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

Role of noncontrast enhanced abdominal ultrasound in the diagnostic assessment of pediatric inflammatory bowel disease

OBJECTIVES

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Intestinal ultrasound at diagnosis of pediatric inflammatory bowel disease compared to endoscopy

OBJECTIVES

Intestinal ultrasound (IU) has emerged as an alternative to detect bowel wall inflammation. The aim of this study was to compare IU findings to clinical disease, fecal calprotectin (FC), and endoscopic findings in newly diagnosed pediatric inflammatory bowel disease (IBD) patients.

METHODS

This study was a 1-year, single-center, prospective study. Any pediatric patient undergoing colonoscopy could be recruited. Following ileo-colonoscopy, subjects were divided into two groups: patients diagnosed with IBD and patients without IBD. Participants had an IU within 1 month. Endoscopists and radiologists were blinded to each other. The IU findings were compared with clinical disease activity, FC, and endoscopic findings.

RESULTS

A total of 50 subjects were enrolled in the study; 29 (58%) were females, median age was 13.5 years, and 25 (50%) were diagnosed with IBD. IU sensitivity was 76%, specificity 84%, positive predictive value (PPV) 83%, and negative predictive value (NPV) 78%. For detection of moderate to severe disease, sensitivity, specificity, PPV, and NPV were 91.3%, 86.21%, 84%, and 92.6%, respectively. A significant correlation was noted between IU and FC, Mayo score, and Simple Endoscopic Score (0.513, 0.565, and 0.731, respectively). Pediatric Ulcerative Colitis Activity Index and Pediatric Crohn's Disease Activity Index scores had Pearson correlations of 0.070 and -0.159, respectively.

CONCLUSIONS

IU can be considered a screening tool for pediatric IBD. It has reasonable sensitivity, specificity, PPV, and NPV, particularly for moderate-to-severe disease. The severity noted on IU correlated with FC and endoscopic disease activity but did not correlate with clinical disease activity.

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.

Magnetic Resonance Enterography and Intestinal Ultrasound for the Assessment and Monitoring of Crohn's 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.

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.

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.

Use of imaging modalities for decision-making in inflammatory bowel disease

Cross-sectional magnetic resonance enterography (MRE) and intestinal ultrasonography (IUS) provide valuable and noninvasive information to accurately assess disease activity, severity, and extent; detect complications; and monitor the response to treatment, as well as predict the postoperative recurrence of Crohn's disease and a negative disease course. Therefore, both imaging modalities are emerging as pivotal diagnostic tools to achieve the emerging therapeutic target of transmural healing associated with better disease outcomes. Despite its numerous potential advantages over endoscopy and even MRE and its good availability, IUS is still widely underused to monitor and manage inflammatory bowel disease (IBD) patients and help in making clinical decisions in routine practice. This situation is clearly due to the absence of validated, reliable, and responsive indices, as well as the lack of trained gastroenterologists and radiologists, as IUS is a component of radiologist expertise in several countries but not yet integrated into the training program of gastroenterologists. However, there is an increasing body of evidence in the literature that IUS and MRE are both becoming essential imaging resources to help clinicians in making reliable decisions. Here, we discuss the up-to-date evidence about the usefulness and performance of cross-sectional imaging, focusing on the ability of bowel US and MRE to aid clinical decision-making for the optimal management and monitoring of IBD.

Point-of-care Ultrasound of the Gastrointestinal Tract

The widespread use of portable ultrasound scanners has promoted the concept of point of care ultrasound (POCUS), namely "ultrasound performed bedside and interpreted directly by the clinician." The purpose of this short review is to outline how POCUS can be used in patients with diseases of the gastrointestinal (GI) tract. POCUS is not a replacement for comprehensive ultrasound, but rather allows physicians immediate access to clinical imaging for rapid diagnosis and efficient work-up and treatment of the patients. There are many indications for doing POCUS of the GI tract, including abdominal pain, diarrhea, palpable masses, and to detect fluid or free air in the abdominal cavity. To improve the visibility of deeper parts of the abdomen, the graded compression technique with the scan head is useful. During POCUS, the operator should look for signs of severe pathology including target lesions, the pseudo-kidney sign, the onion sign, dilated bowel loops, gastric retention, free fluid, and free air, depending on the actual clinical problem. We conclude that POCUS of the GI tract is very useful to provide a rapid diagnosis in many clinical scenarios.

