We aimed to compare two main existing scores, the Bowel Ultrasound Score (BUSS) and the International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) to predict simplified endoscopic activity score for Crohn's disease (SES-CD).

A cross-sectional study was conducted to evaluate the disease activity in Crohn's disease (CD) patients with ileal involvement between November 2019 and February 2024. Endoscopic remission for CD was accepted as SES-CD ≤2.

A total of 56 adult patients with CD (male: 38, 68%, median age: 40.5 years) were included in the study, the median duration of the disease was 8.4 years. The cutoff value for BUSS to determine endoscopic remission was 3.9, whereas the cutoff value for IBUS-SAS to establish endoscopic remission was 24.4. BUSS and SES-CD had a strong positive correlation ( P  < 0.001), BUSS and IBUS-SAS had a high positive correlation ( P  < 0.001), and BUSS and C-reactive protein had a slightly positive correlation ( P  < 0.001).

This study revealed that the cutoff values for BUSS and IBUS-SAS in CD patients with endoscopic remission were 3.9 and 24.4, respectively. Furthermore, it was demonstrated that BUSS and IBUS-SAS highly correlate with endoscopic activity in the real-world cohort.

The development of noninvasive markers to assess mucosal healing in ulcerative colitis (UC) is essential in the treat-to-target era. The aim of this study was to evaluate the performance of intestinal ultrasound (IUS), fecal calprotectin (FC), and their combination to assess mucosal healing in UC patients.

All consecutive patients between January 2021 and September 2022 with UC who underwent a complete colonoscopy and IUS and/or an FC test within 4 weeks were included in a prospective cohort. Bowel wall thickness (BWT) and the color Doppler signal (CDS) were assessed for each segment. Endoscopic mucosal healing was defined by a Mayo score of 0 to 1.

A total of 61 patients were included, of whom 79% showed endoscopic healing (26 Mayo 0 and 11 Mayo 1). Among the patients, 16 (27.6%) of 58 had a BWT <3 mm, and 41 (70.7%) of 58 had no CDS. The sensitivity, specificity, positive predictive value, and negative predictive value of a BWT <3 mm to predict endoscopic mucosal healing were 37%, 77%, 72%, and 44%, respectively. The association of FC <150 µg/g, a BWT <3 mm, and a CDS = 0 increased the specificity and positive predictive value (sensitivity 33%, specificity 94%, positive predictive value 89%, negative predictive value 48%). The combination of a normal IUS, no rectal bleeding, and an FC <172 µg/g identified all patients with mucosal healing.

The combination of IUS and FC is effective in identifying mucosal healing in UC. Noninvasive evaluation of mucosal healing is possible for most UC patients.

Stride-II recommends monitoring early biomarker targets to achieve treat-to-target (T2T) endoscopic remission (ER) in ulcerative colitis (UC). Predictive capabilities of intestinal ultrasound (IUS) for ER remain unknown. We evaluated IUS response to predict ER in children with UC.

Prospective longitudinal cohort study of children with UC (Mayo endoscopic score [MES ≥2) starting advanced therapy undergoing IUS (including Milan Ultrasound Criteria [MUC], Civitelli Ulcerative Colitis Index, and International Bowel Ultrasound Group Segmental Activity Score), fecal calprotectin (FC), C-reactive protein (CRP), and Pediatric Ulcerative Colitis Activity Index at baseline, week 8, and T2T. Primary outcome was accuracy to predict T2T ER (MES = 0) for change in bowel wall thickness (BWT) from baseline to week 8, and absolute BWT at week 8. Logistic regression with forward selection determined an optimal prediction model for endoscopic outcomes.

Of 42 children, 21 (50%) achieved ER. Week 8 BWT ≤ 2.7 mm (OR 6.4 [95% CI, 1.8-27.0], P = .007), MUC < 6.0 (OR 5.7 [95% CI, 1.5-25.3], P = .015), and FC ≤ 177 (OR 4.5 [95% CI, 1.1-23.6], P = .049) were associated with ER.

Combining noninvasive biomarkers of BWT and the MUC on IUS, and FC, is a feasible tight control monitoring strategy in children with UC that is predictive of endoscopic outcomes. Larger, multicenter validation studies are needed to understand how an IUS and FC monitoring strategy may improve outcomes in children with UC.

The International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) is an intestinal ultrasound (IUS) score validated for Crohn's disease, potentially applicable to ulcerative colitis (UC). We aimed to confirm the applicability of IBUS-SAS to UC, while comparing its performance with other IUS scores.

Adult patients with UC undergoing colonoscopy were prospectively included and scored with both the Mayo Endoscopic Subscore (MES) and the Ulcerative Colitis Endoscopic Index of Severity (UCEIS). Intestinal ultrasound was performed within 4 weeks of endoscopy, measuring IBUS-SAS and other 5 UC-developed IUS scores. The Spearman's rank coefficient (ρ) was used to perform correlations, while receiver operating characteristic curves were compared with the Hanley & McNeil method.

In total, 185 patients were included. The IBUS-SAS showed a strong correlation with both the MES (ρ = .72, P < .01) and the UCEIS (ρ = .73, P < .01). Its area under the curve to detect an endoscopic activity of at least moderate severity (MES ≥ 2 and UCEIS ≥ 5) was 0.87 and 0.89, respectively. The optimal cutoffs of IBUS-SAS to detect a MES ≥ 2 and an UCEIS ≥ 5 were > 19 (sensitivity 79%, specificity 84%) and > 23 (sensitivity 88%, specificity 75%), respectively. Consistently, all the investigated IUS scores correlated with both the MES and the UCEIS (P < .01).

The IBUS-SAS has an optimal performance in the assessment of UC endoscopic activity, despite having been initially developed for CD. Therefore, it might be adopted as a reference score both for CD and UC activity.

