The knowledge and skills needed to perform intestinal ultrasound for inflammatory bowel diseases-an international Delphi consensus survey

Small bowel ultrasound: friend or foe?

PURPOSE OF REVIEW

Crohn's disease (CD), requires accurate diagnosis and regular monitoring to manage disease activity, prevent complications, and improve outcomes. Intestinal ultrasound (IUS) has emerged as a noninvasive, real-time imaging modality, offering a valuable alternative to traditional diagnostic techniques such as magnetic resonance enterography (MRE), endoscopy and capsule endoscopy (CE). This review examines recent advances in IUS for the diagnosis and monitoring of small bowel CD, with a focus on its applications, benefits, and limitations.

RECENT FINDINGS

Recent studies have demonstrated that IUS provides high sensitivity and specificity in detecting key markers of disease activity, including bowel wall thickness (BWT), bowel wall flow (BWF), and bowel wall stratification (BWS). Advances in IUS techniques, such as elastography and contrast-enhanced ultrasound (CEUS), have expanded its diagnostic and prognostic capabilities, potentially enabling differentiation between inflammation and fibrosis. However, challenges remain, including operator dependency, variability in scoring systems, and reduced sensitivity for superficial mucosal abnormalities. Efforts to standardize parameters and improve training have shown promise in addressing these limitations.

SUMMARY

IUS is a critical complementary tool for assessing disease activity, transmural healing, and postoperative recurrence in small bowel CD. Its noninvasiveness, cost-effectiveness, and real time assessment make it well suited for routine clinical use. Nonetheless, further multicentre studies are needed to validate scoring systems, optimize integration with other modalities, and improve consistency across clinical settings. IUS holds significant potential for advancing personalized care in small bowel CD, though ongoing research is required to refine its applications and maximize its clinical utility.

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.

PET/MRI in paediatric inflammatory bowel disease - a prospective accuracy study

Cross-sectional imaging supplements endoscopy in detecting disease manifestations in inflammatory bowel diseases (IBD). This study aimed to evaluate the accuracy of PET/MRI in a paediatric population suspected of IBD. This prospective study consecutively included patients aged 8-17 years under diagnostic evaluation for IBD. Forty-three patients underwent a PET/MRI scan and subsequent ileocolonoscopy, of whom 26 patients diagnosed with IBD participated in a follow-up scan, hereof 19 with Crohn's disease (CD), five with Ulcerative colitis and two with unclassified IBD. The results of PET alone, MRI alone, and PET/MRI combined were compared to a reference standard of endoscopy and histopathology. Of the 208 intestinal segments analysed, 109 showed inflammation, and 99 had no inflammation. In the per-segment analysis PET had a sensitivity of 0.83 (95% CI 0.73-0.93), specificity of 0.59 (95% CI 0.47-0.71), and area under the receiver operating characteristic curve (AUROC) of 0.73 (95% CI 0.67-0.80). MRI had a sensitivity of 0.52 (95% CI 0.41-0.64), specificity 0.89 (95% CI 0.82-0.96), and AUROC of 0.72 (95% CI 0.66-0.77). PET/MRI had a sensitivity of 0.83 (95% CI 0.74-0.94), specificity of 0.57 (95% CI 0.44-0.69), and AUROC of 0.77 (95% CI 0.71-0.84). At follow-up, PET and MRI scores decreased, and the change in MRI was able to identify patients with a clinical response. The accuracy of the PET/MRI scan in detecting inflammation in the terminal ileum and colon was moderate and not superior to either modality alone. With technological advances and combined reading, PET/MRI may still be valuable in selected cases.

Variables for reporting studies on extended - focused assessment with sonography for trauma (E-FAST): An international delphi consensus study

BACKGROUND

The Extended Focused Assessment with Sonography for Trauma (E-FAST) is a diagnostic ultrasound technique used in hospital and pre-hospital settings for patients with torso trauma. While E-FAST is common in emergency departments, its pre-hospital use is less routine. This study aims to establish a set of variables for designing studies on pre-hospital E-FAST through a Delphi consensus process involving international experts.

METHODS

A Delphi consensus process was utilized, involving four rounds of e-mail to the experts. The experts proposed variables for each category, assessed them using a 5-point Likert scale, and voted on whether they should be included in the final template.

RESULTS

Out of 14 invited experts, 9 participated in the study. In total, the experts proposed 247 variables. After four rounds, a final list of 32 variables was approved by all experts. These variables related to the system, patient, process, training, imaging, outcome, and others.

CONCLUSIONS

This Delphi consensus study presents a list of 32 variables for future research studies concerning the use of E-FAST ultrasound in pre-hospital settings. The results of this study are significant as they provide a standardized set of variables that will facilitate the comparison of data obtained from various studies. This will ultimately contribute to the advancement of pre-hospital E-FAST research and practice.

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.

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.

Diagnosis and management of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic and relapsing immune-mediated disease of the gastrointestinal tract with a gradually increasing global incidence and prevalence. A prolonged course of IBD leads to a decline in patient quality of life and the creation of a substantial economic burden on society. Owing to the lack of specific diagnostic markers, the diagnosis of IBD still needs a gold standard based on a combination of clinical manifestations, imaging, laboratory, and endoscopic results. Accordingly, the current goals of IBD treatment are to alleviate clinical symptoms and reduce recurrence rates. Therefore, it is imperative to develop a standard set of procedures to diagnose and treat IBD. In this review, we summarize prominent and emerging studies, outline classical and contemporary approaches to diagnosing and managing IBD, and integrate multiple guidelines. Furthermore, we propose the possibility of establishing an early and comprehensive diagnostic workflow and personalized management strategy in the future. We aim to enhance the quality and standardization of diagnostic and treatment procedures for IBD.

