Contrast-enhanced ultrasound in the differentiation between phlegmon and abscess in Crohn's disease and other abdominal conditions

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.

Diagnosis and Differentiation of Inflammatory Bowel Disease

Differentiating Crohn's disease from ulcerative colitis may be a diagnostic challenge for clinicians due to overlapping features. However, the correct diagnosis may guide treatment options and considerations regarding surgery. This study reviews the common components of diagnostic evaluation of inflammatory bowel disease. Additionally, this article provides a basis of understanding for the more complex aspects of the disease to be discussed in subsequent studies.

Operative Management of Inflammatory Bowel Disease in Children

Inflammatory bowel disease (IBD) encompasses a spectrum of chronic, idiopathic, and progressive inflammatory conditions of the gastrointestinal tract, with Crohn's disease and ulcerative colitis comprising the majority. Both conditions have distinct pathophysiological and clinical characteristics but share common immune-mediated mechanisms. Specific facets of IBD and its management in the pediatric population differ from adult parallels. This article explores the surgical treatments of pediatric IBD, focusing on indications for surgery and perioperative considerations.

Non-invasive monitoring of inflammatory bowel disease using intestinal ultrasound

BACKGROUND

Intestinal ultrasound (IUS) is a safe and effective way for the diagnosis and surveillance of patients with inflammatory bowel disease (IBD). It allows a noninvasive and reproducible follow-up for patients with IBD.

AIM

To compare the outcomes of colonoscopy and IUS in diagnosing and monitoring patients with IBD.

METHODS

A prospective study was conducted over a three-year period (January 2021 to April 2024) comparing endoscopic and IUS findings. A total of 101 patients were included in the study (68 with Crohn's disease and 33 with ulcerative colitis). All patients underwent both IUS and colonoscopy within a 10-day period.

RESULTS

The study found a strong correlation between bowel thickening on IUS and inflammatory activity (P = 0.004), IUS remission and endoscopic remission (P = 0.03), IUS and endoscopic location (P = 0.04), as well as IUS and computed tomography scan findings for collection diagnosis (P < 0.01).

CONCLUSION

The study's findings demonstrated excellent results for using IUS in the diagnosis and follow-up of IBD patients.

Unveiling the superior diagnostic efficacy of double-balloon endoscopy compared to small intestine dual-energy CT enterography in small bowel Crohn's disease

BACKGROUND

Dual-energy computed tomography enterography (DECTE) has significantly improved gastrointestinal imaging quality. Double-balloon endoscopy (DBE) has enabled comprehensive visualization of the small intestinal mucosa. This study aimed to assess the diagnostic efficacy of small-intestine DECTE and DBE for small bowel Crohn's disease (CD).

METHODS

This retrospective study was conducted between 1 July 2016 and 1 November 2023 at the First Affiliated Hospital of Soochow University. The study included 72 CD patients who underwent both DECTE and DBE, with 4 patients repeating both procedures within 3 months.

RESULTS

The diagnostic rate of small bowel CD using DBE was 80.3%, which was higher than that using DECTE (65.8%, P = 0.044). The combined small bowel CD diagnostic rate was 89.5%, which was higher than that of DECTE alone (P < 0.001). The detection rate of stenosis using DBE was 46.1%, which was higher than that using DECTE (13.2%; P < 0.001). The combined detection rate of stenosis was 52.6%, which was higher than that of DECTE alone (P < 0.001). For ulcers, DBE had a higher detection rate (73.7%) than DECTE (7.9%; P < 0.001). The combined ulcer detection rate was 76.3%, which was higher than that of DECTE alone (P < 0.001). The detection rate of long ulcers (≥ 2 cm) and non-ileocecal ulcers by DBE were both 17.9%. For patients with abdominal pain, DBE had a diagnostic rate of 79.4%, higher than 63.5% of DECTE (χ2 = 3.889, P = 0.049). The combined diagnostic rate was 87.3%, which was higher than that of DECTE alone (χ2 = 9.626, P = 0.002). For patients with diarrhoea, the DBE's diagnostic rates were 86.8% and 68.4% for DECTE (P = 0.097). The combined diagnostic rate was 94.7%, higher than DECTE alone (χ2 = 7.092, P = 0.008). For patients with other symptoms, such as abdominal distension or vomiting, the DBE diagnostic rate was 79.4% compared with 61.8% for DECTE (P = 0.183). The combined diagnostic rate was higher than DECTE alone (χ2 = 6.620, P = 0.010). Furthermore, notable differences in C-reactive protein, erythrocyte sedimentation rate, faecal calprotectin, haemoglobin, platelet count, albumin, haematocrit, Crohn's Disease Activity Index scores, and Simple Endoscopic Score for Crohn's Disease scores were observed between ulcer-positive and ulcer-negative patients detected by DBE (P < 0.05), whereas DECTE did not show significant differences (P > 0.05).