Fecal calprotectin (Fcal) and intestinal ultrasonography (IUS) could be used as noninvasive tools to monitor mucosal and transmural healing, respectively, in Crohn's disease (CD). We assessed the agreement between Fcal and IUS to detect active CD and investigated their complementary to predict long-term CD outcomes.

In this prospective study, we consecutively included CD patients with concomitant IUS and Fcal testing within 7 days. Patients were divided into 4 groups: Transmural healing (TH; both normal), IUS healing (Fcal > 100 µg/g but normal IUS), biochemical remission reflecting mucosal healing (MH; Fcal < 100 µg/g but abnormal IUS), and no healing (abnormal Fcal and IUS). The primary endpoint was active CD. The secondary endpoints were time to bowel damage progression, time to relapse-related drug discontinuation, and patients' acceptability (10-points acceptability numerical scale).

Among the included 112 patients, 44.6% (50/112), 12.5% (14/112),16.1% (18/112), and 26.8% (30/122) achieved TH, IUS healing, biochemical remission, and no healing, respectively. The agreement between IUS and Fcal to detect an active CD was poor (71.4%, κ-coefficient = 0.41 ± 0.09). Transmural healing was associated with a reduced risk of bowel damage progression compared to no healing (P < .0001) contrary to IUS healing (P = .15) or biochemical remission (P = .84). Transmural healing was associated with a lower risk of relapse-related drug discontinuation than MH (hazard ratio [HR] = 0.09 [0.02-0.45], P = .003), IUS healing (HR = 0.10 [0.02-0.60], P = .001), or no healing (HR = 0.09 [0.018-0.04], P = .002). IUS was better accepted than Fcal testing (9.6 ± 0.8 vs 7.9 ± 2.3; P < .0001, 10-points range-acceptability numerical scale).

Transmural healing, evaluated by the combination of noninvasive and well-accepted tools such as Fcal and IUS, is associated with improved long-term outcomes and could be used to monitor patients with CD in daily practice.

Assessment of small bowel involvement when diagnosing inflammatory bowel disease (IBD) delineates clinical subtype and disease extension. The gold standard for small bowel assessment is magnetic resonance enterography (MRE), but MRE is not always feasible for children. Standard, non-contrast enhanced abdominal ultrasound is an acceptable alternative. The study aimed to evaluate the utility of ultrasound in the diagnostic work-up of pediatric IBD to identify small bowel involvement.

A retrospective study was conducted among children (< 18 years) who had abdominal ultrasound during assessment for IBD (2019-2023) at Christchurch Hospital, New Zealand. Descriptive analysis compares small bowel ultrasound to MRE, endoscopy and histology.

The cohort comprised 47 children, mean age 9.9 years (± 4.1), 23 (49%) males and 42 (89%) with Crohn's disease. All had endoscopy and histology data available for comparison, and 26 had MRE. Fourteen (30%) had no small bowel disease on ultrasound, MRE, endoscopy, or histology. Ultrasound confirmed small bowel disease diagnosed by other modalities for 12 (26%). Ultrasound identified small bowel disease for 7 (15%) that had not been seen during the diagnostic process by MRE, endoscopy or histology, possibly due to the limitations of endoscopy and time-delays between diagnosis and MRE. Small bowel disease was not picked up on ultrasound for 14 (30%) children, disease locations being duodenum (n = 6), TI (n = 5), proximal ileum (n = 3), and jejunum (n = 2).

Abdominal ultrasound is a valuable resource for assessing disease extent in suspected pediatric IBD. This study highlights the clinical benefit and feasibility of a multi-modal diagnostic approach.

The aetiology of Crohn's disease, a chronic inflammatory bowel disease, is multifactorial and not completely understood. However, the association with gut dysbiosis is well-established, and manipulation of the gut microbiota has gained interest as a treatment strategy. This study aimed to investigate the effects of the probiotic strain Bifidobacterium breve, Bif195™ (Bif195) on intestinal inflammation, symptoms, and the gut microbiome composition in patients with small intestinal Crohn's disease.

This was a randomised, double-blind, placebo-controlled trial. Thirty-three patients with small intestinal Crohn's disease were assigned to eight weeks of treatment with Bif195 or placebo (1:1). The primary outcome was changes in bowel wall thickness measured by intestinal ultrasonography. Other outcomes were changes in symptom severity, quality of life, faecal calprotectin, fatigue, and specific inflammatory parameters on ultrasonography. Changes in the microbiome composition were also examined.

Bif195 did not affect the bowel wall thickness in the small intestine compared to placebo. Nor did we observe effects on secondary or clinical explorative outcomes. Analysis of the gut microbiome showed that the relative abundance of B. breve rose during the intervention in the Bif195 group, but the result was statistically non-significant. Surprisingly, we observed a clustering of baseline microbiome data into two groups that differed in several aspects including a statistically significant difference in the incidence of previous bowel resections among the participants. Furthermore, changes in symptom scores after eight weeks of intervention were significantly different across the two microbiome groups, with an interaction effect of p = 0.04.

Eight weeks of treatment with Bif195 did not affect clinical outcomes for Crohn's disease. However, variations in baseline microbiome data influenced the results. This underscores the importance of assessing baseline microbiome data in intervention studies in Crohn's disease.

gov NCT04842149.

This study assesses the prognostic role of intestinal ultrasound (IUS) in determining the disease course of ulcerative colitis (UC) in the first year after diagnosis.

A prospective, multicenter population-based inception cohort study was conducted on patients newly diagnosed with UC. Patients with left-sided or extensive UC underwent IUS assessments at diagnosis, 3 months, and 12 months, alongside symptomatic, biochemical, and endoscopic evaluations. Transmural remission was defined as bowel wall thickness ≤3 mm without color Doppler signal in all segments.

