Failure of gastroenterologists to apply intestinal ultrasound in inflammatory bowel disease in the Asia-Pacific: a need for action

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.

Assessing vitamin D as a biomarker in inflammatory bowel disease

Background and Aim

A reliable serum biomarker for inflammatory bowel disease (IBD) activity is needed. Vitamin D is involved in inflammation and has been demonstrated to be low in IBD patients with active disease. It is routinely measured in IBD patients. Therefore, vitamin D may have a role as a serum biomarker in IBD. This study aims to investigate whether serum vitamin D may be useful as a biomarker in IBD in a real-world IBD population.

Methods

Patients were identified by review of fecal calprotectin (FCP) results, and those who had a clinical review, vitamin D test, and FCP performed within 3 months were included. Clinical scores were calculated from chart review. Nonparametric tests were used to investigate vitamin D and FCP levels, serum biomarkers, and clinical scores.

Results

Of 616 patients identified, 325 episodes of matched vitamin D level and biomarker data were obtained. A statistically significant correlation was found between vitamin D levels and FCP levels for all patients (r = -0.19 [s -0.29 to -0.080], P < 0.001]. This remained true when patients were divided into IBD subsets. Low vitamin D was associated with partial Mayo scores and C-reactive protein (CRP) to albumin ratio in ulcerative colitis, and CRP and CRP/albumin ratio in Crohn's disease.

Conclusion

Vitamin D level is negatively correlated with FCP and it may be considered as an adjunct biomarker at this stage. A prospective study would be beneficial to investigate further correlations between vitamin D and existing biomarkers of inflammation in IBD.

IBD barriers across the continents - East Asia

Inflammatory bowel diseases (IBDs) are chronic illnesses with significant morbidities and impact on patients' quality of life. There has been a rapid increase in the incidence of IBD in East Asia in recent decades. However, there is a huge unmet need in the diagnosis and management of IBD in this region. With the increasing awareness of IBD in East Asia and a persistently high rate of tuberculosis in this region, this poses a significant challenge in the diagnosis and management of IBD. In this review, we will explore the barriers to the diagnosis and management of IBD in the East Asia, hoping to provide an insight on how to improve the healthcare system in the management of this complex disease.

Evaluation of intestinal ultrasound for disease activity assessment in patients with inflammatory bowel disease: A cross-sectional study at a tertiary centre in Malaysia

Background

The use of intestinal ultrasound (IUS) in the management of inflammatory bowel disease (IBD) is emerging. We aim to determine the performance of IUS in the assessment of disease activity in IBD.

Methods

This is a prospective cross-sectional study of IUS performed on IBD patients in a tertiary centre. IUS parameters including intestinal wall thickness, loss of wall stratification, mesenteric fibrofatty proliferation, and increased vascularity were compared with endoscopic and clinical activity indices.

Results

Among the 51 patients, 58.8% were male, with a mean age of 41 years. Fifty-seven percent had underlying ulcerative colitis with mean disease duration of 8.4 years. Against ileocolonoscopy, IUS had a sensitivity of 67% (95% confidence interval (CI): 41-86) for detecting endoscopically active disease. It had high specificity of 97% (95% CI: 82-99) with positive and negative predictive values of 92% and 84%, respectively. Against clinical activity index, IUS had a sensitivity of 70% (95% CI: 35-92) and specificity of 85% (95% CI: 70-94) for detecting moderate to severe disease. Among individual IUS parameters, presence of bowel wall thickening (>3 mm) had the highest sensitivity (72%) for detecting endoscopically active disease. For per-bowel segment analysis, IUS (bowel wall thickening) was able to achieve 100% sensitivity and 95% specificity when examining the transverse colon.

Conclusions

IUS has moderate sensitivity with excellent specificity in detecting active disease in IBD. IUS is most sensitive in detecting a disease at transverse colon. IUS can be employed as an adjunct in the assessment of IBD.