CONCLUSIONS

DBE or the combined use of DECTE and DBE provides superior diagnostic performance for small bowel CD, particularly in detecting stenosis and ulcers, compared with DECTE alone. DBE can be used to identify long ulcers and non-ileocecal ulcers. Moreover, DBE helps diagnose small bowel CD across different clinical manifestations and assess disease activity in various inflammatory states.

Ultrasound of the bowel with a focus on IBD: the new best practice

Inflammatory Bowel Disease (IBD) is a lifelong chronic disease affecting any part of the gastrointestinal tract with a predilection for the terminal ileum. IBD patients require repeat imaging throughout the course of their disease, necessitating a safe, noninvasive, available, and repeatable method. Imaging is required at diagnosis, routine surveillance, and acute exacerbation of disease. Ultrasound imaging meets these demands with a high degree of accuracy and wide patient acceptance. Ultrasound provides high-resolution imaging and is excellent for detailed evaluation of the bowel wall and surrounding soft tissues. Regular greyscale bowel evaluation and color Doppler imaging now have accepted standards for evaluating disease activity based on wall thickness, perienteric inflammatory fat, and blood flow, which is invaluable in staging and grading disease. High-resolution dynamic real-time imaging on ultrasound has the ability to show functional as well as morphologic detail, including dysfunctional peristalsis associated with bowel stricture and incomplete mechanical bowel obstruction. Fibrostenotic and penetrating complications of IBD may be associated with an acute or chronic presentation that is easily assessed using ultrasound. Newer software technologies for ultrasound, including Contrast-Enhanced ultrasound and Shear wave elastography, have transformed ultrasound from a basic preliminary imaging technique into a highly sophisticated modality that is now competitive with CT and MR enterography for managing IBD patients. Our long experience with ultrasound of the bowel suggests that the new best practice would include ultrasound as the first test for evaluation of the bowel at any stage of the disease.

Bowel Ultrasound

Sonographic evaluation of the intestine is increasing in popularity due to its safety, noninvasive nature, accessibility, and high acceptability by patients. It is now recognized as one of the most valuable imaging modalities in the assessment of patients with inflammatory bowel disease. In addition, recent technical advances in ultrasound (US), especially contrast-enhanced US and shear wave elastography, have given US a competitive edge allowing for subjective and objective measurements of mural and mesenteric inflammation. The dynamic performance and high resolution of US allow for functional and morphologic assessment of the bowel, making it a desirable technique.

2024 Clinical Practice Guideline Update by the Infectious Diseases Society of America on Complicated Intra-abdominal Infections: Diagnostic Imaging of Suspected Acute Intra-abdominal Abscess in Adults, Children, and Pregnant People

This article is part of a clinical practice guideline update on the risk assessment, diagnostic imaging, and microbiological evaluation of complicated intra-abdominal infections in adults, children, and pregnant people, developed by the Infectious Diseases Society of America. In this article, the panel provides recommendations for diagnostic imaging of suspected acute intra-abdominal abscess. The panel's recommendations are based on evidence derived from systematic literature reviews and adhere to a standardized methodology for rating the certainty of evidence and strength of recommendation according to the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach.

Contrast-enhanced ultrasound fundamentals: the pharmacodynamics and pharmacokinetics of contrast. Basics of contrast-enhanced ultrasound imaging

Contrast-enhanced ultrasound (CEUS) is a medical imaging technique that offers multiple advantages over other modalities such as computed tomography (CT) and magnetic resonance imaging (MRI). These advantages include portability, no ionising radiation and no renal toxicity, with the great advantage of real-time imaging. CEUS has numerous established applications for the study of different pathologies, both intravenous and intracavitary administration. The contrast used is different in composition and function from CT or MRI contrast. It is a purely intravascular contrast and, therefore, the enhancement of the lesions may have some differences with respect to CT or MRI in the equilibrium phase. Ultrasound contrast has a very good safety profile, with infrequent, generally mild and immediate adverse reactions in intravascular use and no adverse reactions reported in intracavitary use. It is important to know the basics of contrast-enhanced ultrasound, the different ways to optimise the image and the different artefacts.

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.

Intestinal ultrasound for intestinal Behçet disease reflects endoscopic activity and histopathological findings

BACKGROUND/AIMS

Intestinal Behçet disease is typically associated with ileocecal punched-out ulcers and significant morbidity and mortality. Intestinal ultrasound is a noninvasive imaging technique for disease monitoring. However, no previous reports have compared intestinal ultrasound with endoscopic ulcer activity or histopathological findings for intestinal Behçet disease. We evaluated the usefulness of intestinal ultrasound for assessing the activity of ileocecal ulcers in intestinal Behçet disease.

METHODS

We retrospectively compared intestinal ultrasound findings with 73 corresponding endoscopic images and 6 resected specimens. The intestinal ultrasound findings were assessed for 7 parameters (bowel wall thickness, vascularity [evaluated using the modified Limberg score with color Doppler], bowel wall stratification, white-plaque sign [strong hyperechogenic lines or spots], mesenteric lymphadenopathy, extramural phlegmons, and fistulas), and endoscopic ulcer activity was classified into active, healing, and scar stages. Histopathological findings were evaluated by consensus among experienced pathologists.