From May 2021 to April 2023, 193 patients with left-sided or extensive UC were included. Inflammatory findings on IUS at diagnosis were associated with symptomatic, biochemical, and endoscopic markers of inflammation, but not with diagnostic delay. IUS-detected inflammation at diagnosis was an independent predictor for colectomy within the first 3 months, with bowel wall thickness >6 mm as the optimal cutoff (odds ratio 38, 95% confidence interval, 8-270, P < .0001). Three months after diagnosis, 59% of patients achieved transmural remission, which was associated with higher rates of steroid-free clinical remission in all subsequent follow-ups, as well as a reduced need for steroids during follow-up (6% vs. 19%, P = .036). Furthermore, transmural remission at 3 months increased the likelihood of steroid-free clinical remission, as well as transmural and complete remission, at 12 months.

Findings by IUS at the time of diagnosis predict early colectomy risk in UC. Our results underscore that transmural remission is a feasible treatment target in early UC, and significantly impacts the disease course.

Inflammatory bowel diseases (IBD), Crohn's disease (CD), and ulcerative colitis (UC) are lifelong chronic, relapsing, and remitting conditions that culminate in disease progression in many patients. Effective management of CD and UC requires consideration of both short- and long-term treatment outcomes. Historically, short-term outcomes such as clinical and endoscopic remission and symptom relief have been evaluated in clinical trials. With the expansion of treatments targeting underlying disease pathophysiology, there is the opportunity to develop management strategies that improve disease control and patients' lives in both the short and the long term. Researchers have been examining novel outcomes for assessing the efficacy of CD and UC treatments that are important to patients, and also those that go beyond symptomatic improvements or clinical remission. These include new patient-reported outcomes for symptoms, as well as transmural/histological healing and disease clearance that can be more reflective of deeper remission states and disease modification. This review analyses published clinical studies involving patients with UC and CD treated with biologics or small molecule therapies. It highlights novel IBD endpoints employed in published clinical trials and discusses their likely value for assessing disease activity and disease modification, and as predictors of reduced risk of complications and morbidities.

Advice to avoid dietary emulsifiers in Crohn's disease (CD) is based on preclinical data.

To examine the effect of diets high (HED) and low (LED) in emulsifiers in the food supply on disease activity in CD.

In a double-blinded, randomised feeding study, we randomised adults with symptomatic, sonographically active CD with ileal involvement on ≥ 2 months' stable medical therapy to 4 weeks of a HED or LED modelled on Australian healthy eating guidelines. We measured the Harvey-Bradshaw Index (HBI), sonographic indices (IBUS-SAS, bowel wall thickness), quality of life (QOL) and fatigue at baseline and study completion.

We randomised 24 patients, mean age 37 (95% CI 32, 41) years, 12 male, HBI 6 (6, 8), bowel wall thickness 6.0 (5.5-6.6) mm. Adherence was > 95%. Clinical remission (HBI < 5) occurred in 9/12 on HED and 7/12 on LED; 2 and 3, respectively, withdrew early with increasing gastrointestinal symptoms. IBUS-SAS fell from 51 (35, 68) to 33 (15, 51) on HED (p = 0.014) and from 57 (38, 76) to 44 (29, 59) on LED (p = 0.01). Bowel wall thickness reduced by 34% on HED and 15% on LED in those who completed the study. QOL and fatigue improved on both diets (p ≤ 0.05). There were no statistically significant differences in outcomes between diets.

In the context of a healthy diet, the emulsifier content had no influence over disease activity over 4 weeks in patients with CD. Recommendations to avoid emulsifiers in patients with active CD are not supported. Australian New Zealand Clinical Trials Registry (ACTRN12619001099112).

Gastrointestinal ultrasound (GIUS) is recommended for monitoring Crohn's disease (CD). GIUS scores are used to quantify CD activity. Among them, International Bowel Ultrasound Segmental Activity Score (IBUS-SAS), Bowel Ultrasound Score (BUSS), Simple Ultrasound Score, and Simple Ultrasound Score for Crohn's Disease are most commonly used. The aim of this study was to compare and correlate the performance of such indicators with endoscopic activity and to calculate interobserver agreement.

Consecutive patients with CD at our hospital between June 2015 and July 2021 were retrospectively enrolled. All patients underwent ileocolonoscopy after medical treatment. GIUS was performed within 2 weeks, and 4 GIUS scores were independently calculated. Receiver operating characteristic curve analyses were used to determine a cutoff value. Cohen kappa (κ) coefficient was calculated to estimate the agreement between GIUS findings.

A total of 106 patients with CD were enrolled. 80.2% (85/106) were endoscopic active (Simple Endoscopic Score for Crohn's disease ≥3), and 8.49% (9/106) were severe cases (Simple Endoscopic Score for Crohn's disease ≥9). All GIUS features (bowel wall thickness, color Doppler signs, bowel wall stratification, inflammatory signals at the mesentery) were statistically significant in assessing CD activity ( P < 0.05). IBUS-SAS showed the highest area under the curve (0.98; 95% CI: 0.96-1.00) and specificity (95.2%) for a cutoff value of 46.50. However, IBUS-SAS had only moderate agreement (Cohen κ = 0.427; P < 0.001). BUSS had substantial interobserver agreement (Cohen κ = 0.947; P < 0.001), with a similar diagnostic value (sensitivity, 100.0%; accuracy, 95.3%; area under the curve of 0.96 [95% CI: 0.91-1.00] for a cutoff value of 4.58).

GIUS score is an efficient and reliable method to assess CD activity. BUSS achieved a high accuracy and excellent interobserver agreement, which is more suitable for treatment assessment.

Imaging is essential in assessing patients with Crohn's disease, and it provides important and complementary information to the clinical and endoscopic findings. Patients can be accurately phenotyped and complications identified.

Treat-to-target therapy in inflammatory bowel disease requires longitudinal assessment of disease activity and intestinal ultrasound (IUS) is a promising non-invasive and cheap technology to provide objective read-outs. Vascularization of the bowel wall is one key parameter on IUS. While this is conventionally done with Color doppler imaging, it is currently unclear whether microvascular flow imaging techniques might improve the diagnostic performance of IUS.

