn's disease

BACKGROUND

Intestinal ultrasound (IUS) is a non-invasive tool for monitoring Crohn's disease (CD) activity. Recently, sonographic activity scores, including the International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) and Simple Ultrasound Activity Score for CD (SUS-CD), were developed. This study aimed to assess their clinical application value.

METHODS

This retrospective study enrolled patients with CD from March 2021 to June 2022. The diagnostic performance of the ultrasound scores was evaluated using the simplified endoscopic score for CD (SES-CD). Correlations of ultrasound scores with SES-CD, CD activity index (CDAI), and inflammatory biomarkers were assessed. Inter-rater reliability was compared.

RESULTS

In total, 140 patients were included. The IBUS-SAS for evaluating disease activity had an area under the curve (AUC) of 0.895, sensitivity of 85.4%, and specificity of 82.4% for the cut-off value of 48.7. The SUS-CD revealed an AUC of 0.835, sensitivity of 92.7%, and specificity of 64.7% for the cut-off value of 2.5. The IBUS-SAS and SUS-CD were positively correlated with SES-CD (r = 0.511 and 0.534, respectively). The scores correlated significantly with the CDAI and inflammatory biomarkers (all p < 0.01). The IBUS-SAS was more strongly correlated with CDAI (r = 0.666 vs 0.486) and C-reactive protein (r = 0.645 vs 0.434) than the SUS-CD. The intraclass correlation coefficient (ICC) of the IBUS-SAS and SUS-CD between the two sonologists was excellent (ICC = 0.96 and 0.78, respectively).

CONCLUSION

Both the IBUS-SAS and SUS-CD can evaluate disease activity in CD and exhibited a significant correlation with activity indices and inflammatory biomarkers.

CLINICAL TRIAL REGISTRATION

ChiCTR2200055221.

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.

Intestinal ultrasound as a non-invasive tool to monitor inflammatory bowel disease activity and guide clinical decision making

Intestinal ultrasound (IUS) is a non-invasive, real-time, cross-sectional imaging tool that can be used at the point-of-care to assess disease activity in patients with Crohn’s disease or ulcerative colitis. IUS promotes quick and impactful treatment decisions that can modify disease progression and enhance patient compliance. This review will summarize the technical aspects of IUS, the evidence to support the use of IUS in disease activity monitoring, the comparison of IUS to current standard of care monitoring modalities such as colonoscopy and calprotectin, and the optimal positioning of IUS in a tight-control monitoring strategy.

Aptamer-Functionalized Microbubbles Targeted to P-selectin for Ultrasound Molecular Imaging of Murine Bowel Inflammation

PURPOSE

Our objectives were to develop a targeted microbubble with an anti-P-selectin aptamer and assess its ability to detect bowel inflammation in two murine models of acute colitis.

PROCEDURES

Lipid-shelled microbubbles were prepared using mechanical agitation. A rapid copper-free click chemistry approach (azide-DBCO) was used to conjugate the fluorescent anti-P-selectin aptamer (Fluor-P-Ap) to the microbubble surface. Bowel inflammation was chemically induced using 2,4,6-trinitrobenzenesulfonic acid (TNBS) in both Balb/C and interleukin-10-deficient (IL-10 KO) mice. Mouse bowels were imaged using non-linear contrast mode following an i.v. bolus of 1 × 10⁸ microbubbles. Each mouse received a bolus of aptamer-functionalized and non-targeted microbubbles. Mouse phenotypes and the presence of P-selectin were validated using histology and immunostaining, respectively.

RESULTS

Microbubble labelling of Fluor-P-Ap was complete after 20 min at 37 ̊C. We estimate approximately 300,000 Fluor-P-Ap per microbubble and confirmed fluorescence using confocal microscopy. There was a significant increase in ultrasound molecular imaging signal from both Balb/C (p = 0.003) and IL-10 KO (p = 0.02) mice with inflamed bowels using aptamer-functionalized microbubbles in comparison to non-targeted microbubbles. There was no signal in healthy mice (p = 0.4051) using either microbubble.