RESULTS

Bowel wall thickness (P< 0.001), vascularity (P< 0.001), loss of bowel wall stratification (P= 0.015), and white-plague sign (P= 0.013) were significantly exacerbated in the endoscopic active ulcer stage. Receiver operating characteristic curve analysis revealed that a bowel wall thickness of > 5.5 mm (sensitivity 89.7%, specificity 85.3%) was potentially useful for detecting active lesions. When compared with histopathological findings, an increase in bowel wall thickness reflected the ulcer marginal ridge, and the white-plaque sign reflected the ulcer bottom.

CONCLUSIONS

Intestinal ultrasound is useful for monitoring intestinal ulcer activity in intestinal Behçet disease.

Diagnostic Accuracy of Intestinal Ultrasound in the Detection of Intra-Abdominal Complications in Crohn's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Crohn's disease [CD] is frequently associated with the development of strictures and penetrating complications. Intestinal ultrasound [IUS] is a non-invasive imaging modality ideal for point-of-care assessment. In this systematic review and meta-analysis we provide a current overview on the diagnostic accuracy of IUS and its advanced modalities in the detection of intra-abdominal complications in CD compared to endoscopy, cross-sectional imaging, surgery, and pathology.

METHOD

We conducted a literature search for studies describing the diagnostic accuracy of IUS in adult patients with CD-related intra-abdominal complications. Quality of the included studies was assessed with the QUADAS-2 tool. Meta-analysis was performed for both conventional IUS [B-mode] and oral contrast IUS [SICUS].

RESULTS

Of the 1498 studies we identified, 68 were included in this review and 23 studies [3863 patients] were used for the meta-analysis. Pooled sensitivities and specificities for strictures, inflammatory masses, and fistulas by B-mode IUS were 0.81 and 0.90, 0.87 [sensitivities] and 0.95, and 0.67 and 0.97 [specificities], respectively. Pooled overall log diagnostic odds ratios were 3.56, 3.97 and 3.84, respectively. Pooled sensitivity and specificity of SICUS were 0.94 and 0.95, 0.91 and 0.97 [sensitivities], and 0.90 and 0.94 [specificities], respectively. The pooled overall log diagnostic odds ratios of SICUS were 4.51, 5.46, and 4.80, respectively.

CONCLUSION

IUS is accurate for the diagnosis of intra-abdominal complications in CD. As a non-invasive, point-of-care modality, IUS is recommended as the first-line imaging tool if there is a suspicion of CD-related intra-abdominal complications.

Intestinal ultrasound in inflammatory bowel disease: New kid on the block

Intestinal ultrasound is an emerging technique for diagnosing and monitoring patients with inflammatory bowel disease (IBD). It is a simple, non-invasive, inexpensive, safe and reliable tool for monitoring patients with IBD. This technique has good diagnostic accuracy in the assessment of the extent and severity of IBD and its complications. The most commonly used parameters are bowel wall thickness, color Doppler flow, bowel wall stratification and peri-bowel inflammation. Various scoring systems have been developed utilizing the above parameters to monitor patients with IBD. It is a good tool to monitor response to therapy and follow-up for post-operative recurrence. Early response on intestinal ultrasound (IUS) predicts long-term clinical remission and mucosal healing in patients with Crohn's disease. In patients with ulcerative colitis (UC), the response to IUS can be assessed as early as two weeks. Recent data has emerged to predict the response to corticosteroids and colectomy in patients with acute severe UC. Point of care IUS in the outpatient clinic is an excellent tool to follow-up patients and guide clinical decision-making and has good acceptability among patients. It is an underutilized technique in spite of its appeal and the availability of evidence. Underutilization can be attributed to the lack of awareness, expertise and training centres. This review discusses the technical details and the evidence to support the use of IUS in IBD. We aim to increase awareness and use of intestinal ultrasound and build local expertise and data.

Intestinal MRI in Inflammatory Bowel Disease - Literature and Survey-Based Recommendations regarding Reporting by the German Radiological Society (DRG) and the German Competence Network for Inflammatory Bowel Diseases

BACKGROUND

MR-enterography/enteroclysis (MRE) is increasingly used for primary diagnosis, detection of complications, and monitoring of patients with inflammatory bowel disease (IBD). Standardization of reporting is relevant to ensure quality of the methodology and to improve communication between different faculties. The current manuscript describes the features that are required for optimized reporting of MRE in IBD.

METHODS

An expert consensus panel of radiologists and gastroenterologists conducted a systematic search of the literature. In a Delphi process, members of the German Radiological Society (DRG) and members of the Competence Network for Inflammatory Bowel Diseases voted on relevant criteria for the reporting of findings in MRE. Based on the voting results, statements were developed by the expert consensus panel.

RESULTS

Clinically relevant aspects of MRE findings have been defined to optimize reporting and to standardize terminology. Minimal requirements for standardized reporting are suggested. The statements focus on the description of disease activity as well as on complications of IBD. Attributes of intestinal inflammation are described and illustrated by exemplary images.