To explore the utility of superb microvascular imaging (SMI) for assessing disease activity in Crohn's disease (CD).

We performed a prospective single-center cross-sectional cohort study including 56 patients with CD. IUS was performed on the terminal ileum or sigmoid colon within 30 days of colonoscopy and the International Bowel Ultrasound (IBUS) group Segmental Activity Score (SAS) as well as SMI signals were determined and correlated to established endoscopic, clinical and biochemical read-outs of disease activity.

SMI scores showed superior correlation to endoscopic disease activity than Doppler imaging scores. While this did not further improve the diagnostic performance of the composite IBUS-SAS, SMI scores as a single parameter excellently predicted segmental endoscopic disease activity.

SMI is a highly promising tool to improve or simplify the non-invasive assessment of disease activity in CD that should further be investigated in real-world and multi-center trials.

We characterize the sonographic features of Crohn's disease at diagnosis and evaluate the prognostic value of intestinal ultrasound during the early stage of disease.

A prospective, population-based cohort of patients with newly diagnosed Crohn's disease were followed with intestinal ultrasound in conjunction with symptomatic, biochemical, and endoscopic evaluations.

Between May 2021 and April 2023, 201 patients with adult-onset Crohn's disease were recruited. No associations were found between sonographic inflammation at diagnosis and diagnostic delay. After 3 months, transmural remission was achieved in 38% of patients, with patients with colonic disease achieving transmural remission more often. Transmural remission at 3 months was significantly associated with steroid-free clinical remission at 3 months and all subsequent follow-ups within the first year. Transmural remission was also associated with a lower risk of treatment escalation during follow-up until 12 months (26% vs 53%; P = .003). At 12 months, 41% had achieved transmural remission. Higher baseline body mass index negatively impacted the likelihood of 12-month transmural remission significantly (overweight: odds ratio [OR], 0.34; 95% confidence interval [CI],0.12-0.94; obese: OR, 0.16; 95% CI, 0.04-0.73). The International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) in the terminal ileum at diagnosis was the best predictor of ileocecal resection during the first year, with an optimal threshold of 63 (area under the curve [AUC], 0.92; sensitivity, 100%; specificity, 73%).

Transmural remission is an achievable outcome target for many patients with newly diagnosed Crohn's disease and is associated with a favorable clinical outcome, including sustained steroid-free clinical remission. Further, intestinal ultrasound findings at diagnosis predict future ileocecal resection.

There is an unmet medical need for noninvasive techniques to determine disease activity in inflammatory bowel disease (IBD) and intestinal ultrasound (IUS) has shown promising performance in this regard. In addition to parameters such as bowel wall thickness, stratification, and mesenteric fat, color Doppler signals are used to determine inflammatory activity in the gut. However, whether superb microvascular imaging (SMI), a microvascular flow imaging technique, improves the diagnostic accuracy is currently unclear.

We performed a prospective single-center cross-sectional cohort study including 62 patients with ulcerative colitis (UC). IUS was performed on the sigmoid colon within 30 days of colonoscopy and the International Bowel Ultrasound (IBUS) group Segmental Activity Score (SAS) as well as SMI signals were determined and correlated to established endoscopic, clinical, and biochemical read-outs of disease activity.

Semiquantitative scoring of SMI signals had a substantial interobserver agreement between 2 blinded and expert central readers. It showed excellent correlation to endoscopic, clinical, and biochemical disease activity. While SMI did not improve the overall diagnostic performance of the IBUS-SAS to predict endoscopic disease activity, SMI alone was highly precise and superior to Doppler imaging in predicting endoscopic remission.

IUS is a highly precise noninvasive diagnostic tool to monitor disease activity in UC, in particular for predicting endoscopic remission. Assessing the SMI signals in the bowel wall of patients with IBD seems a promising tool to simplify IUS diagnostics in IBD that warrants further research.

Intestinal ultrasound (IUS) has emerged as a valuable tool for monitoring inflammatory bowel disease (IBD), but its reliability depends on the technical skills of the operator.

This study aimed to assess the IUS learning curve of a novice briefly trained to get him familiarized with the ultrasound machine and normal/abnormal IUS images, and a gastroenterologist with formal general ultrasound training and regular IUS experience (> 200 exams), using an expert radiologist as the gold standard.

The ULTRA-IBD study was a single-center, prospective study involving 50 consecutive IBD patients. Three successive IUS examinations were performed on each patient by the 3 operators. Inter-rater agreement on IUS disease activity was calculated using the intraclass correlation coefficient.

The experienced gastroenterologist demonstrated consistently good agreement with the radiologist throughout the study, while the novice failed to go beyond poor agreement after 50 examinations, although a faster learning curve was observed in patients without history of IBD surgery.

These findings highlight the difficulty of the technical performance of IUS rather than its interpretation. Comprehensive ultrasound training beforehand and between 50 and 200 examinations of experience are necessary before embarking on IUS.

The comparable evaluation of computed tomography enterography (CTE), enteroscopy, and intestinal ultrasound in small bowel Crohn's disease (CD) is imprecise.

The purpose of this study was to analyze the findings of enteroscopy, CTE, and intestinal ultrasound to determine the advantages and disadvantages of each method for the evaluation of small bowel CD.

It was a single-center, observational, retrospective study.

The differences in localization of disease lesions, mucosal inflammation, and transmural inflammation between enteroscopy, CTE, and intestinal ultrasound for evaluation of small bowel CD were compared.

