US evaluation of patients affected by IBD: How to do it, methods and findings

Prognostic role of intestinal ultrasound in Crohn’s disease

The majority of patients affected by Crohn’s disease (CD) develop a chronic condition with persistent inflammation and relapses that may cause progressive and irreversible damage to the bowel, resulting in stricturing or penetrating complications in around 50% of patients during the natural history of the disease. Surgery is frequently needed to treat complicated disease when pharmacological therapy failes, with a high risk of repeated operations in time. Intestinal ultrasound (IUS), a non-invasive, cost-effective, radiation free and reproducible method for the diagnosis and follow-up of CD, in expert hands, allow a precise assessment of all the disease manifestations: Bowel characteristics, retrodilation, wrapping fat, fistulas and abscesses. Moreover, IUS is able to assess bowel wall thickness, bowel wall stratification (echo-pattern), vascularization and elasticity, as well as mesenteric hypertrophy, lymph-nodes and mesenteric blood flow. Its role in the disease evaluation and behaviour description is well assessed in literature, but less is known about the potential space of IUS as predictor of prognostic factors suggesting response to a medical treatment or postoperative recurrence. The availability of a low cost exam as IUS, able to recognize which patients are more likely to respond to a specific therapy and which patients are at high risk of surgery or complications, could be a very useful instrument in the hands of IBD physician. The aim of this review is to present current evidence about the prognostic role that IUS can show in predicting response to treatment, disease progression, risk of surgery and risk of post-surgical recurrence in CD.

Comparison of Diagnostic Performance of Ultrasonography and Magnetic Resonance Enterography in the Assessment of Active Bowel Lesions in Patients with Crohn’s Disease: A Systematic Review and Meta-Analysis

We aimed to evaluate and compare the diagnostic performances of ultrasonography (US) and magnetic resonance enterography (MRE) in assessing active bowel lesions in patients with Crohn’s disease (CD). Materials and Methods: We searched PubMed and EMBASE for studies in which US and MRE were used to assess active bowel lesions in CD patients. Bivariate random effect meta-analytic methods were used to estimate pooled sensitivity, specificity, and hierarchical summary receiver operating characteristic (HSROC) curves. We performed a meta-regression analysis to explore the source of study heterogeneity. Results: Eleven studies involving 752 patients were included. US exhibited a pooled sensitivity of 86% (95% confidence interval (CI) 72–94), pooled specificity of 88% (95% CI 78–94), and HSROC of 0.93 in 10 studies. MRE exhibited a pooled sensitivity of 88% (95% CI 76–95), pooled specificity of 87% (95% CI 73–95), and an HSROC of 0.94 in eight studies. In seven studies comparing the diagnostic performances of US and MRE, the summary sensitivity of US and MRE were 86% (95% CI 65–96, I² = 92.1) and 86% (95% CI 72–93, I² = 88.1) (p = 0.841), respectively. The summary specificity of US and MRE were 87% (95% CI 78–93, I² = 79.8%) and 84% (72–90, I² = 72.5%) (p = 0.431), respectively, which showed no statistical differences. On meta-regression analysis, studies from Europe (p = 0.002), those that used linear US probes (p = 0.012), those on small bowel lesions (p = 0.01), and those with outcomes as combined features (active inflammation) reported higher US sensitivity than those from other regions, those that used both linear and convex US probes, those on small and large bowels, and those with outcome as one feature (bowel wall thickening or ulcer). Studies with pediatric patients (p = 0.001), those with reference standards including US (p = 0.001), and outcomes as combined features (p = 0.01) reported higher MRE specificity than those with adult populations, reference standards other than the US, and outcomes as one feature. Conclusions: In spite of considerable heterogeneity in the included studies, both US and MRE can diagnose active bowel lesions with comparable diagnostic accuracy in patients with CD. The study region, type of US probe, lesion location, investigated outcome for US sensitivity and study population, reference standards, and investigated outcomes for MRE specificity were potential sources of heterogeneity.

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.

Observer agreement for small bowel ultrasound in Crohn's disease: results from the METRIC trial

Purpose

To prospectively evaluate interobserver agreement for small bowel ultrasound (SBUS) in newly diagnosed and relapsing Crohn’s disease.

Methods

A subset of patients recruited to a prospective trial comparing the diagnostic accuracy of MR enterography and SBUS underwent a second SBUS performed by one of a pool of six practitioners, who recorded the presence, activity and location of small bowel and colonic disease. Detailed segmental mural and extra-mural observations were also scored. Interobserver variability was expressed as percentage agreement with a construct reference standard, split by patient cohort, grouping disease as present or absent. Prevalence adjusted bias adjusted kappa (PABAK), and simple percentage agreement between practitioners, irrespective of the reference standard, were calculated.