CONCLUSION

The current manuscript provides standardized parameters and gives practical recommendations on how to report and how to characterize MRE findings in patients with IBD.

KEY POINTS

· Systematic overview provides practice-oriented recommendations and names and evaluates the decisive criteria for reporting and interpretation of MRI in inflammatory bowel disease.. · Standardized terminology and reporting criteria for MRI in IBD improves interdisciplinary communication.. · Standardized collection and documentation of MRI findings in IBD helps to further establish the method and to improve care for IBD patients..

CITATION FORMAT

· Wessling J, Kucharzik T, Bettenworth D et al. Intestinal MRI in Inflammatory Bowel Disease - Literature and Survey-Based Recommendations regarding Reporting by the German Radiological Society (DRG) and the German Competence Network for Inflammatory Bowel Diseases. Fortschr Röntgenstr 2023; 195: 675 - 690.

Recent advances in the use of ultrasound in Crohn's disease

INTRODUCTION

A clear consensus exists on the role of IUS for the assessment and monitoring of Crohn's disease (CD) in the 'treat-to-target' strategy.

AREAS COVERED

IUS is an accurate tool for the management of CD. It is noninvasive and well tolerated. IUS has good-to-optimal inter-operator reliability either for assessing disease activity or for evaluating treatment response, especially combining Bowel Wall Thickness (BWT) and Color Doppler Signals (CDS). IUS is able to evaluate transmural remission (TR), the ultimate goal of the 'treat-to-target' strategy. Several studies confirmed its accuracy in the assessment of the post-operative recurrence (POR). Thanks to recent advances in trans-perineal ultrasound technique (TPUS), it allows to characterize peri-anal disease and its complications. Small intestine contrast ultrasound (SICUS) and contrast-enhancement ultrasound (CEUS) may improve IUS performance, particularly in stricturing or penetrating CD. Ultrasound elastography (USE) is raising interest for its accuracy in differentiating CD phenotypes (fibrotic versus inflamed).

EXPERT OPINION

IUS is a pivotal step in the management of CD, in early assessment as in therapeutic monitoring, with advantages of evaluating transmural response. Development and validation of novel ultrasound biomarkers of activity and fibrosis, especially those linked to advanced ultrasound techniques, are expected in the coming years.

Intestinal ultrasound as a non-invasive tool to monitor inflammatory bowel disease activity and guide clinical decision making

Intestinal ultrasound (IUS) is a non-invasive, real-time, cross-sectional imaging tool that can be used at the point-of-care to assess disease activity in patients with Crohn’s disease or ulcerative colitis. IUS promotes quick and impactful treatment decisions that can modify disease progression and enhance patient compliance. This review will summarize the technical aspects of IUS, the evidence to support the use of IUS in disease activity monitoring, the comparison of IUS to current standard of care monitoring modalities such as colonoscopy and calprotectin, and the optimal positioning of IUS in a tight-control monitoring strategy.

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.

Gastrointestinal Ultrasound in Emergency Setting

Acute bowel diseases are responsible for more than one third of subjects who were referred to the emergency department for acute abdominal pain and gastrointestinal evaluation. Gastrointestinal ultrasound (GIUS) is often employed as the first imaging method, with a good diagnostic accuracy in the setting of acute abdomen, and it can be an optimal diagnostic strategy in young females due to the radiation exposure related to X-ray and computed tomography methods. The physician can examine the gastrointestinal system in the area with the greatest tenderness by ultrasound, thus obtaining more information and data on the pathology than the standard physical examination. In this comprehensive review, we have reported the most relevant indications and advantages to using ultrasound in the investigation of abdominal acute pain.

Imaging Evaluation of Inflammatory Bowel Disease Complications

Inflammatory bowel disease (IBD) is a chronic inflammatory condition that can progress to fibrostenotic and penetrating complications. Cross-sectional imaging is often needed for accurate diagnosis of IBD complication and for planning the appropriate management strategy. Computed tomography enterography, magnetic resonance enterography, and IBD ultrasound have become key tools for clinicians and interventional endoscopists. This article highlights and discusses various radiologic imaging techniques and their application to the diagnosis and management of IBD complications.

Intestinal Ultrasound in the Assessment of Luminal Crohn’s Disease

Crohn’s disease is a chronic inflammatory disease affecting the gastrointestinal tract. Expert guidelines now recommend regular objective assessments as part of a treat-to-target approach. Intestinal ultrasound provides a noninvasive, patient-friendly modality for assessing Crohn’s disease without the risk of radiation exposure and does not require fasting or bowel preparation. Enhancement techniques, including oral and intravenous contrast, can improve disease-activity and complication detection. Due to its acceptability, intestinal ultrasound can be performed frequently, allowing for closer disease-activity monitoring and treatment adjustments. There have been significant advances in the utility of intestinal ultrasound; particularly for assessing disease activity during pregnancy and fibrosis detection utilising elastography. This review provides a comprehensive overview of performing intestinal ultrasound, the diagnostic accuracy, role in disease-activity monitoring, and recent advances in utilising ultrasound for the assessment of luminal Crohn’s disease.