A total of 198 patients with small bowel CD were included in the analysis. CTE and intestinal ultrasound had a lower detection rate of upper intestinal lesions compared with enteroscopy (p < 0.05). Enteroscopy was better than CTE and intestinal ultrasound in the detection of stenosis (p < 0.001), and the assessment of fistula by CTE was better than that by enteroscopy and intestinal ultrasound (p < 0.05). Enteroscopy, CTE, and intestinal ultrasound differed in the assessment of inflammatory activity, and the agreement of the three methods was poor (all intra-class correlation coefficient <0.75).

Enteroscopy is superior to CTE and intestinal ultrasound for the assessment of upper intestinal CD lesions. Enteroscopy, CTE, and intestinal ultrasound were not consistent in evaluating inflammatory activity, and the three methods may need to be combined for an accurate assessment.

To assess transmural remission in patients with Crohn's disease using low-dose small bowel computed tomography (CT) perfusion scans.

Forty six patients were divided into active and remission phases based on Crohn's Disease Activity Index (CDAI) and C-reactive protein (CRP). Dual-source CT enterography with low-dose perfusion scans was conducted to generate perfusion parameter maps, including blood flow (BF), blood volume (BV), time to peak (TTP), mean transit time (MTT), and permeability of surface (PS). We compared differences in perfusion parameter values of intestinal walls, mesenteric fat, and lymph nodes between two groups. Receiver operating characteristic (ROC) curves were plotted, and area under the curve (AUC), sensitivity, specificity, and cutoff values were calculated.

The BF, BV, TTP, MTT, and PS values of the intestinal wall were significantly higher in the active phase (P0.05). Additionally, lymph node BF and TTP displayed significant differences (P<0.01).

Dual-source CT enterography with low-dose perfusion scans enables quantitative assessment of Crohn's disease microcirculation in intestinal walls, mesenteric fat, and lymph nodes. These quantitative indicators provide strong diagnostic efficacy and offer insights into whether the disease is in transmural remission.

Cross-sectional imaging, especially MR enterography (MRE) and intestinal US, plays an increasingly important role in the diagnosis and monitoring of Crohn disease. In this article, the authors share their approach to imaging Crohn disease, drawing on their clinical and research experience. They consider how to select the most appropriate modality for different clinical indications and discuss technical aspects to maximize diagnostic accuracy. The focus then shifts to how to use imaging to assess disease activity and treatment response in day-to-day clinical practice and the clinical potential of disease activity scores from MRE and intestinal US. The authors finish by discussing the benefits of intestinal US in ulcerative colitis.

Point-of-care ultrasound (POCUS) is changing the practice of nearly all specialties and is increasingly being incorporated as a bedside tool by more gastroenterologists and hepatologists. POCUS is most often used to answer focused diagnostic questions, supplement the traditional physical examination, and guide performance of invasive bedside procedures. This review describes several common POCUS applications used in gastroenterology and hepatology, as well as some novel applications that warrant further investigation.

In patients with chronic inflammatory bowel disease (IBD), endoscopic techniques (including capsule techniques and balloon enteroscopy for the small intestine), ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) are primarily used as often complementary imaging techniques. Radiation exposure needs to be kept in mind when using CT and conventional X‑ray-techniques. Therefore, most importantly, ultrasound and MRI have changed the routine diagnostics of intestinal diseases. US, CT and MRI not only assess the lumen but, similarly importantly, also the wall and the surrounding structures of the gastrointestinal tract. Furthermore, functional processes can be visualized and provide important information about passage and perfusion, which is mainly true for real-time ultrasound. CT and MRI are usually carried out with the use of contrast agents as contrast-enhanced CT (CECT) and contrast-enhanced MRI (CEMRI). Ultrasound is performed conventionally or with intravascular (CEUS) and/or extravascular intracavitary contrast agent application (icCEUS). This article provides an overview of the current significance of the mentioned imaging procedures in patients with IBD and discusses the typical indications.

Crohn's disease (CD) is a chronic, complex inflammatory disorder of the gastrointestinal tract that presents significant therapeutic challenges. Despite the availability of a wide range of treatments, many patients experience primary non-response, secondary loss of response, or adverse events, limiting the overall effectiveness of current therapies. Clinical trials often report response rates below 60%, partly due to stringent inclusion criteria. Emerging therapies that target novel pathways offer promise in overcoming these limitations. This review explores the latest investigational drugs in phases I, II, and III clinical trials for treating both luminal and perianal CD. We highlight promising therapies that target known mechanisms, including selective Janus kinase inhibitors, anti-adhesion molecules, tumor necrosis factor inhibitors, and IL-23 selective inhibitors. In addition, we delve into novel therapeutic strategies such as sphingosine-1-phosphate receptor modulators, miR-124 upregulators, anti-fractalkine (CX3CL1), anti-TL1A, peroxisome proliferator-activated receptor gamma agonists, TGFBRI/ALK5 inhibitors, anti-CCR9 agents, and other innovative small molecules, as well as combination therapies. These emerging approaches, by addressing new pathways and mechanisms of action, have the potential to surpass the limitations of existing treatments and significantly improve CD management. However, the path to developing new therapies for inflammatory bowel disease (IBD) is fraught with challenges, including complex trial designs, ethical concerns regarding placebo use, recruitment difficulties, and escalating costs. The landscape of IBD clinical trials is shifting toward greater inclusivity, improved patient diversity, and innovative trial designs, such as adaptive and Bayesian approaches, to address these challenges. By overcoming these obstacles, the drug development pipeline can advance more effective, accessible, and timely treatments for CD.

Small bowel video capsule endoscopy (SB-VCE) assesses mucosal inflammation in Crohn's disease (CD), while intestinal ultrasound (IUS) examines transmural involvement. We aimed to correlate SB-VCE with IUS in evaluating active CD and monitoring treatment response over time.

Patients with active SB-CD who initiated biologics were prospectively followed with fecal calprotectin (FC), SB-VCE, and IUS at baseline and after 14 and 52 weeks. The Lewis score (LS), Limberg index (LI), and terminal ileum bowel wall thickness (TI-BWT) were documented, and the International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) was retrospectively calculated. Biochemical, endoscopic, and ultrasonographic remission were defined as FC < 150 μg/g, LS < 135, and LI < 2 + TI-BWT ≤ 3 mm, respectively. A therapeutic response for each index was defined as a 25% reduction compared to baseline.

