Quantitative contrast-enhanced ultrasound for monitoring vedolizumab therapy in inflammatory bowel disease patients: a pilot study

Role of intestinal ultrasound in ulcerative colitis: A systematic review

BACKGROUND

Intestinal ultrasound (IUS) is an emerging, non-invasive, and highly sensitive diagnostic tool in inflammatory bowel disease (IBD), including ulcerative colitis (UC). Despite its potential, its adoption in clinical practice is limited due to a lack of standardization and awareness.

AIM

To perform a comprehensive scoping review based on a systematic literature review on IUS in UC to inform current practice.

METHODS

Ninety-nine original articles about ultrasonography in UC were identified among 7608 citations searching PubMed and EMBASE databases for systematic review.

RESULTS

IUS can be useful as an initial diagnostic strategy in patients with suspected IBD/UC. In UC, IUS can predict endoscopic response, histologic healing, and steroid responsiveness in acute severe cases. IUS can predict response to biologics/small molecules (as early as 2 wk). IUS correlates well with ileo-colonoscopy, but IUS could miss rectal, jejunal, and upper GI lesions in suspected IBD and colon polyps or extra-intestinal manifestations in known IBD. IUS is useful in special situations (children, pregnancy, and postoperative Crohn's disease). Inter-observer agreement is acceptable and trained physicians have comparable diagnostic accuracy. Point-of-care ultrasound impacted management in 40%-60% of cases. Hand-held IUS has excellent agreement with conventional IUS.

CONCLUSION

IUS is a non-invasive, highly sensitive tool in the diagnosis and monitoring of UC, offering excellent patient satisfaction. Point-of-care ultrasound by IBD physicians can significantly impact clinical decision-making.

Novelties and Perspectives of Intestinal Ultrasound in the Personalised Management of Patients with Inflammatory Bowel Diseases-A Systematic Review

Inflammatory bowel diseases (IBDs) affect over 4.9 million individuals worldwide. Colonoscopy (CS) is the gold-standard technique for diagnosis. The remissive-recurrent pattern of evolution raises the need for non-invasive techniques to monitor disease activity. This review aims to present the advantages of intestinal ultrasound (IUS) in managing IBDs. Our search was conducted on the PubMed, Embase, and Cochrane (CENTRAL) databases, selecting original studies comparing IUS with other imaging and invasive monitoring methods. Our search yielded 8654 results, of which 107 met the inclusion criteria. Increased bowel wall thickness (BWT) and colour Doppler signal (CDS) are discriminative for disease activity. IUS can predict disease outcomes and detect response to treatment or postoperative recurrence. Contrast-enhanced ultrasound (CEUS) and elastography help differentiate fibrotic from inflammatory stenoses. The difficult rectal assessment limits the use of IUS in ulcerative colitis (UC). Transmural healing may develop as a therapeutic target as it is associated with better outcomes. Patients are compliant with this technique, and its results correlate well with CS and other imaging methods. In conclusion, IUS proves to be essential in assessing IBD activity and treatment response, predicting outcomes and detecting complications. CEUS and elastography are researched to improve the diagnostic values of IUS.

EFSUMB Technical Review - Update 2023: Dynamic Contrast-Enhanced Ultrasound (DCE-CEUS) for the Quantification of Tumor Perfusion

Dynamic contrast-enhanced ultrasound (DCE-US) is a technique to quantify tissue perfusion based on phase-specific enhancement after the injection of microbubble contrast agents for diagnostic ultrasound. The guidelines of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) published in 2004 and updated in 2008, 2011, and 2020 focused on the use of contrast-enhanced ultrasound (CEUS), including essential technical requirements, training, investigational procedures and steps, guidance regarding image interpretation, established and recommended clinical indications, and safety considerations. However, the quantification of phase-specific enhancement patterns acquired with ultrasound contrast agents (UCAs) is not discussed here. The purpose of this EFSUMB Technical Review is to further establish a basis for the standardization of DCE-US focusing on treatment monitoring in oncology. It provides some recommendations and descriptions as to how to quantify dynamic ultrasound contrast enhancement, and technical explanations for the analysis of time-intensity curves (TICs). This update of the 2012 EFSUMB introduction to DCE-US includes clinical aspects for data collection, analysis, and interpretation that have emerged from recent studies. The current study not only aims to support future work in this research field but also to facilitate a transition to clinical routine use of DCE-US.

Dynamic contrast enhanced ultrasound in gastrointestinal diseases: A current trend or an indispensable tool?

Contrast enhanced ultrasound (CEUS) has been widely implemented in clinical practice because of the enormous quantity of information it provides, along with its low cost, reproducibility, minimal invasiveness, and safety of the second-generation ultrasound contrast agents. To overcome the limitation of CEUS given by the subjective evaluation of the contrast enhancement behaviour, quantitative analysis of contrast kinetics with generation of time-intensity curves has been introduced in recent years. The quantification of perfusion parameters [named as dynamic-CEUS (D-CEUS)] has several applications in gastrointestinal neoplastic and inflammatory disorders. However, the limited availability of large studies and the heterogeneity of the technologies employed have precluded the standardisation of D-CEUS, which potentially represents a valuable tool for clinical practice in management of gastrointestinal diseases. In this article, we reviewed the evidence exploring the application of D-CEUS in gastrointestinal diseases, with a special focus on liver, pancreas, and inflammatory bowel diseases.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Intestinal Ultrasound in Inflammatory Bowel Disease: A Valuable and Increasingly Important Tool

Background

Intestinal ultrasound is emerging as a non-invasive tool for monitoring disease activity in inflammatory bowel disease patients due to its low cost, excellent safety profile, and availability. Herein, we comprehensively review the role of intestinal ultrasound in the management of these patients.