Treat to transmural healing: how to incorporate intestinal ultrasound into the treatment of inflammatory bowel disease

Intestinal ultrasound (IUS) is emerging as a key tool to achieving the therapeutic target of transmural healing in inflammatory bowel disease (IBD). IUS is a non-invasive, radiation-free, imaging modality comparable to MRI, CT and ileocolonoscopy (IC). With the appropriate training and equipment, IUS can be an easily repeatable bedside test for IBD diagnosis and disease monitoring, including treatment response. Core to successful high quality IUS employment are appropriate training and expert techniques; however, the training pathway will not be explored in this review. Given the increasing shift towards objective assessment for tight disease control, gastroenterologist-led IUS should be incorporated into the armamentarium of imaging modalities alongside radiologists, to enhance our diagnostic and monitoring toolbox. This comprehensive review aims to outline the current literature around IUS and propose the placement of IUS in a treat-to-target algorithm in IBD. Ultimately, IUS facilitates timely management decisions to optimise patient care with potential to revolutionise patient outcomes, moving towards transmural healing as the holy grail of therapy in IBD.

[Position paper on reporting of intestinal ultrasound findings in patients with inflammatory bowel disease]

BACKGROUND

Intestinal ultrasound is increasingly used for primary diagnosis, detection of complications and monitoring of patients with Crohn's disease and ulcerative colitis. Standardization of reporting is relevant to ensure quality of the methodology and to improve communication between different specialties. The current manuscript describes the features required for optimized reporting of intestinal ultrasound findings in inflammatory bowel disease (IBD).

METHODS

An expert consensus panel of gastroenterologists, radiologists, pathologists, paediatric gastroenterologists and surgeons conducted a systematic literature search. In a Delphi- process members of the Kompetenznetz Darmerkrankungen in collaboration with members of the German Society for Radiology (DRG) voted on relevant criteria for reporting of findings in intestinal ultrasound. Based on the voting results statements were agreed by expert consensus.

RESULTS

Clinically relevant aspects of intestinal ultrasound (IUS) findings have been defined to optimize reporting and to standardize terminology. Minimal requirements for standardized reporting are suggested. The statements focus on description of disease activity as well as on complications of IBD. Attributes of intestinal inflammation are described and illustrated by exemplary images.

CONCLUSION

The current manuscript provides practical recommendations on how to standardize documentation and reporting from intestinal ultrasound findings in patients with IBD.

ECCO-ESGAR Topical Review on Optimizing Reporting for Cross-Sectional Imaging in Inflammatory Bowel Disease

BACKGROUND AND AIMS

The diagnosis and follow up of patients with inflammatory bowel disease [IBD] requires cross-sectional imaging modalities, such as intestinal ultrasound [IUS], magnetic resonance imaging [MRI] and computed tomography [CT]. The quality and homogeneity of medical reporting are crucial to ensure effective communication between specialists and to improve patient care. The current topical review addresses optimized reporting requirements for cross-sectional imaging in IBD.

METHODS

An expert consensus panel consisting of gastroenterologists, radiologists and surgeons convened by the ECCO in collaboration with ESGAR performed a systematic literature review covering the reporting aspects of MRI, CT, IUS, endoanal ultrasonography and transperineal ultrasonography in IBD. Practice position statements were developed utilizing a Delphi methodology incorporating two consecutive rounds. Current practice positions were set when ≥80% of the participants agreed on a recommendation.

RESULTS

Twenty-five practice positions were developed, establishing standard terminology for optimal reporting in cross-sectional imaging. Assessment of inflammation, complications and imaging of perianal CD are outlined. The minimum requirements of a standardized report, including a list of essential reporting items, have been defined.

CONCLUSIONS

This topical review offers practice recommendations to optimize and homogenize reporting in cross-sectional imaging in IBD.

Application of transabdominal ultrasound in Crohn's disease

Crohn's disease (CD), a chronic nonspecific intestinal inflammatory disorder of uncertain origin, is collectively referred to as inflammatory bowel disease with ulcerative colitis. In recent years, with the increasing incidence of CD, a greater demand has been put forward for disease diagnosis and inflammatory activity monitoring. With the development of ultrasound technology, transabdominal ultrasound has become more relevant for the diagnosis and follow-up of CD, providing an effective non-invasive examination tool for patients. This review summarizes several transabdominal ultrasound modalities and associated techniques that are presently being developed and utilized in clinical practice, describes the ultrasound manifestations of CD, and discusses the value and prospect of transabdominal ultrasonography in CD.

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.

Use of contrast-enhanced ultrasound in pediatrics

Although contrast-enhanced ultrasound has been shown to provide considerable benefits, particularly in pediatric patients, it is still used relatively rarely in Brazil. It has proven to be a safe technique, and adverse effects are rare. In this review, we address the technique and main applications of contrast-enhanced ultrasound in the pediatric population, including the evaluation of focal liver lesions, abdominal trauma, kidney grafts, liver grafts, bowel loops, and vesicoureteral reflux. It is important for pediatric radiologists to be acquainted with this promising tool, understanding its applications and limitations.