Seventy-one patients were included (median age: 30 years [23-43], 49.3% male). The median interval between SB-VCE and IUS was 3 days (0-25). Initially, the LS strongly correlated with TI-BWT (r = 0.647, P < .001), LI (r = 0.597, P < .001), and IBUS-SAS (r = 0.647, P < .001), but these correlations weakened over time (TI-BWT: r = 0.344, P = .002; LI: r = 0.471, P = .001; IBUS-SAS: r = 0.236, P = .122). Moderate agreement was found between ultrasonographic and endoscopic treatment responses (LS and TI-BWT: K = 0.51, P = .015; LS and LI: K = 0.44, P = .063), with fair agreement for remission (K = 0.27, P = .006). TI-BWT best cutoffs for mild (LS ≥ 135) and moderate-to-severe (LS ≥ 790) inflammation were 2.25 mm and 3.6 mm, respectively.

IUS measures are strongly correlated with VCE-inflammatory LS in active CD and may provide an assessment of endoscopic response and remission over time.

Diagnostic imaging using CT enterography, magnetic resonance enterography, and intestinal ultrasound are important tools in evaluating stricturing Crohn's disease. Definitions of strictures have been developed for CT enterography and magnetic resonance enterography. However, expert recommendations for definitions and treatment response of strictures on intestinal ultrasound are not available. The aim of this study was to standardise definitions, diagnosis, and treatment response criteria in small bowel stricturing Crohn's disease on intestinal ultrasound.

Using modified RAND-University of California Los Angeles Appropriateness Method, a diverse expert panel of 13 gastroenterologists, seven radiologists, and two patient representatives was assembled. A total of 466 statements on definitions and response to therapy of stricturing Crohn's disease on intestinal ultrasound were generated from a systematic review and from expert opinion, with subsequent rating for appropriateness. Two rounds of voting with an interposed survey result discussion were performed. Statements were classified as inappropriate, uncertain, or appropriate based on the median panel rating and degree of disagreement. Appropriateness was rated using a nine-point Likert scale (1 being inappropriate, 9 being highly appropriate).

A naive or anastomotic small bowel Crohn's disease stricture on intestinal ultrasound is defined by the combination of bowel wall thickening, luminal narrowing, and pre-stenotic dilation. Bowel wall thickness is defined as being more than 3 mm. Luminal narrowing is defined as either a luminal diameter reduction of more than 50% in the narrowest area and relative to a normal adjacent bowel loop, or a luminal diameter of less than 1 cm. Pre-stenotic dilation is defined as more than 2·5 cm or an increase in bowel diameter relative to a normal adjacent bowel loop. Definitions for grading hyperaemia, inflammatory fat, wall stratification, intestinal ultrasound machine technical parameters, and image acquisition were also devised. Treatment response of strictures was defined as reduction in stricture length, bowel wall thickening, luminal narrowing, pre-stenotic dilation, and motility abnormalities.

To our knowledge, this is the first intestinal ultrasound appropriateness rating exercise conducted for defining, diagnosing, and measuring response to therapy in small bowel stricturing Crohn's disease and informs future clinical use and intestinal ultrasound index development for clinical trials.

Leona M and Harry B Helmsley Charitable Trust.

Inflammatory bowel disease (IBD) follows a heterogenous disease course and predicting a patient's prognosis is challenging. There is a wide burden of illness in IBD and existing tools measure disease activity at a snapshot in time. Comprehensive assessment of IBD severity should incorporate disease activity, prognosis, and the impacts of disease on a patient. This review investigates the concept of disease severity in adults with IBD to highlight key components contributing to this.

To perform this narrative review, a Medline search was conducted for full-text articles available at 1st March 2024 using search terms which encompassed disease activity assessment, disease severity, prognosis, natural history of Crohn's disease (CD) and ulcerative colitis (UC), and the burden of IBD.

Current methods of disease assessment in IBD have evolved from a focus on the burden of symptoms to one that includes inflammatory targets, genetic, serological, and proteomic profiles, and assessments of quality-of-life (QoL), disability, and psychosocial health. Longitudinal studies of IBD suggest that the burden of illness is driven by disease phenotype, clinical markers of complicated disease course (previous intestinal resection, corticosteroid use, perianal disease in CD, recent hospitalisations in UC), gut inflammation, and the impact of IBD on the patient.

Disease severity in IBD can be difficult to conceptualise due to the multitude of factors that contribute to IBD outcomes. Measurement of IBD severity may better encapsulate the full burden of illness rather than gut inflammation alone at a single timepoint and may be associated with longitudinal outcomes.

Intestinal ultrasound (IUS) is becoming a standard assessment tool in Crohn's disease (CD), but limited data exist on its ability to predict long-term objective outcomes. Therefore, we aimed to investigate the predictive value of IUS findings for long-term transmural healing (TH) and mucosal healing (MH) in CD.

We prospectively included consecutive CD patients with active endoscopic disease and bowel wall thickness (BWT) >3.0 mm, initiating infliximab. Intestinal ultrasound parameters (ie, BWT, inflammatory mesenteric fat [i-fat], bowel blood flow and stratification) and International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) were collected at baseline, after 14 to 26 weeks (visit 1, postinduction) and 44 to 56 weeks (visit 2). Transmural healing (normalization of all IUS parameters) and MH (SES-CD ≤2) were assessed at visit 2.