CONCLUSIONS

We constructed an aptamer-functionalized microbubble specific for P-selectin using a clinically relevant azide-DBCO click reaction, which could detect bowel inflammation in vivo. Aptamers have potential as a next generation targeting agent for developing cost-efficient and clinically translatable targeted microbubbles.

Usefulness of Intestinal Ultrasound to Detect Small Intestinal Stenosis in Patients With Crohn's Disease

OBJECTIVES

Double balloon enteroscopy (DBE) with retrograde contrast is useful as a monitoring tool for small intestinal lesions in Crohn's disease (CD), but these are burdensome for patients. Intestinal ultrasound (IUS) can be used with ease in daily clinical practice, but there is less evidence regarding the accuracy of detection of small intestinal stenosis in CD. This study aimed to examine the diagnostic power of IUS for small intestinal stenosis in patients with CD.

METHODS

The findings of DBE and IUS in 86 patients with CD with small intestinal lesions were evaluated. Using DBE as the reference standard, we examined the detection rate of IUS for small intestinal stenosis. We evaluated three parameters: luminal narrowing, prestenotic dilation, and to-and-fro movement for determining stenosis using IUS. In addition, we compared the characteristics between the stenosis-detectable and stenosis-undetectable groups by IUS.

RESULTS

Of the 86 patients, 30 had small intestinal stenosis. In IUS findings, when lesions that met two or more of the three parameters were judged as stenosis, the detection rate was 70.0% for sensitivity, 98.2% for specificity, and 88.4% for accuracy. Moreover, there were patients with a younger age at diagnosis (P < 0.05) and more ileocolonic disease location (P < 0.05) in the stenosis-detectable group by IUS. The stenoses detected by IUS were significantly longer than those undetected by IUS (14.1 mm versus 5.2 mm, P < 0.05).

CONCLUSIONS

IUS delivered reliable results for clinically important small intestinal stenosis of CD with high diagnostic accuracy.

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.

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.

Treat to transmural healing: how to incorporate intestinal ultrasound into the treatment of inflammatory bowel disease

Intestinal ultrasound (IUS) is emerging as a key tool to achieving the therapeutic target of transmural healing in inflammatory bowel disease (IBD). IUS is a non-invasive, radiation-free, imaging modality comparable to MRI, CT and ileocolonoscopy (IC). With the appropriate training and equipment, IUS can be an easily repeatable bedside test for IBD diagnosis and disease monitoring, including treatment response. Core to successful high quality IUS employment are appropriate training and expert techniques; however, the training pathway will not be explored in this review. Given the increasing shift towards objective assessment for tight disease control, gastroenterologist-led IUS should be incorporated into the armamentarium of imaging modalities alongside radiologists, to enhance our diagnostic and monitoring toolbox. This comprehensive review aims to outline the current literature around IUS and propose the placement of IUS in a treat-to-target algorithm in IBD. Ultimately, IUS facilitates timely management decisions to optimise patient care with potential to revolutionise patient outcomes, moving towards transmural healing as the holy grail of therapy in IBD.

Intestinal Elastography in the Diagnostics of Ulcerative Colitis: A Narrative Review

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) that mainly affects developed countries, but the number of cases in developing countries is increasing. We conducted a narrative review on the potential application of ultrasound elastography in the diagnosis and monitoring of UC, as this newly emerging method has promising results in other gut diseases. This review fulfilled the PRISMA Statement criteria with a time cut-off of June 2022. At the end of the review, of the 1334 identified studies, only five fulfilled all the inclusion criteria. Due to the small number of studies in this field, a reliable assessment of the usefulness of ultrasound elastography is difficult. We can only conclude that the transabdominal elastography examination did not significantly differ from the standard gastrointestinal ultrasonography examination and that measurements of the frontal intestinal wall should be made in the longitudinal section. The reports suggest that it is impossible to estimate the clinical scales used in disease assessment solely on the basis of elastographic measurements. Due to the different inclusion criteria, measurement methodologies, and elastographic techniques used in the analysed studies, a reliable comparative evaluation was impossible. Further work is required to assess the validity of expanding gastrointestinal ultrasonography with elastography in the diagnosis and monitoring of UC.