Bowel Ultrasound in Inflammatory Bowel Disease: How Far in the Grayscale?

Bowel ultrasound (BUS) is a non-invasive and accurate technique for assessing activity, extension of disease, and complications in inflammatory bowel diseases. The main advantages of BUS are its safety, reproducibility, and low costs. Ancillary technologies of BUS (i.e., color Doppler and wave elastography) could broaden the diagnostic power of BUS, allowing one to distinguish between inflammation and fibrosis. Considering the costs and invasiveness of colonoscopy and magnetic resonance, BUS appears as a fast, safe, and accurate technique. The objective measures of disease allow one to make clinical decisions, such as optimization, switch, or swap of therapy. Previous studies reported a sensitivity and a specificity of more than 90% compared to endoscopy and magnetic resonance. Lastly, transperineal ultrasound (TPUS) is a promising approach for the evaluation of perianal disease in Crohn’s disease (CD) and disease activity in patients with ulcerative proctitis or pouchitis. Bowel ultrasound is being incorporated in the algorithm of managing inflammatory bowel diseases. Transmural healing evaluated through ultrasonography is emerging as a complementary target for disease treatment. In this review, we aimed to summarize and discuss the current evidence on BUS in the management of inflammatory bowel diseases and to address the challenges of a full validation of this technique.

Sonographic Features of Abscess Maturation in a Porcine Model

Abscesses are walled-off collections of infected fluids that often develop as complications in the setting of surgery and trauma. Treatment is usually limited to percutaneous catheterization with a course of antibiotics. As an alternative to current treatment strategies, a histotripsy approach was developed and tested in a novel porcine animal model. The goal of this article is to use advanced ultrasound imaging modes to extract sonographic features associated with the progression of abscess development in a porcine model. Intramuscular or subcutaneous injections of a bi-microbial bacteria mixture plus dextran particles as an irritant led to identifiable abscesses over a 2 to 3 wk period. Selected abscesses were imaged at least weekly with B-mode, 3-D B-mode, shear-wave elastography and plane-wave Doppler imaging. Mature abscesses were characterized by a well-defined core of varying echogenicity surrounded by a hypoechoic capsule that was highly vascularized on Doppler imaging. 3-D imaging demonstrated the natural history of abscess morphology, with the abscess becoming less complex in shape and increasing in volume. Furthermore, shear-wave elastography demonstrated variations in stiffness as phlegmon becomes abscess and then liquefies, over time. These ultrasound features potentially provide biomarkers to aid in selection of treatment strategies for abscesses.

Point-of-Care Ultrasound Diagnosis of a Crohn's Disease-Related Intraabdominal Abscess in the Emergency Department

The emergency department (ED) diagnosis of Crohn’s disease (CD)-associated complications is typically established with abdominopelvic computed tomography imaging. Ultrasonography has been suggested as an effective alternative modality for diagnosing several CD complications, including intraabdominal abscesses. We report the identification of a CD-related intraabdominal abscess by emergency physician (EP)-performed point-of-care ultrasound (POCUS). This case highlights the feasibility of EPs integrating POCUS into the clinical decision-making for patients with inflammatory bowel disease in the ED.

Clinical characteristics, natural history, and outcomes of Crohn's-related intra-abdominal collections

BACKGROUND

Intra-abdominal collections in the form of abscesses or matted bowel loops, called phlegmons, might occur in patients with Crohn's disease (CD). The clinical characteristics and management of such conditions are not well described. We aim to characterize CD-related intra-abdominal collections clinically, and identify predictors of need for surgical interventions and the time to surgery.

METHODS

We utilized the Saudi Inflammatory Bowel Disease Information System (IBDIS) database to identify all patients treated for radiologically proven intra-abdominal abscesses or phlegmons since inception. Demographics, clinical data, clinical course, and treatment outcomes were recorded. Logistic regression analysis and survival analysis were used to identify predictors of surgical resection and differences in time to surgery between patient subgroups, respectively.

RESULTS

A total of 734 patients with a diagnosis of CD were screened and 75 patients were identified. The mean age was 25.6 ± 9.9 years and 51% were males. Nearly 60% of patients had abscesses larger than 3 cm while 13% had smaller abscesses and 36% had phlegmons. On presentation, the most commonly reported symptom was abdominal pain (99%) followed by weight loss (27%). About 89% of patients were treated with antibiotics during hospitalization for an average of 2.7 weeks. Steroids were prescribed for 52% of patients and tumor necrosis factor alpha (TNF-alpha) antagonists for 17%. Surgical resection was required for 33 patients (44% of the cohort) while 51% were managed with antibiotics and/or percutaneous drainage. The most common surgical intervention was ileocecal resection (45%). Although patients who underwent follow-up imaging were more likely to require early surgical intervention (P = 0.04), no statistically significant predictor of surgery could be identified from this cohort. Time to surgery varied numerically according to abscess size (HR = 1.18, 95% CI = 0.62-2.27, P = 0.61).