One hundred twenty-nine patients were evaluated. At visit 2, 38.0% and 48.1% of patients achieved TH and MH, respectively. All the IUS parameters and IBUS-SAS showed improvement at visit 1 and visit 2 compared with the baseline (all P < .001). Multivariable analysis found that presence of i-fat at baseline (odds ratio [OR], 0.57; P = .008) and greater postinduction BWT (OR, 0.24; P < .001) were negative predictors for TH, while higher baseline (OR, 0.98; P = .013) and postinduction (OR, 0.94; P < .001) IBUS-SAS predicted negatively for MH. Postinduction BWT <4.5mm best predicted TH (AUC 0.85; P < .001), while postinduction IBUS-SAS <25.0 best predicted MH (AUC 0.82; P < .001). Moreover, colonic disease was associated with higher risk of TH (OR, 2.55; P = .027), and disease duration >24 months with lower risk of MH (OR, 0.27; P = .006).

Baseline and postinduction IUS findings reliably predict long-term TH and MH in patients with CD receiving infliximab.

This article extends on the use of transabdominal intestinal ultrasound in diagnosing pediatric inflammatory bowel disease. Some of the more essential features used in assessing bowel inflammation, such as hyperemia and wall thickness on ultrasound, are expanded upon from the publication on imaging and endoscopic tools in pediatric inflammatory bowel disease.

Magnetic resonance enterography [MRE] and intestinal ultrasound [IUS] have developed rapidly in the past few decades, emerging as the primary non-invasive options for both diagnosing and monitoring Crohn's disease [CD]. In this review, we evaluate the pertinent data relating to the use of MRE and IUS in CD. We summarise the key imaging features of CD activity, highlight their increasing role in both the clinical and the research settings, and discuss how these modalities fit within the diagnostic pathway. We discuss how they can be used to assess disease activity and treatment responsiveness, including the emergence of activity scores for standardised reporting. Additionally, we address areas of controversy such as the use of contrast agents, the role of diffusion-weighted imaging, and point-of-care ultrasound. We also highlight exciting new developments, including the applications of artificial intelligence. Finally, we provide suggestions for future research priorities.

In the past 3 years, the use of intestinal ultrasound (IUS) for monitoring inflammatory bowel disease in clinical practice has grown substantially in the United States. This American Gastroenterological Association (AGA) Institute Clinical Practice Update (CPU) aims to review the available evidence and guidance regarding the role of intestinal ultrasound in inflammatory bowel disease care.

This CPU was commissioned and approved by the AGA Institute Clinical Practice Updates Committee (CPUC) and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership and underwent internal peer review by the CPUC and external peer review through standard procedures of Clinical Gastroenterology and Hepatology. This expert commentary incorporates important and recently published studies in this field, and it reflects the experiences of the multidisciplinary group of authors composed of adult and pediatric gastroenterologists.

The use of intestinal ultrasound (IUS) in the clinical assessment of intestinal disorders remains in its infancy in North America. We present a case in which IUS was used as a complement to Crohn's disease treatment in a 19-year-old man. After endoscopy and diagnosis, IUS was employed alongside other investigations to elucidate the extent of disease activity. It allowed identification and monitoring of complications such as free fluid and mucosal inflammation. IUS provided a marker of disease activity, even during apparent clinical remission. This case demonstrates that IUS can enhance disease monitoring and inform direction of therapy.

Crohn's disease (CD) is characterized by discontinuous inflammation. Failure to identify skipping lesions of the terminal ileum (TI) or transmural changes can lead to incorrect management.

Eligible adult patients with CD undergoing ileo-colonoscopy and computed tomography enterography or magnetic resonance enterography within 6 months. We determined the prevalence of endoscopic skipping (normal ileum on colonoscopy but proximal small bowel inflammation on cross-sectional imaging), skip lesions (discontinuous inflammation along the gastrointestinal tract identified on cross-sectional imaging), structuring, and penetrating complications.

Among 202 patients, 45 (22.3%) had endoscopic skipping proximal to TI intubation. Fifty patients (24.5%) had small bowel skip lesions, primarily in the ileum. Strictures were identified in 34 patients (16.8%) through both imaging and ileo-colonoscopy, in 21 patients (10.4%) solely through cross-sectional imaging, and in 3 patients (1.5%) solely through ileo-colonoscopy. Approximately 36.2% of stricturing cases would be missed without cross-sectional imaging. Penetrating complications, including abscesses (2.5%) and various fistula types (4.9%), were detected in 15 (7.4%) patients.

Ileo-colonoscopy missed detection of active CD in approximately one-fifth of cases due to more proximal disease location. Stricturing disease might be missed in more than a third of cases if cross-sectional imaging is not performed.

Intestinal ultrasound (IUS) is increasingly used to assess Crohn's disease (CD) activity in clinical practice. However, application in clinical trials has been limited by heterogeneous scoring methods and concerns about reliability. We aimed to determine the inter- and intra-rater reliability of locally and centrally read IUS parameters for evaluating CD using prospectively performed scans.

Twenty-four participants with CD and 6 gastroenterologists participated in a 2-day workshop where each participant underwent 6 IUS scans in total. Eight IUS parameters (bowel wall thickness [BWT], bowel wall stratification [BWS], color Doppler signal [CDS], inflammatory mesenteric fat [i-fat], submucosal prominence, submucosal layer thickness, haustra coli/peristalsis, and affected segment length) and an overall measure of sonographic disease activity were blindly assessed by the 6 local readers and 4 central gastroenterologist-sonographers. Reliability was quantified using intraclass correlation coefficients (ICCs). Institutional review board approval was granted for this study (12938).

Five IUS parameters demonstrated at least moderate (ICC ≥0.41) inter- and intra-rater reliability when local and central reading was performed (BWT, CDS, i-fat, submucosal prominence, and affected segment length). Reliability was generally better with central, in distinction to local, reading. ICCs for BWS and i-fat were highest when evaluated as binary outcomes. Sensitivity analyses demonstrated that IUS parameters are most reliable when evaluated in the worst affected segment. Fair reliability was observed when local readers identified the worst affected segment.