Summary

Intestinal ultrasound has a good accuracy in the diagnosis of Crohn's disease, as well as in the assessment of disease activity, extent, and evaluating disease-related complications, namely strictures, fistulae, and abscesses. Even though not fully validated, several scores have been developed to assess disease activity using ultrasound. Importantly, intestinal ultrasound can also be used to assess response to treatment. Changes in ultrasonographic parameters are observed as early as 4 weeks after treatment initiation and persist during short- and long-term follow-up. Additionally, Crohn's disease patients with no ultrasound improvement seem to be at a higher risk of therapy intensification, need for steroids, hospitalisation, or even surgery. Similarly to Crohn's disease, intestinal ultrasound has a good performance in the diagnosis, activity, and disease extent assessment in ulcerative colitis patients. In fact, in patients with severe acute colitis, higher bowel wall thickness at admission is associated with the need for salvage therapy and the absence of a significant decrease in this parameter may predict the need for colectomy. Short-term data also evidence the role of intestinal ultrasound in evaluating therapy response, with ultrasound changes observed after 2 weeks of treatment and significant improvement after 12 weeks of follow-up in ulcerative colitis.

Key Messages

Intestinal ultrasound is a valuable tool to assess disease activity and complications, and to monitor response to therapy. Even though longer prospective data are warranted, intestinal ultrasound may lead to a change in the paradigm of inflammatory bowel disease management as it can be used in a point-of-care setting, enabling earlier intervention if needed.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Contrast-enhanced ultrasound of the pediatric bowel

Contrast-enhanced ultrasound (CEUS) has emerged as a valuable modality for bowel imaging in adults and children. CEUS enables visualization of the perfusion of the bowel wall and of the associated mesentery in healthy and disease states. In addition, CEUS images can be used to make quantitative measurements of contrast kinetics, allowing for objective assessment of bowel wall enhancement. Bowel CEUS is commonly applied to evaluate inflammatory bowel disease and to monitor treatment response. It has also been applied to evaluate necrotizing enterocolitis, intussusception, appendicitis and epiploic appendagitis, although experience with these applications is more limited. In this review article, we present the current experience using CEUS to evaluate the pediatric bowel with emphasis on inflammatory bowel disease, extrapolating the established experience from adult studies. We also discuss emerging applications of CEUS as an adjunct or problem-solving tool for evaluating bowel perfusion.

Contrast-enhanced US in Pediatric Patients: Overview of Bowel Applications

Contrast material-enhanced US is a technique that is approved by the U.S. Food and Drug Administration for the characterization of liver lesions and intravesicular applications in children; however, contrast-enhanced US has several other pediatric applications in clinical practice. The most common application is for patients with inflammatory bowel disease (IBD). Contrast-enhanced US can be used to diagnose IBD, distinguish regions of active or chronic inflammation of the bowel wall, and evaluate associated complications such as abscesses, fistulas, and strictures. Dynamic contrast material evaluation provides qualitative and quantitative information about mural and mesenteric blood flow, which is essential in the determination of disease activity in these patients. It also has the potential to provide a means of monitoring the response to therapy beyond endoscopy or MR enterography. In addition to its use for IBD, contrast-enhanced US can be used to assess for bowel perfusion when problem solving in patients with necrotizing enterocolitis, neonatal bowel infarction, or intussusception. It is a useful imaging technique to fortify diagnoses that may otherwise be indeterminate, such as appendicitis, epiploic appendagitis, intraluminal bowel masses, and complex cysts. Finally, innovative applications such as shear-wave elastography have the potential to provide information about the stiffness of the bowel wall. Online supplemental material is available for this article. ©RSNA, 2020 See discussion on this article by Watson and Humphries.

Systematic Review: Clinical Utility of Gastrointestinal Ultrasound in the Diagnosis, Assessment and Management of Patients With Ulcerative Colitis

BACKGROUND AND AIMS

Gastrointestinal ultrasound is useful in the assessment of patients with Crohn's disease, but its application in ulcerative colitis [UC] is less well established. Here we systematically review the role of gastrointestinal ultrasound in patients with UC.

METHODS

Searches of the PUBMED and EMBASE databases were performed with the following search strategy: [ultrasound OR sonography] AND [intestinal OR bowel] AND [ulcerative colitis OR inflammatory bowel disease]. The final search was performed in August 2019.

RESULTS

Of 6769 studies identified in the search with a further two studies found from other sources, 50 studies met the inclusion criteria. Increased bowel wall thickness and detection of increased blood flow by colour Doppler were the most often applied criteria for defining disease activity and distribution. When compared with other reference investigations, gastrointestinal ultrasound accurately determined disease extent, severity and response to medical therapy. While further information can be obtained from haemodynamic measurements of the abdominal vessels and contrast-enhanced ultrasound, their clinical value was uncertain. Likewise, hydrocolonic sonography has few advantages over standard gastrointestinal ultrasound examination. Of several scoring systems proposed, there is disparity between the measures and a general lack of validation. There has been limited application of gastrointestinal ultrasound in acute severe ulcerative colitis with toxic megacolon, and, while performing well in children, normal limits differ from those in adults.

CONCLUSION

Current evidence indicates that gastrointestinal ultrasound has utility in the non-invasive assessment of patients with UC. Continued advances in technology with better image resolution, validation of scoring systems and application at the point of care by gastroenterologists are likely to contribute to increased use of gastrointestinal ultrasound in routine clinical practice.