CONCLUSIONS

Although the majority of patients with CD-related intra-abdominal collections underwent surgical resection in this cohort, no obvious predictors of surgical intervention could be identified. The decision to perform early surgery appeared to be influenced by the findings observed on cross-sectional imaging during the follow-up of these collections.

Contrast-Enhanced Ultrasound (CEUS) in Non-Traumatic Abdominal Emergencies

Conventional ultrasound imaging (US) is the first-line investigation in acute non-traumatic abdominal emergencies, but sometimes it needs further examinations, such as computed tomography (CT), to reach a certain diagnosis. Contrast-enhanced ultrasound (CEUS), through injection of contrast medium, may provide the radiologist with additional information that could not be investigated with baseline US. It could help reach a diagnosis and rapidly determine the proper therapy in an emergency setting. The purpose of this review is to explain and illustrate the various possibilities and limitations of CEUS in acute non-traumatic abdominal diseases, in particular acute inflammation, parenchymal infarcts, and hemorrhages.

Bowel ultrasonography in acute abdomen: beyond acute appendicitis

Acute abdomen is a common reason for consultation in the emergency department. A broad spectrum of entities, including diverse diseases of the gastrointestinal tract, can cause acute abdomen. Although computed tomography is the technique most widely used to evaluate acute abdomen in the emergency department, abdominal ultrasound is often performed first and allows bowel disease to be suspected. This article describes the ultrasound features of diverse bowel diseases that can cause acute abdomen, such as acute diverticulitis, bowel obstruction, gastrointestinal perforation, bowel ischemia, intraabdominal fat necrosis, and miscellaneous processes such as endometriosis, foreign bodies, or vasculitis. Radiologists must be familiar with the different features of abnormal bowel that can be detected incidentally in patients without clinical suspicion of bowel disease. This article focuses on ultrasonographic signs of bowel disease; other articles in this series cover the ultrasonographic signs of acute appendicitis, inflammatory bowel disease, and infectious diseases.

Point-of-Care Ultrasound in Inflammatory Bowel Disease

Inflammatory bowel diseases [IBD], including Crohn's disease [CD] and ulcerative colitis [UC], are chronic, relapsing and destructive inflammatory disorders of the gastrointestinal tract which can lead to organ damage and impair quality of life. A 'treat-to-target' strategy based on activity and severity of disease and response to treatment with close monitoring of intestinal inflammation is recommended. Ileocolonoscopy [CS] is considered the first-line procedure for the assessment of IBD, and magnetic resonance enterography [MRE] is the current standard for assessing the small bowel and complications in CD, and has been proposed as an alternative procedure to CS in the evaluation of both ileo-colonic CD and UC. As that both CS and MRE are invasive and expensive procedures and unappealing to patients, they are unfeasible as frequent and repetitive tools for the monitoring of disease activity. Bowel ultrasound [US] represents a well-tolerated, non-invasive and cost-effective modality to manage IBD patients in clinical practice. Compared to CS and MRE, bowel US has been shown to have the same level of accuracy in assessing and monitoring disease activity and severity of both CD and UC. It can be performed at the point-of-care and therefore allow for real-time clinical decision-making. Point-of-care ultrasound [POCUS] is suggested as the stethoscope of the future and is gaining interest and diffusion in the medical field because it can be used for the bedside examination of patients. The aim of this review is to discuss point-of-care bowel ultrasound [POCBUS] in the management of patients with IBD.

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.

Ultrasound findings of Crohn's disease: correlation with MR enterography

Crohn's disease is a chronic inflammatory bowel disease characterized by periods of relative inactivity alternating with acute flare-ups. Imaging techniques play a fundamental role in the diagnosis and follow-up of Crohn's disease, providing information on the extent of disease, disease activity, and the presence of extramural complications. Because of the frequent re-evaluation required by the relapsing nature of Crohn's disease and the relative young age at which most patients are diagnosed, techniques that use ionizing radiation are best avoided in monitoring this population. Thus, magnetic resonance enterography (MRE) and ultrasonography (US) are the preferable techniques. Various studies have demonstrated that US is accurate in assessing the gut. Despite some clear advantages over MRE, US has long been underused in the evaluation of intestinal disease. This review presents an overview of the main imaging findings in Crohn's disease, correlating representative US images with MRE and surgical pathology specimens. We conclude that US reliably depicts both bowel-related and mesenteric features of Crohn's disease and US findings correlate strongly with MRE findings.

Recommendations of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU) on the use of abdominal ultrasound in inflammatory bowel disease

Ultrasound has an excellent diagnostic performance when Crohn's disease is suspected, when performing an activity assessment, or determining the extension and location of Crohn's disease, very similar to other examinations such as MRI or CT. It has a good correlation with endoscopic lesions and allows the detection of complications such as strictures, fistulas or abscesses. It complements colonoscopy in the diagnosis and, given its tolerance, cost and immediacy, it can be considered as a good tool for disease monitoring. In ulcerative colitis, its role is less relevant, being limited to assessing the extent and activity when it is not possible with other diagnostic techniques or if there are doubts with these. Despite its advantages, its use in inflammatory bowel disease (IBD) is not widespread in Spain. For this reason, this document reviews the advantages and disadvantages of the technique to promote knowledge about it and implementation of it in IBD Units.