Results

Thirty-eight patients (11 new diagnosis, 27 relapse) were recruited from two sites. Overall percentage agreement for small bowel disease presence against the consensus reference was 82% (52–95% (95%CI)), kappa coefficient (κ) 0.64, (substantial agreement) for new diagnosis and 81%, κ 0.63 (substantial agreement) for the relapsing cohort. Agreement for colonic disease presence was 64%, κ 0.27 (fair agreement) in new diagnosis and 78%,κ 0.56 (moderate agreement) in the relapsing cohort. Simple agreement between practitioners was 84% and 87% for small bowel and colonic disease presence respectively. Practitioners agreed on small bowel disease activity in 24/27 (89%) where both identified disease. Kappa agreement for detailed mural observations ranged from κ 0.00 to 1.00.

Conclusion

There is substantial practitioner agreement for small bowel disease presence in newly diagnosed and relapsing CD patients, supporting wider dissemination of enteric US.

Electronic supplementary material

The online version of this article (10.1007/s00261-020-02405-w) contains supplementary material, which is available to authorized users.

Intestinal ultrasonography in adults with Crohn's disease: a 2020 update

In the last years intestinal ultrasonography (IUS) has increased its role in the management of inflammatory bowel diseases (IBD), that include Crohn's disease (CD) and ulcerative colitis. This is due to the fact that IUS is a non-invasive, inexpensive, and well-tolerated examination technique. Furthermore, it allows a real-time diagnosis with no radiation exposure. Usually, convex and linear probes with frequency between 3.5 and 12 MHz are used, also with the Color- Power Doppler. Focusing on CD, the IUS images of clinical interest are: bowel wall thickening (greater than 3 mm), pseudostratification and the wall vascularization. Moreover, IUS demonstrates inflammatory mass, loss of colonic haustration and the complications of the disease, such as stenosis, abscesses, and fistulas as well as other extraintestinal manifestations, such as lymph node enlargement and changes in the appearance of the mesenteric adipose tissue (creeping fat). Oral and intravenous contrast are used to obtain a better visualization of the bowel wall and to increase the diagnostic accuracy of IUS. In particular, intravenous contrast, administered during the procedure, allows to differentiate between active disease (bowel wall enhancement) and the fibrostenotic complications. Contrast-enhanced ultrasonography (CEUS) was proven to be useful in the follow-up and the disease recurrence detection. Beyond the support in the initial diagnosis, IUS has an important role in the follow-up of patients with CD, to monitor the response to the medical therapy and to detect possible complications. Furthermore, it can predict the recurrences after surgery, with more accuracy if Color-Doppler is used.

Utility of MR enterography and ultrasound for the investigation of small bowel Crohn's disease

Cross sectional Imaging plays an increasingly important role the diagnosis and management of Crohn's disease. Particular emphasis is placed on MRI and Ultrasound as they do not impart ionising radiation. Both modalities have reported high sensitivity for disease detection, activity assessment and evaluation of extra-luminal complications, and have positive effects on clinical decision making. International Guidelines now recommend MRI and Ultrasound in the routine management of Crohn's disease patients. This article reviews the current evidence base supporting both modalities with an emphasis on the key clinical questions. We describe current protocols, basic imaging findings and highlight areas in need of further research.

LEVEL OF EVIDENCE

5 Technical Efficacy: Stage 4 J. MAGN. RESON. IMAGING 2017;45:1573-1588.

Role of ultrasound in colorectal diseases

Ultrasound is an undervalued non-invasive examination in the diagnosis of colonic diseases. It has been replaced by the considerably more expensive magnetic resonance imaging and computed tomography, despite the fact that, as first examination, it can usefully supplement the diagnostic process. Transabdominal ultrasound can provide quick information about bowel status and help in the choice of adequate further examinations and treatment. Ultrasonography, as a screening imaging modality in asymptomatic patients can identify several colonic diseases such as diverticulosis, inflammatory bowel disease or cancer. In addition, it is widely available, cheap, non-invasive technique without the use of ionizing radiation, therefore it is safe to use in childhood or during pregnancy, and can be repeated at any time. New ultrasound techniques such as elastography, contrast enhanced and Doppler ultrasound, mini-probes rectal and transperineal ultrasonography have broadened the indication. It gives an overview of the methodology of various ultrasound examinations, presents the morphology of normal bowel wall and the typical changes in different colonic diseases. We will pay particular attention to rectal and transperineal ultrasound because of their outstanding significance in the diagnosis of rectal and perineal disorders. This article seeks to overview the diagnostic impact and correct indications of bowel ultrasound.