Local and central reading of IUS demonstrated at least moderate inter- and intra-rater reliability for several parameters. This study supports refining existing activity indices and incorporating IUS central reading into clinical trials.

Perianal fistulas pose dual challenges to Crohn's disease (CD) patients. Low patient compliance due to the complexity of existing examination methods plagues the treatment and follow-up management of perianal CD.

To determine the accuracy of endoanal ultrasound (EUS) and shear wave elastography (SWE) for evaluating perianal fistulizing CD (PFCD) activity.

This was a retrospective cohort study. A total of 67 patients from August 2022 to December 2023 diagnosed with CD were divided into three groups: Non-anal fistula group (n = 23), low-activity perianal fistulas [n = 19, perianal disease activity index (PDAI) ≤ 4], high-activity perianal fistulas (n = 25, PDAI > 4) based on the PDAI. All patients underwent assessments including EUS + SWE, pelvic magnetic resonance [pelvic magnetic resonance imaging (MRI)], C-reactive protein, fecal calprotectin, CD activity index, PDAI.

The percentage of fistulas indicated by pelvic MRI and EUS was consistent at 82%, and there was good consistency in the classification of perianal fistulas (Kappa = 0.752, P < 0.001). Significant differences were observed in the blood flow Limberg score (χ 2 = 8.903, P < 0.05) and shear wave velocity (t = 2.467, P < 0.05) between group 2 and 3. Shear wave velocity showed a strong negative correlation with magnetic resonance novel index for fistula imaging in CD (Magnifi-CD) score (r = -0.676, P < 0.001), a weak negative correlation with the PDAI score (r = -0.386, P < 0.05), and a weak correlation between the Limberg score and the PDAI score (r = 0.368, P < 0.05).

EUS combined with SWE offers a superior method for detecting and quantitating the activity of perianal fistulas in CD patients. It may be the ideal tool to assess PFCD activity objectively for management strategies.

Crohn's disease (CD) is a chronic inflammatory disease of the digestive tract with unknown etiology. It follows a relapse-remission pattern, making disease activity assessment crucial for treatment. Our study aims to evaluate the diagnostic accuracy of various imaging modalities and to validate and compare the International Bowel Ultrasound Segmental Activity Score (IBUS-SAS), the multidetector computed tomography enterography score (MDCTEs), and the simplified endoscopic activity score for Crohn's disease (SES-CD).

We assessed diagnostic performance using the CD Activity Index (CDAI). We first categorized patients into remission and active groups. For those in the active stage, we further categorized them into mild/moderate and severe activity groups. We used Spearman rank correlation to evaluate the relationships among IBUS-SAS, bowel wall thickness (BWT), Color Doppler imaging signal (CDS), inflammatory fat (i-fat), bowel wall stratification (BWS), and clinical inflammatory indicators.

A total of 103 CD patients were evaluated. The IBUS-SAS cut-off for remission and activity was 23.8, with an AUC of 0.923, sensitivity of 91.4%, and specificity of 84.8%. The SES-CD had an AUC of 0.801, sensitivity of 62.9%, and specificity of 84.4% at a cut-off of 4.5. The MDCTEs showed an AUC of 0.855, sensitivity of 77.1%, and specificity of 75.8% for a cut-off of 6.5. The Delong test revealed significant differences in diagnostic efficacy when comparing IBUS-SAS to SES-CD and IBUS-SAS to MDCTEs. In the group of mild or moderate-to-severe active, the IBUS-SAS had an AUC of 0.925, sensitivity of 83.7%, and specificity of 88.9% at a cut-off of 40. The SES-CD exhibited an AUC of 0.850, sensitivity of 90.7%, and specificity of 70.4% at a cut-off of 8.5. MDCTEs showed an AUC of 0.909, sensitivity of 83.7%, and specificity of 85.2% at a cut-off of 8.5. During Delong test, the IBUS-SAS, MDCTEs, and SES-CD showed no significant differences in assessing moderate-to-severe activity. Both IBUS-SAS and ultrasound parameters correlated with certain serum indicators (p < 0.05), although only weakly to moderately (all r < 0.5).

The IBUS-SAS, MDCTEs and SES-CD can evaluate disease remission/active and mild/moderate-to-severe active in CD, and IBUS-SAS offers the potential to precisely define CD activity.

STRIDE-II recommends early biomarker targets for treatment optimization to achieve treat-to-target [T2T] endoscopic remission [ER] in Crohn's disease [CD]. The predictive capabilities of intestinal ultrasound [IUS] for T2T ER remain unknown. We aimed to evaluate IUS response to predict ER in children with CD.

This was a prospective longitudinal cohort study of children with ileal [TI] CD initiating biologic therapy undergoing IUS, clinical disease activity, and C-reactive protein [CRP] assessments at baseline, week 8, 6 months, and T2T within 1 year. The primary outcome was the accuracy of optimal cut-points to predict TI ER [SES-CD ≤ 2] for change in bowel wall thickness [BWT] on IUS from baseline to week 8, and BWT at week 8. Area under the receiver operating curve [AUROC] analysis was performed and univariate analysis tested associations.

In total, 44 children (median age 13 [IQR 12-17] years, 29 [66%] biologic naïve) were included, and 29 [66%] achieved ER. A ≥18% decrease in TI BWT at week 8 predicted ER with an AUROC of 0.99 [95% CI 0.98-1.00], 100% sensitivity, 93% specificity, 97% positive predictive value, and 100% negative predictive value, superior to a ≥46% decrease in PCDAI (AUROC 0.67 [95% CI 0.49-0.84]) and ≥84% decrease in CRP (AUROC 0.49 [95% CI 0.31-0.67]) at week 8.

Early change in TI BWT on IUS is highly predictive of ER in children with CD and superior to symptoms and CRP. Our findings suggest that IUS could be used for treatment optimization and tight control to guide T2T strategies.