The use of contrast-enhanced ultrasound for chronic inflammatory bowel disease

Intestinal ultrasound is a non-invasive, inexpensive, accessible imaging technique that is appropriate for the study of patients with inflammatory bowel disease (IBD). It provides an assessment of inflammatory activity and complications with a diagnostic accuracy similar to that of magnetic resonance imaging (MRI) and computed tomography (CT). Furthermore, it has proven to be of great value for the follow-up and monitoring of these patients. The addition of contrast enhancement has improved the diagnostic ability of intestinal ultrasound in the assessment of both inflammatory activity and complications. The development of dynamic studies able to quantify contrast arrival and determine a number of parameters in time-intensity curves (TICs) has increased the capability of intestinal ultrasound to identify inflammation and predict response to biologic therapy.

Crohn's disease at radiological imaging: focus on techniques and intestinal tract

Over recent years, inflammatory bowel diseases have become an issue of increased attention in daily clinical practice, due to both a rising incidence and improved imaging capability in detection. In particular, the diagnosis of Crohn's disease is based on clinical picture, laboratory tests and colonoscopy with biopsy. However, colonoscopic evaluation is limited to the mucosal layer. Thus, imaging modalities play a pivotal role in enriching the clinical picture, delivering information on intestinal and extraintestinal involvement. All the imaging modalities can be employed in evaluation of Crohn's disease patients, each of them with specific strengths as well as limitations. In this wide selection, the choice of a proper diagnostic framework can be challenging for the clinician. Therefore, the aim of this work is to offer an overview of the different imaging techniques, with brief technical details and diagnostic potential related to each intestinal tract.

Treatment of abdominal fistulas in Crohn's disease and monitoring with abdominal ultrasonography

OBJECTIVE

to assess the usefulness of medical treatment to achieve closure of internal fistulas detected on abdominal ultrasound in a series of patients with fistulizing Crohn's disease.

MATERIAL AND METHODS

a retrospective analysis was performed of the medical records of patients with Crohn's disease with a fistula detected on abdominal ultrasound from 2010 to 2018. The study included patients who received medical treatment after the diagnosis of this complication and underwent ultrasonographic monitoring of the therapeutic response. The factors associated with the response to medical treatment or the need for surgery were investigated.

RESULTS

forty-six patients were included in the study. Enteromesenteric (69.6 %) was the most common type of fistula and associated abscesses were found in 14 (30.4 %) patients. Fistulas were classified as complex in 20 patients. Treatment with immunosuppressants was started in 14 (30.4 %) cases and a biologic drug was added in 18 (39.1 %) patients. Complete closure of the abdominal fistula was observed with ultrasonography in 24 (52.2 %) of the 46 patients. The only factor related to fistula closure was the type of fistula and was more likely to occur in patients with an enteromesenteric fistula. Thirteen (28 %) of the 46 patients needed a surgical resection. The only factor with a significant correlation with a lower need for surgery was fistula closure after treatment (8.3 % vs 50 %, p = 0.002).

CONCLUSION

medical treatment achieves internal fistula closure in more than half of cases and almost a third require surgical treatment. Abdominal ultrasound can detect abdominal fistulas at an earlier stage and allow prompt treatment changes.

Usefulness of intestinal ultrasound in inflammatory bowel disease

Imaging techniques play a fundamental role in the initial diagnosis and follow-up of inflammatory bowel disease. Intestinal ultrasound has high sensitivity and specificity in patients with suspected Crohn's disease and in the detection of inflammatory activity. This technique enables the early diagnosis of intra-abdominal complications such as stenosis, fistulas, and abscesses. It has also proven useful in monitoring the response to treatment and in detecting postsurgical recurrence. Technical improvements in ultrasound scanners, technological advances such as ultrasound contrast agents and elastography, and above all increased experience have increased the role of ultrasound in the evaluation of the gastrointestinal tract. The features that make ultrasound especially attractive include its wide availability, its noninvasiveness and lack of ionizing radiation, its low cost, and its good reproducibility, which is important because it is easy to repeat the study and the study is well tolerated during follow-up. This review summarizes the role of intestinal ultrasound in the detection and follow-up of inflammatory bowel disease.

Bowel ultrasound: examination techniques and normal and pathologic patterns

Ultrasound is being increasingly used to study the digestive tract because it has certain advantages over other techniques such as endoscopy, CT enterography, and MR enterography. Ultrasound can be used to evaluate the bowel wall and the elements that surround it without the need for contrast agents; its ability to evaluate the elasticity and peristalsis of these structures is increasing interest in its use. This article describes the techniques and modalities of bowel ultrasound, as well as the normal features of the bowel wall and contiguous structures. It uses a practical approach to review the main pathological findings and their interpretation, and the different patterns of presentation, which will help orient the diagnosis.

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.