The role of intestinal ultrasound with colour Doppler in predicting the response to biologic therapy in inflammatory bowel disease patients

Introduction

Inflammatory bowel disease patients are exposed to frequent procedures and hospital admissions as well as recurrent need for radiological examinations with a high risk of exposure to radiation and contrast.

Aim

Our objective was to evaluate the role of a combination of both intestinal ultrasound (IUS) and colour Doppler with different parameters for monitoring changes in inflammation over time and to reveal their potential role in the assessment of response to biologic therapy in inflammatory bowel disease (IBD) patients.

Material and methods

Before the induction of biological therapy, IUS together with colour Doppler of the intestine was conducted. Response to therapy was defined following the international guidelines.

Results

A total of 45 patients with histopathological diagnosis of IBD were enrolled in the study. All patients received biological therapy and were assessed for response after 3 months. Out of those patients, 34 (75.6%) had good response while 11 (24.4%) failed to respond to the treatment. Our findings point to a strong association between bowel wall thickening (BWT) and serum albumin, erythrocyte sedimentation rate (ESR), and c-reactive protein (CRP). The overall sensitivity of IUS varied from 54 to 93% when evaluating bowel affection, with a specificity of 97-100%, in comparison to our results, which showed a sensitivity of 64-74% and specificity of 79-82%. Doppler parameters could predict the response to the biologic therapy in IBD patients.

Conclusions

Intestinal ultrasound and colour Doppler provide a safe, non-invasive way to monitor changes in inflammation and blood flow in the digestive tract.

Current and Novel Uses of Intestinal Ultrasound in Inflammatory Bowel Disease

Intestinal ultrasound (IUS) is a patient-centric, noninvasive, real-time, point-of-care tool with the capability to aid in diagnosis and monitoring of disease activity in both Crohn's disease and ulcerative colitis without the need for bowel preparation. IUS can be used as a tool for precision monitoring of inflammatory bowel disease (IBD) treatment response. IUS as a cross-sectional imaging tool is as accurate as magnetic resonance enterography (MRE) for assessing the ileum and is more accurate than MRE for colonic assessment proximal to the rectum. Multiple simple ultrasound-based scoring systems have been internally validated with endoscopy in both Crohn's disease and ulcerative colitis, and changes in IUS parameters can be seen as early as 2 weeks after treatment initiation. IUS also plays a unique role in IBD activity monitoring of patients in whom avoidance of invasive testing is paramount, such as children and pregnant patients. Novel uses go beyond monitoring activity, with potential use of elastography to measure bowel wall stiffness to detect fibrosis and bowel damage for enhanced decision-making. Ultimately, IUS is likely to expand in the United States, facilitated by accessible expert training, access to equipment, and the development of a reimbursement model. This article provides a comprehensive review of the current and novel uses of IUS in IBD.

Intestinal ultrasound in patients with suspected Crohn's disease - results of a prospective evaluation by trainees

BACKGROUND AND AIMS

Intestinal ultrasound (IUS) performed by experts is a valuable tool for the diagnostic work-up and monitoring of Crohn's disease (CD). However, concern about insufficient training and perceived high inter-observer variability limit the adoption of IUS in CD. We examined the diagnostic accuracy of trainee-performed IUS in patients with suspected CD.

METHOD

Patients recruited to a prospective trial investigating the diagnostic accuracy of magnetic resonance enterocolonography (MREC) in patients with clinically suspected CD underwent IUS performed by trainees. The primary end-point was IUS per-patient sensitivity and specificity for ileocolonic CD determined by ileocolonoscopy.

RESULTS

129 patients with clinically suspected CD and a complete IC and IUS were included in the analysis. IUS detected signs of CD in 49 cases (small bowel 31, colon 15, small bowel, and colon 3). The sensitivity and specificity for detection of ileocolonic CD by trainee performed IUS improved during the first to the second half of the study period from 57.1% (CI 34.0-78.2) to 73.1% (CI 52.2-88.4) and 76.5% (CI 58.8-89.3) to 89.7% (CI 72.6-97.8). The overall sensitivity and specificity of diagnosing CD with IUS were 65.4% (CI 50.9-78.0) and 80.5% (CI 69.9-88.7). There was no difference in diagnostic performance between IUS and MREC for the detection of CD.

CONCLUSION

Trainees improved during the study, and IUS performance in disease detection corresponded to expert-evaluated MREC.Registered at ClinicalTrials.gov (NCT03134586).

The use of ultrasound in colonic and perianal diseases

PURPOSE OF REVIEW

To revise recent literature findings regarding the use of ultrasound in colonic and perianal diseases by focusing particularly on its feasibility in inflammatory bowel diseases (IBD), colorectal neoplastic lesions, and perineal diseases, with further highlight on interventional capabilities.

RECENT FINDINGS

Treat-to-target approach in IBD raised an interest in intestinal ultrasound (IUS) for monitoring bowel activity considering its noninvasive nature, low costs, and well tolerability. New IUS indices have been developed with ever better methodologies and are at various stage of validation. A standardized over-the-wire technique for colonic US using a flexible overtube enables endoscopic ultrasound (EUS)-guided tissue sampling beyond the rectum, and forward-viewing radial-array echoendoscopes can assist identification of early neoplastic lesions in proximal colon. Intraoperative ultrasound and contrast-enhanced ultrasound carry an additional diagnostic value compared to conventional preoperative imaging modalities in detecting colorectal cancer liver metastases (CRLM).

SUMMARY

The feasibility of IUS in monitoring IBD activity is supported by growing evidence, but uniform IUS indices are still lacking. Recent advancements in EUS are expanding capabilities for determining depth of invasion of colorectal neoplasms, tissue sampling, and EUS-guided interventions to the entire colon. Ultrasonography can be a valuable tool in CRLM diagnostics as well.

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

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