Positioning intestinal ultrasound in a UK tertiary centre: significant estimated clinical role and cost savings

OBJECTIVE

Intestinal ultrasound (IUS) is an inexpensive, non-invasive method of diagnosing and monitoring inflammatory bowel disease (IBD). We aimed to establish the proportion of lower gastrointestinal endoscopies (LGIEs) and magnetic resonance enterographies (MREs) that could have been performed as IUS, the potential pathology miss-rates if IUS was used and the associated cost savings.

METHODS

All MREs and LGIEs performed for either assessment of IBD activity or investigation of possible IBD, performed at a single UK tertiary centre in January 2018, were retrospectively reviewed against predetermined criteria for IUS suitability. Case outcomes were recorded and cost of investigation if IUS was performed instead was calculated.

RESULTS

73 of 260 LGIEs (28.1%) and 58 of 105 MREs (55.2%) met the criteria for IUS suitability. Among potential IUS-suitable endoscopy patients, one case each of a <5 mm adenoma and sessile serrated lesion were found; no other significant pathology that would be expected to be missed with IUS was encountered. Among IUS-suitable MRE patients, no cases of isolated upper gastrointestinal inflammation likely to be missed by IUS were found, and extraintestinal findings not expected to be seen on IUS were of limited clinical significance. The predicted cost saving over 1 month if IUS was used instead was £8642, £25 866 and £5437 for MRE, colonoscopy and flexible sigmoidoscopy patients, respectively.

CONCLUSION

There is a significant role for IUS, with annual projected cost savings of up to almost £500 000 at our centre. Non-inflammatory or non-gastrointestinal pathology predicted to be missed in this cohort was of limited clinical significance.

Imaging in inflammatory bowel disease: current and future perspectives

The use of cross-sectional imaging and ultrasonography has long complemented endoscopic assessment of inflammatory bowel disease (IBD). Clinical symptoms alone are often not enough to assess disease activity, so a reliance on non-invasive techniques is essential. In this paper, we aim to examine the current use of radiological modalities in aiding the management of patients with IBD. We focus on the various sections of the gastrointestinal tract and how different modalities can aid in assessing current disease state and response to treatments. We also have a look at how newer sequences in cross-sectional imaging and ultrasonography can allow for better differentiation of disease activity (ie, fibrotic vs inflammatory) as well improve evaluation of small bowel, colonic and perianal disease. Furthermore, we examine how advanced image processing has the potential to allow radiology to be a surrogate for biomarkers. An example of this is explored when reviewing the ability of MR sequences to quantify visceral fat, which potentially plays a role in determining disease activity in Crohn's disease. Lastly, we look into the expected role for artificial intelligence to be used as an adjunct to radiology to better improve IBD evaluation.

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.

Fertility and Pregnancy in Crohn's Disease

The prevalence of inflammatory bowel disease is continuing to increase worldwide and is more commonly diagnosed in women of reproductive age. Individuals with Crohn's disease may have inaccurate perceptions regarding the rate of infertility, heritability, and the safety of taking therapies for Crohn's disease during pregnancy, all of which greatly affect their decisions surrounding family planning. Given this area of need for both patients and providers, in this article, we have included the latest evidence on the impact of Crohn's disease on fertility, heritability, pregnancy outcomes, and the safety of medications for Crohn's disease during pregnancy and lactation.

Ultrasonographic scores for ileal Crohn's disease assessment: Better, worse or the same as contrast-enhanced ultrasound?

