Ultrasound remission after biologic induction and long-term endoscopic remission in Crohn's disease: a prospective cohort study

Intestinal ultrasound in Crohn’s disease: A systematic review of its role in diagnosis, monitoring, and treatment response

BACKGROUND

Intestinal ultrasound (IUS) has gained prominence as a safe, non-invasive imaging technique for managing Crohn’s disease (CD), offering real-time evaluation without radiation exposure.

AIM

To systematically review the role of IUS in diagnosing, monitoring disease progression, assessing treatment response, and managing complications in CD.

METHODS

A literature search of PubMed and Embase databases was conducted, identifying 207 original research articles published between 1953 and June 2024. The review focused on diagnostic accuracy, disease monitoring, therapeutic utility, and advancements in IUS applications.

RESULTS

IUS has shown high diagnostic accuracy for detecting inflammation, particularly in the ileum and colon, with limitations in jejunal and rectal regions. It is effective in assessing disease activity using parameters like bowel wall thickness (BWT) and vascularity and correlates well with endoscopy and magnetic resonance enterography. IUS can predict early response to biologics, with reductions in BWT serving as an important marker. In known CD, IUS influences clinical decisions during remission, flares, and therapy evaluations. It reliably detects strictures, fistulas, and therapy-related complications. Small intestinal contrast ultrasound (SICUS) can improve the detection of strictures particularly proximal ones. Techniques such as CE-IUS and elastography enhance stricture characterization but require further validation. IUS is also useful in special scenarios like perianal fistulas, pregnancy, post-operative CD, and guiding endoscopic therapy.

CONCLUSION

IUS is a patient-friendly, cost-effective imaging tool that significantly impacts CD management across various stages. Its integration into clinical practice supports early diagnosis, disease monitoring, and therapeutic adjustments. Further studies are warranted to refine advanced techniques and standardize its application for broader use.

A comparison between the Bowel Ultrasound Score and International Bowel Ultrasound Segmental Activity Score based on ileocolonoscopy in patients with Crohn's disease

BACKGROUND AND AIM

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).

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Transmural Healing Assessed by Combination of Fecal Calprotectin and Intestinal Ultrasonography Is Associated With Reduced Risk of Bowel Damage Progression in Patients With Crohn's Disease

BACKGROUND

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.

METHODS

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).

RESULTS

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).

CONCLUSIONS

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.

Epidemiology, pathogenesis, diagnosis, and treatment of inflammatory bowel disease: Insights from the past two years

ABSTRACT

Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, is a chronic inflammation of the gastrointestinal tract with unknown etiology. The cause of IBD is widely considered multifactorial, with prevailing hypotheses suggesting that the microbiome and various environmental factors contribute to inappropriate activation of the mucosal immune system in genetically susceptible individuals. Although the incidence of IBD has stabilized in Western countries, it is rapidly increasing in newly industrialized countries, particularly China, making IBD a global disease. Significant changes in multiple biomarkers before IBD diagnosis during the preclinical phase provide opportunities for earlier diagnosis and intervention. Advances in technology have driven the development of telemonitoring tools, such as home-testing kits for fecal calprotectin, serum cytokines, and therapeutic drug concentrations, as well as wearable devices for testing sweat cytokines and heart rate variability. These tools enable real-time disease activity assessment and timely treatment strategy adjustments. A wide range of novel drugs for IBD, including interleukin-23 inhibitors (mirikizumab, risankizumab, and guselkumab) and small-molecule drugs (etrasimod and upadacitinib), have been introduced in the past few years. Despite these advancements, approximately one-third of patients remain primary non-responders to the initial treatment, and half eventually lose response over time. Precision medicine integrating multi-omics data, advanced combination therapy, and complementary approaches, including stem cell transplantation, psychological therapies, neuromodulation, and gut microbiome modulation therapy, may offer solutions to break through the therapeutic ceiling.

Intestinal ultrasound as a prognostic tool in new-onset ulcerative colitis-a Copenhagen IBD Cohort Study

BACKGROUND AND AIMS

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Accuracy of superb microvascular imaging (SMI) in predicting endoscopic Crohn's disease activity

BACKGROUND

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.

AIMS

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

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Superb Microvascular Imaging Is Superior to Doppler Imaging in Ruling Out Ulcerative Colitis Disease Activity

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Understanding the learning curve of intestinal ultrasound in inflammatory bowel disease: A comparative study between novice, regular and expert

BACKGROUND

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.

AIMS

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Systematic review on definitions of intestinal ultrasound treatment response and remission in inflammatory bowel disease

BACKGROUND

Intestinal ultrasound (IUS) is emerging as a valuable tool to assess treatment response in inflammatory bowel disease (IBD) clinical trials. This study details how IUS defines response and remission to evaluate treatment efficacy in IBD patients.