Ultrasound features of pediatric Crohn disease: a guide for case interpretation

With the emerging use of ultrasound in the evaluation of children with Crohn disease presenting with acute abdominal symptoms, there is a need to become familiar with the sonographic features of this disease. Our aim is to provide a primer of the characteristic intramural and extramural US findings in children with Crohn disease to serve as a practical and systematic guide to interpretation.

Prospective qualitative and quantitative non-invasive evaluation of intestinal acute GVHD by contrast-enhanced ultrasound sonography

Intestinal acute GVHD (I-aGVHD) is a life-threatening complication after allografting. Non-invasive bed-side procedures to evaluate extension and treatment response are still lacking. We hypothesized that, during I-aGVHD, contrast-enhanced ultrasound sonography (CEUS) could detect microcirculation changes (MVC) of the bowel wall (BW) and help to monitor treatment response. We prospectively employed CEUS in 83 consecutive patients. Of these, 14 patients with biopsy-proven intestinal GVHD (I-GVHD) were defined as the study group, whereas 16 patients with biopsy-proven stomach GVHD (U-GVHD) without intestinal symptoms, 6 normal volunteers and 4 patients with neutropenic enterocolitis were defined as the control group. All patients were evaluated with both standard ultrasonography (US) and CEUS at the onset of intestinal symptoms, during clinical follow-up and at flare of symptoms. Standard US revealed BW thickening of multiple intestinal segments, useful to determine the extension of GVHD. CEUS showed MVC, which correlated with GVHD activity, treatment response, and predicted flare of intestinal symptoms. US and CEUS findings were superimposable at diagnosis and in remission. CEUS was, however, more sensitive and specific to identify subclinical activity in patients with clinical relevant improvement. These findings were not observed in the control groups. CEUS is a non-invasive, easily reproducible bed-side tool useful to monitor I-aGVHD.

Usefulness of abdominal ultrasonography with studies of the intestinal loops in Turner syndrome patients

Turner syndrome, a chromosomal disorder caused by partial or complete absence of one of the two X chromosomes, is characterized by an increased incidence (compared with that in the normal population) of either autoimmune disorders, including chronic inflammatory bowel diseases, or angiodysplasia of the small intestine. Because ultrasonography and color Doppler ultrasound are widely used to investigate gastrointestinal disorders, we decided to carry out an ultrasound-based screening study in patients with Turner syndrome to determine whether this method might be useful in the follow-up of this population.

Radiation exposure in patients with inflammatory bowel disease--primum non nocere?

BACKGROUND

Patients with Inflammatory Bowel disease (IBD) are frequently exposed to diagnostic medical radiation for the diagnosis and evaluation of their disease. Despite increasing awareness of the potentially serious downstream effects, few studies have quantified radiation exposure in IBD patients.

METHODS

We conducted a retrospective review of 280 consecutive patients attending IBD clinics at our hospital. All incidences of diagnostic medical radiation from initial diagnosis until 30 June 2010 inclusive were recorded. The radiation dose for each procedure was obtained from standardized tables and the effective dose for each procedure calculated by multiplying this value by the number of procedures during the study period. The sum of doses received was the cumulative effective dose.

RESULTS

The mean and median cumulative effective radiation doses were 10.17 mSv and 4.12 mSv respectively. Crohn's disease patients had significantly higher cumulative effective radiation exposure than UC patients (p < 0.001) with exposure exceeding 10 mSv in 58.3%, 25 mSv in 18.1% and 50 mSv in 6.3%, respectively. Smoking status, disease duration, and previous surgery were significant predictors for increased radiation exposure even after adjusting for other predictors. 47 small bowel magnetic resonance (MR) studies were undertaken as an alternative to ionising radiation in the last 3 years.

CONCLUSIONS

Patients with IBD, particularly those with Crohn's disease, are exposed to significant amounts of diagnostic medical radiation in their lifetime. Clinicians must remain vigilant to the risk of cumulative radiation when evaluating these patients and consider non-ionizing alternatives such as intestinal ultrasound and MR imaging where clinically appropriate.