Tools for the Diagnosis and Management of Crohn's Disease

Numerous tools have emerged over recent decades to aid in the increasingly complex management of patients with Crohn's disease (CD) beyond endoscopy, including video capsule endoscopy, magnetic resonance enterography, computed tomography enterography, a variety of biomarkers, and even wearable biosensors and smartphone applications. These tools have allowed for a more sophisticated and less invasive complementary approach to the evaluation of disease activity and treatment response in patients with CD. This article details the characteristics, practical application, and limitations of these various modalities and discusses how updated guidelines are now incorporating many of them into a treat-to-target strategy.

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.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

WSES-AAST guidelines: management of inflammatory bowel disease in the emergency setting

BACKGROUND

Despite the current therapeutic options for the treatment of inflammatory bowel disease, surgery is still frequently required in the emergency setting, although the number of cases performed seems to have decreased in recent years. The World Society of Emergency Surgery decided to debate in a consensus conference of experts, the main pertinent issues around the management of inflammatory bowel disease in the emergent situation, with the need to provide focused guidelines for acute care and emergency surgeons.

METHOD

A group of experienced surgeons and gastroenterologists were nominated to develop the topics assigned and answer the questions addressed by the Steering Committee of the project. Each expert followed a precise analysis and grading of the studies selected for review. Statements and recommendations were discussed and voted at the Consensus Conference of the 6th World Society of Emergency Surgery held in Nijmegen (The Netherlands) in June 2019.

CONCLUSIONS

Complicated inflammatory bowel disease requires a multidisciplinary approach because of the complexity of this patient group and disease spectrum in the emergency setting, with the aim of obtaining safe surgery with good functional outcomes and a decreasing stoma rate where appropriate.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Systematic Review: Gastrointestinal Ultrasound Scoring Indices for Inflammatory Bowel Disease

BACKGROUND AND AIMS

Serial measurements of luminal disease activity may facilitate inflammatory bowel disease management. Gastrointestinal ultrasound is an easily performed, non-invasive alternative to other assessment modes. However, its widespread use is limited by concerns regarding validity, reliability, and responsiveness. We systematically identified ultrasound scoring indices used to evaluate inflammatory bowel disease activity and examine their operating characteristics.

METHODS

Electronic databases were searched from inception to June 14, 2019 using pre-defined terms. Studies that reported on gastrointestinal ultrasound index operating properties in an inflammatory bowel disease population were eligible for inclusion. Study characteristics, index components, and operating property data [ie, validity, reliability, responsiveness, sensitivity, specificity, accuracy, positive predictive value, and negative predictive value] were extracted. The QUADAS-2 tool was used to examine study-level risk of bias.

RESULTS

Of the 2610 studies identified, 26 studies reporting on 21 ultrasound indices were included. The most common index components included bowel wall thickness, colour Doppler imaging, and bowel wall stratification. The correlation between ultrasound indices and references standards ranged r = 0.62-0.95 and k = 0.40-0.96. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive values ranged 39-100%, 63-100%, 73-100%, 57-100%, and 40-100%, respectively. Reliability and responsiveness data were limited. Most [92%, 24/26] studies received at least one unclear or high risk of bias rating.

CONCLUSIONS

Several gastrointestinal ultrasound indices for use in inflammatory bowel disease have been developed. Future research should focus on fully validating existing or novel gastrointestinal ultrasound scoring instruments for assessment of Crohn's disease and ulcerative colitis.