METHODS

We conducted a comprehensive search of studies from 1984 to March 31, 2024, focusing on IUS use in assessing treatment efficacy in IBD.

RESULTS

A total of 51 studies were included: 31 on Crohn's disease (CD), 12 on ulcerative colitis (UC) and 8 on IBD. Ileocolonoscopy was used as a reference standard in 53% of studies. IUS-defined response was reported in 47% of studies, with the majority (71%) using changes in bowel wall thickness (BWT) and color Doppler signals (CDS) as key indicators. IUS-defined remission was reported in 53% of studies, primarily using normalization of BWT to <3 mm and CDS to grades 0 or 1 as criteria. Ultrasonographic activity scores were used in 16% of studies, including the Bowel Ultrasound Score (BUSS) in two CD studies, the International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) in one CD study, and the Milan Ultrasound Criteria (MUC) in one UC study The remaining four studies used unvalidated scores without clear definitions of response or remission. Assessment times varied, most commonly at weeks 8-16, and at 6, 12, and 24 months.

CONCLUSIONS

This systematic review reveals significant variability in IUS definitions of response and remission in IBD, highlighting the need to standardize eligibility criteria and outcome measures for IUS in IBD clinical trials.

Advancing Therapeutic Targets in IBD: Emerging Goals and Precision Medicine Approaches

Inflammatory bowel diseases (IBD) including Crohn's disease (CD) and ulcerative colitis (UC) are chronic, relapsing conditions characterized by dysregulated immune responses and persistent intestinal inflammation. This review aims to examine new potential therapeutic targets in IBD starting from the STRIDE-II statements. Key targets now include clinical remission, endoscopic remission, and biomarker normalization (such as C-reactive protein and fecal calprotectin). Moreover, histologic remission, transmural remission, and in the future molecular targets are emerging as important indicators of sustained disease control. The treatment goals for inflammatory bowel disease are varied: to relieve symptoms, prevent permanent intestinal damage, promote inflammation remission, and minimize complications. Consequently, the therapeutic targets have evolved to become broader and more ambitious. Integrating these advanced therapeutic targets has the potential to redefine IBD management by promoting deeper disease control and improved patient outcomes. Further research is essential to validate these strategies and optimize their clinical implementation.

Crohn's disease management: translating STRIDE-II for UK clinical practice

Crohn's disease (CD) is a chronic inflammatory bowel disease (IBD) characterised by endoscopic inflammation, progressive bowel damage and gastrointestinal lesions. Although treatment strategies for CD have traditionally focused on a stepwise pharmacological approach to achieve clinical remission or symptom resolution, these treatment goals correlate poorly with disease activity. Thus, achieving full clinical remission and full endoscopic healing alone may be insufficient, as patients may remain at risk of inflammatory complications. Individualised 'treat-to-target' (T2T) pharmacological and treatment approaches represent a promising strategy for improving endoscopic remission and symptom resolution among patients with CD. The Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE) and STRIDE-II guidelines, launched in 2013 and later renewed, identified individualised targets for a T2T therapeutic approach for patients with IBD. These guidelines facilitate the individualisation of target treatment goals through evidence-based, long-term (health-related quality of life, absence of disability, endoscopic healing) and intermediate/short-term (abdominal pain, stool frequency, normalisation of biomarker levels) treatment targets, allowing patients and clinicians to consider the risk-to-benefit balance of goals and selected therapeutic strategies. This article aims to summarise the STRIDE-II guidelines and provide intellectual guidance for healthcare professionals to apply the STRIDE-II principles to current clinical practice in the United Kingdom (UK). Management recommendations for primary and secondary first-line non-responders are provided, along with suggestions for utilising the endoscopic outcomes scoring system in UK clinical practice.

Role of Intestinal Ultrasound for IBD Care: A Practical Approach

Intestinal ultrasound (IUS) has recently become the imaging technique of choice for patients with different types of intestinal inflammation. IUS has a high sensitivity, specificity, positive predictive value, and negative predictive value when diagnosing Crohn's disease or ulcerative colitis. Further, it is now the preferred imaging modality for routine IBD reevaluations because of its non-invasiveness, cost-effectiveness, availability (at least in Europe), and reproducibility in all age groups. However, the clinical success of IUS requires IUS training for doctors and technicians who perform IUS with a standardised description of ultrasound findings of the terminal ileum and entire colon. Complications such as abscess formation, fistulae, and stenosis can be detected by either conventional IUS or contrast-enhanced ultrasound (CEUS). Lately, several disease activity scores have been proposed for Crohn's disease, postoperative Crohn's disease, and ulcerative colitis both in adults (including elderly) and in children. IUS was successfully used in randomised clinical trials in order to measure the treatment response. Therefore, IUS now plays a central role in clinical decision making.