Color-coded duplex sonography compared to multidetector computed tomography for the diagnosis of crohn disease relapse and complications

OBJECTIVES

The purpose of this study was to evaluate the accuracy of color-coded duplex sonography for the diagnosis of Crohn disease relapse and complications compared to multidetector computed tomography (CT).

METHODS

The Institutional Ethics Committee approved the protocol research, and written consent forms were obtained. Patients with a diagnosis of Crohn disease presenting with symptoms of relapse or complications (54 patients; 27 female; ages 9-80 years; mean, 34.6 years) were enrolled. Patients underwent color-coded duplex sonography and multidetector CT examinations within 2 weeks of each other. Multidetector CT was the reference standard. The location and extent of diseased bowel, wall thickness, stenosis, hyperemia, mesenteric fat thickening, lymphadenopathy, abscesses, fistulas, peritoneal fluid, and signs of hepatobiliary disease were searched for.

RESULTS

About of 80% of the patients had terminal ileal involvement, and 55% had disease confined to the ileum. A significant correlation between the two modalities was found regarding wall thickness, abscesses, and fistulas (P < .05). Color-coded duplex sonography had sensitivity and specificity of 88% and 53%, respectively, for diagnosis of luminal stenosis. Hyperemia was more commonly diagnosed on color-coded duplex sonography. Color-coded duplex sonography had sensitivity and specificity of 84% and 83% for diagnosis of mesenteric fat thickening and lymphadenopathy and 66% and 86% for peritoneal fluid. Fatty liver was found in 18% and gallstone disease in 6%.

CONCLUSIONS

Color-coded duplex sonography was accurate in diagnosing the disease location, wall thickness, and extraintestinal inflammatory findings associated with Crohn disease, potentially placing it as the first-line imaging modality for the diagnosis of Crohn disease relapse and complications.

Noninvasive imaging of the small bowel in Crohn's disease: the final frontier

The substantial morbidity and mortality associated with Crohn's disease underlines the importance of accurate assessment at presentation, during follow-up, when investigating complications, and when evaluating the response to therapeutic interventions. Accurate methods are required to quantify the severity and extent of disease.

Ultrasonographic assessment of colonic wall in moderate-severe ulcerative colitis: comparison with endoscopic findings

BACKGROUND

Bowel ultrasound has been shown to be a useful tool to evaluate patients with inflammatory bowel disease, especially Crohn's disease. However, such data are still scarce in ulcerative colitis patients.

AIMS

To establish the value of bowel ultrasound in moderate to severe ulcerative colitis patients, and compare these data with endoscopic findings.

PATIENTS AND METHODS

Endoscopic, ultrasound and C-reactive protein data from 51 patients with moderate to severe ulcerative colitis observed during a 3-year period were retrospectively obtained and analysed.

RESULTS

All patients displayed pathological thickness (>4 mm) of the colon wall. This value strongly correlated with C-reactive protein values (p=0.0001) and the endoscopic score (p<0.0001). Also, a strong correlation (p<0.0001) was found between CRP values and endoscopic score.

CONCLUSIONS

Bowel ultrasound, in expert hands, may represent a useful adjunctive (or first line) tool for the evaluation of patients with moderate to severe ulcerative colitis.

Ultrasound of the bowel in children: how we do it

Advances in US like high-resolution transducers, harmonic imaging and panoramic modality have overcome some of the obstacles for sonography of the small and large bowel that existed in the past. In a number of centers, bowel US is an established routine method both in adults in children. Bowel US has the distinct advantages of being widely available, relatively cheap, free of radiation and easy to perform. In addition, US of the bowel demonstrates both mural and extramural pathological changes. Patients with inflammatory bowel disease have frequent imaging studies due to disease recurrences and need of follow-up after treatment. Thus this group of pediatric patients benefits most from an optimized and standardized bowel US. This review provides a comprehensive step-by-step approach how to perform US of the bowel in children with emphasis on imaging inflammatory bowel changes. It is meant to serve like a recipe and facilitate the routine performance of US of the bowel in children.

Application of transabdominal ultrasound in the detection of inflammatory bowel disease

As the incidence of inflammatory bowel disease (IBD) increases in recent years, accurate diagnosis of the disease becomes much more important. Moreover, the wide use of new targeted drugs requires precise evaluation of their therapeutic effects. Transabdominal ultrasound, as a newly emerging noninvasive method, plays an important role in diagnosing IBD, evaluating disease activity, and observing therapeutic effects. In this article, we will review the application of transabdominal ultrasound in the detection of IBD.