BACKGROUND

Intestinal ultrasound (IUS) is an increasingly used non-invasive tool to evaluate Crohn's disease (CD) activity. Recently, two IUS scores that evaluate inflammatory activity have emerged: the Simple Ultrasound Activity Score for CD (SUS-CD) and the International Bowel Ultrasound Segmental Activity Score (IBUS-SAS). We aimed to compare the accuracy of SUS-CD, IBUS-SAS and contrast-enhanced ultrasound (CEUS) in predicting inflammatory activity in the terminal ileum in ileocolonoscopy in CD patients.

METHODS

Retrospective study including all consecutive CD patients submitted to IUS with CEUS directed to the terminal ileum performed by a single operator between April 2016 and March 2020. Segmental SUS-CD and IBUS-SAS were calculated. A time-intensity curve of the contrast bowel wall enhancement was created with measurement of peak intensity using CEUS. The CD endoscopic activity in ileocolonoscopy was graded by Simple Endoscopic Score for CD (SES-CD) as inactive (SES-CD < 7) or active (SES-CD ≥ 7).

RESULTS

Fifty patients were included, 54.0% were female, with mean age of 34 ± 12 years, and most had isolated ileal disease (60.0%), and a nonstricturing, nonpenetrating behaviour (44.0%). Most of the patients (60.0%) had active endoscopic disease (SES-CD ≥ 7). SUS-CD and IBUS-SAS were not different between patients with active or inactive endoscopic disease (p = 0.15; 0.57, respectively), having a poor accuracy to correlate endoscopic activity (area under de curve (AUC) 0.62; 0.55, respectively). Peak intensity in CEUS was significantly different in patients with active or inactive endoscopic disease (p = 0.004), having a good accuracy to correlate endoscopic activity (AUC 0.80).

CONCLUSION

Unlike CEUS, SUS-CD and IBUS-SAS were not able to accurately correlate endoscopic activity in terminal ileum in CD. Therefore, CEUS is a non-invasive emerging method that should be increasingly integrated in the ultrasonographic evaluation of CD patients.

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.

Point-of-Care Testing and Home Testing: Pragmatic Considerations for Widespread Incorporation of Stool Tests, Serum Tests, and Intestinal Ultrasound

Breaking through the biologic therapy efficacy plateau for inflammatory bowel disease requires the strategic development of personalized biomarkers in the tight control model. After risk stratification early in the disease course, targeted serial monitoring consistently to assess clinical outcomes in response to therapy allows for quick therapeutic adjustments before bowel damage can occur. Point-of-care intestinal ultrasound performed by the treating gastroenterologist is an accurate cross- sectional biomarker that monitors intestinal inflammation in real-time, enhances patient care, and increases shared understanding to help achieve common treatment goals. Combining intestinal ultrasound during a clinic visit with existing serum and stool biomarkers in a home testing setup with electronic health monitoring allows for an optimized, patient-centered personalized treatment algorithm that may improve treatment outcomes. Here, we review the current state, pragmatic considerations, and future implications of point-of-care testing and home testing for noninvasive inflammatory bowel disease monitoring in the tight control model.

Intestinal ultrasonography and fecal calprotectin for monitoring inflammation of ileal Crohn's disease: two complementary tests

Background/Aims

Tight control of inflammation and adjustment of treatment if activity persists is the current strategy for the management of Crohn’s disease (CD). The usefulness of fecal calprotectin (FC) in isolated involvement of the small intestine in CD is controversial. To assess the usefulness of FC to determine the inflammatory activity detected by intestinal ultrasonography (IUS) in ileal CD.

Methods

Patients with exclusively ileal involvement CD who underwent IUS and an FC were prospectively included. Simple ultrasound index was used to determine inflammatory activity. The usual statistical tests for comparison of diagnostic techniques were used.

Results

One hundred and five patients were included, IUS showed inflammatory activity in 59% of patients and complications in 18.1%. FC showed a significant correlation with IUS in the weak range (Spearman coefficient r=0.502; P<0.001); the area under the receiver operating characteristic curve was 0.79 (95% confidence interval, 0.70–0.88; P<0.001). The FC value that best reflected the activity in IUS was 100 μg/g with sensitivity, specificity, and positive and negative predictive values of 73.0%, 71.4%, 79.3% and 63.8%, respectively. There were no differences in FC concentration between patients with or without transmural complications. The addition of serum C-reactive protein to FC did not improve the ability to assess IUS activity.

Conclusions

FC has a significant correlation with IUS to monitor ileal CD activity. This correlation is weak and it does not allow assessing the presence of CD complications. Both tests should be used in conjunction for tight control of ileal CD. More studies on noninvasive tests in this location are needed.

Innovative Care for Inflammatory Bowel Disease Patients during the COVID-19 Pandemic: Use of Bedside Intestinal Ultrasound to Optimize Management

Background

The COVID-19 pandemic caused by SARS-CoV-2 has reduced access to endoscopy and imaging. Safe alternatives, available at the bedside, are needed for accurate, non-invasive strategies to evaluate disease activity. The aim of this study is to establish the impact of clinic-based bedside intestinal ultrasound (IUS) on decision making, reduction in reliance on endoscopy and short-term healthcare utilization.

Methods

We conducted a prospective observational evaluation during the COVID-19 pandemic, of the impact of a regional comprehensive care pathway to manage IBD patients consecutively recruited with acute symptoms, or suspected new diagnosis of IBD. Clinic-based access to sigmoidoscopy and bedside intestinal ultrasound were evaluated, used to direct clinical care and avoid hospitalization or hospital-based endoscopy.

Results

A total of 72 patients were seen between March 15 and June 30, 2020. Of these, 57% (41/72) were female, 64% had Crohn's disease (46/72) with 14% (10/72) presenting with symptoms requiring investigation, of which 5 new cases of IBD were identified (50%). Immediate access to ultrasound and sigmoidoscopy led to meaningful changes in management in 80.5% (58/72) of patients. Active inflammation was detected by IUS alone (72.5%, 29/40) or in combination with in-clinic sigmoidoscopy (78%, 18/23) or sigmoidoscopy alone (78% 7/9). Six patients were referred to colorectal surgery for urgent surgical intervention including two patients admitted directly.

Conclusion

Implementation of IUS as part of a clinical care pathway during the COVID-19 pandemic is a useful strategy to enhance care delivery and improve clinical decisions, while sparing other important acute care resources.

A systematic monitoring approach to biologic therapies in inflammatory bowel disease: patients' and physicians' preferences and adherence

OBJECTIVES

Treatment of patients with inflammatory bowel disease (IBD) should aim at achieving mucosal healing. However, monitoring schedules to support this goal remain undefined. We aimed to identify patients' and physicians' preferences regarding monitoring strategy and investigated the feasibility of such a strategy.

METHODS

Elements considered relevant for monitoring were identified in questionnaire surveys among 1) patients with IBD receiving biologic agents (n = 172) and 2) their physicians (n = 87). Adherence to a monitoring strategy incorporating these elements was investigated in a retrospective cohort of patients with IBD treated with biologic agents (n = 139).

RESULTS

Patients considered blood and stool samples, endoscopies, and magnetic resonance imaging (MRI) to be relevant aspects of monitoring their disease. However, patients also considered stool samples and endoscopies unpleasant. Physicians considered blood samples (99%), medical consultations (99%), fecal calprotectin (85%), endoscopy (78%), and MRI (71%) to be important aspects of IBD monitoring but considered endoscopies and MRI relevant only at clinical signs of relapse. A review of the clinical use of monitoring strategies including the elements identified above revealed high adherence for blood samples and disease activity indices (92%), but low adherence for fecal calprotectin (38%), therapeutic drug monitoring (38%), and endoscopies (32%).

CONCLUSION

Important tools for evaluating mucosal healing (e.g., endoscopy) were rated highly unpleasant by patients, and physicians found endoscopies/MRI relevant only in case of relapse. These findings were reflected by low rates of adherence to use of these monitoring tools. In defining monitoring schedules to help achieve treatment goals, these important barriers must be addressed.

Review article: randomised controlled trials in inflammatory bowel disease-common challenges and potential solutions

BACKGROUND

Recruitment rates for Crohn's disease and ulcerative colitis clinical trials continue to decrease annually. The inability to reach recruitment targets and complete trials has serious implications for stakeholders in the inflammatory bowel disease (IBD) community. Action is required to ensure patients with an unmet medical need have access to new therapies to improve the management of their IBD.

AIMS

Identify challenges contributing to recruitment decline in IBD clinical trials and propose potential solutions.

METHODS

PubMed and Google were used to identify literature, regulatory guidelines and conference proceedings related to IBD clinical trials and related concepts. Data on IBD clinical trials conducted between 1989 and 2020 were extracted from the Trialtrove database.

RESULTS

Key aspects that may improve recruitment rates were identified. An increasingly patient-centric approach should be taken to study design including improvements to the readability of key trial documentation and inclusion of patient representatives in trial planning. Placebo is unappealing to patients; approaches including platform trials should be explored to minimise placebo exposure. Non-invasive imaging, biomarkers and novel digital endpoints should continue to be examined to reduce the burden on patients. Reducing the administrative burden associated with trials via the use of electronic signatures, for example, may benefit study sites and investigators. Changes implemented to IBD trials during the COVID-19 pandemic provided examples of how trial conduct can be rapidly and constructively adapted.

CONCLUSIONS

To improve recruitment in Crohn's disease and ulcerative colitis trials, the IBD community should address a broad range of issues related to clinical trial conduct.

The Use of Transabdominal Ultrasound in Inflammatory Bowel Disease

Transabdominal ultrasound (TAUS) is useful in all aspects of lesion screening, monitoring activity, or treating/diagnosing any related complications of inflammatory bowel disease. Its ability to screen or diagnose complications is almost the same as that of other methods, such as CT or MRI. Moreover, its noninvasiveness makes it a first-line examination method. A TAUS image depicting ulcerative colitis will show large intestinal wall thickening that is continuous from the rectum, which is mainly due to mucosal layer thickening, while for Crohn’s disease, a TAUS image is characterized by a diversity in the areas affected, distribution, and layer structure. Indicators of activity monitoring include wall thickness, wall structure, and vascular tests that use Doppler ultrasound or contrast agents. While all of these have been reported to be useful, at this time, no single parameter has been established as superior to others; therefore, a comprehensive evaluation of these parameters is justified. In addition, evaluating the elasticity of lesions using elastography is particularly useful for distinguishing between fibrous and inflammatory stenoses. However, the lack of objectivity is the biggest drawback of using ultrasound. Standardizing and popularizing the ultrasound process will be necessary, including scanning methods, equipment settings, and image analysis.

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.

Accuracy of Gastrointestinal Ultrasound and Calprotectin in the Assessment of Inflammation and its Location in Patients with an Ileoanal Pouch

BACKGROUND AND AIMS

In symptomatic patients with ileoanal pouches, pouchoscopy is needed for accurate diagnosis but is invasive. We aimed to assess the utility of non-invasive gastrointestinal ultrasound and faecal calprotectin in ileoanal pouch patients.

METHODS

Patients with an ileoanal pouch were consecutively enrolled in this cross-sectional study from clinics in Victoria, Australia. The pouchitis disease activity index was used as a reference standard. Video-recorded pouchoscopies were reviewed by three gastroenterologists. Pouch, pre-pouch, and cuff biopsies were reviewed by a single pathologist. Ultrasound was performed by a single gastroenterologist transabdominally and transperineally. Faecal calprotectin was measured from morning stool samples. All examiners were blinded to patients' clinical history.

RESULTS

A total of 44 participants had a pouchoscopy, of whom 43 had a faecal calprotectin test and 42 had an ultrasound; 17 had pouchitis, 15 had pre-pouch ileitis, and 16 had cuffitis. Pouch wall thickness of <3 mm was 88% sensitive in excluding pouchitis, and pouch wall thickness of ≥4 mm was 87% specific in diagnosing pouchitis. Transabdominal ultrasound had good utility [area under the curve: 0.78] in diagnosing moderate-severe pre-pouch ileitis. Transperineal ultrasound had good utility for the diagnosis of pouchitis [area under the curve: 0.79]. Faecal calprotectin differentiated inflammatory from non-inflammatory pouch disorders, such as irritable pouch syndrome, with an area under the curve of 0.90. Faecal calprotectin <100 µg/g ruled out inflammatory pouch disorders with a sensitivity of 94%.

CONCLUSIONS

Faecal calprotectin and ultrasound are accurate and complementary tests to diagnose and localise inflammation of the ileoanal pouch. Prospective studies are needed to validate proposed sonographic indices and calprotectin levels.

Transmural Response and Transmural Healing Defined by Intestinal Ultrasound: New Potential Therapeutic Targets?

BACKGROUND AND AIMS

Intestinal ultrasound [IUS] is a useful modality to monitor patients with inflammatory bowel disease [IBD]. Little is known about the use of IUS and appropriate definitions for transmural response [TR] and healing [TH]. We aimed to establish the use of IUS in monitoring TH as a potential target in routine medical practice.

METHODS

Based on the prospective, non-interventional, multicentre studies TRUST and TRUST&UC, we conducted a post-hoc analysis of 351 IBD patients with increased bowel wall thickness [BWT]. We analysed the rates of patients achieving TR and TH, comparing three definitions of TH. In 137 Crohn's disease [CD] patients, the predictive value of TR and TH was investigated for the clinical and sonographic outcome at week 52.

RESULTS

Within 12 weeks of treatment intensification, 65.6% [n = 118] of CD patients and 76.6% [n = 131] of ulcerative colitis [UC] patients showed a TR. Depending on the definition, 23.9-37.2% [n = 58/67/43] of CD patients and 45.0-61.4% [n = 90/105/77] of UC patients had TH at week 12. CD patients with TH were more likely to reach clinical remission at week 12 (odds ratio [OR] 3.33 [1.09-10.2]; p = 0.044) and a favourable sonographic outcome (OR 5.59 [1.97-15.8]; p = 0.001) at week 52 compared with patients without TH.

CONCLUSIONS

IUS response and TH in a relevant proportion of patients suggests that IUS is a useful method to assess transmural inflammatory activity in daily clinical practice. TR and TH are predictive for the sonographic outcome at week 52.

Ultrasound use to assess Crohn's disease in the UK: a survey of British Society of Gastroenterology Inflammatory Bowel Disease Group members

BACKGROUND

Small bowel ultrasound has very good diagnostic accuracy for disease extent, presence and activity in Crohn's Disease, is well tolerated by patients and is cheaper when compared with MRI. However, uptake of ultrasound in the UK is limited.

METHODS

An online survey to assess the current usage of ultrasound throughout the UK was undertaken by BSG IBD group members between 9/06/2021- 25/06/2021. Responses were anonymous.

RESULTS

103 responses were included in the data analysis. Responses came from 66 different NHS trusts from 14 different regions of the UK. All respondents reported that they currently have an MRI service for Crohn's disease, whereas only 31 had an ultrasound service. Average time for results to be reported for MRI scans was reported as between 4- and 6 weeks, with a range of 2 days to 28 weeks. The average time for an ultrasound to be reported was stated as 1-4 weeks, with a range of 0-8 weeks. There was disparity between the reported confidence of clinicians making clinical decisions when using ultrasound compared to MRI. Of those respondents who did not have access to an ultrasound service, 72 stated that they would be interested in developing an ultrasound service.

CONCLUSION

There is an appetite for the uptake of ultrasound in the UK for assessment of Crohn's disease, however, there remains a significant number of UK centres with little or no access to an ultrasound service. Further research is necessary to understand why this is the case.