Point-of-Care Ultrasound Educational Development in Australasia: A Scoping Review

Point-of-care ultrasound (PoCUS) technology is evolving rapidly and is being adopted by many health professionals in their clinical practice. Ultrasound is a complex skill requiring dedicated training. Appropriate integration of ultrasound education into medical, surgical, nursing and allied health professions is a current challenge worldwide. There are patient safety implications for use of ultrasound without adequate training and frameworks. The purpose of the review was to overview the status of PoCUS education in Australasia; investigate what is being taught and learned about ultrasound across the health professions; and identify potential gaps. The review was limited to postgraduate and qualified health professionals with established or emerging clinical use for PoCUS. A scoping review methodology was used to include literature in peer-reviewed articles, policies, guidelines, position statements, curricula and online material relating to ultrasound education. One hundred thirty-six documents were included. The literature revealed heterogeneity in ultrasound teaching and learning across the health professions. Several health professions lacked any defined scopes of practice, policies or curricula. Significant investment in resourcing ultrasound education is required to address the current needs in Australia and New Zealand.

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.

Positioning intestinal ultrasound in a UK tertiary centre: significant estimated clinical role and cost savings

OBJECTIVE

Intestinal ultrasound (IUS) is an inexpensive, non-invasive method of diagnosing and monitoring inflammatory bowel disease (IBD). We aimed to establish the proportion of lower gastrointestinal endoscopies (LGIEs) and magnetic resonance enterographies (MREs) that could have been performed as IUS, the potential pathology miss-rates if IUS was used and the associated cost savings.

METHODS

All MREs and LGIEs performed for either assessment of IBD activity or investigation of possible IBD, performed at a single UK tertiary centre in January 2018, were retrospectively reviewed against predetermined criteria for IUS suitability. Case outcomes were recorded and cost of investigation if IUS was performed instead was calculated.

RESULTS

73 of 260 LGIEs (28.1%) and 58 of 105 MREs (55.2%) met the criteria for IUS suitability. Among potential IUS-suitable endoscopy patients, one case each of a <5 mm adenoma and sessile serrated lesion were found; no other significant pathology that would be expected to be missed with IUS was encountered. Among IUS-suitable MRE patients, no cases of isolated upper gastrointestinal inflammation likely to be missed by IUS were found, and extraintestinal findings not expected to be seen on IUS were of limited clinical significance. The predicted cost saving over 1 month if IUS was used instead was £8642, £25 866 and £5437 for MRE, colonoscopy and flexible sigmoidoscopy patients, respectively.

CONCLUSION

There is a significant role for IUS, with annual projected cost savings of up to almost £500 000 at our centre. Non-inflammatory or non-gastrointestinal pathology predicted to be missed in this cohort was of limited clinical significance.

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

BACKGROUND

Intestinal ultrasound (IUS) is a non-invasive modality for monitoring disease activity in inflammatory bowel diseases (IBD). IUS training currently lacks well-defined standards and international consensus on competency criteria.

AIM

To achieve international consensus on what competencies should be expected from a newly certified IUS practitioner.

METHODS

A three-round, iterative Delphi process was conducted among 54 IUS experts from 17 countries. Round 1 was a brainstorming phase with an open-ended question to identify the knowledge and skills that experts believe a newly certified IUS practitioner should possess. The experts' suggestions were then organised into statements by a Steering Committee. In round 2, the experts commented upon and rated the statements, which were revised accordingly. In round 3, the experts rated the revised statements. Statements meeting the pre-defined consensus criterion of at least 70% agreement were included in the final list of statements.

RESULTS

In total, 858 items were suggested by the experts in the first round. Based on these suggestions, 55 statements were organised into three categories: knowledge, technical skills and interpretation skills. After the second round, 53 revised statements remained. After the final round, a total of 41 statements had achieved consensus.

CONCLUSIONS

We established international, expert consensus on the knowledge and skills that should be expected from newly certified IUS practitioners. These consensus statements are the first step towards mastery learning for IUS training. Educators can utilise these statements to design training programmes and evaluate the competencies of trainees before they engage in independent practice.

Surgical Management of Small Bowel Crohn's Disease

Crohn's disease in the small bowel could present itself as an inflammatory stricture, a fibrotic stricture as penetrating disease or a combination of both. It is pertinent to differentiate the disease process as well as its extent to effectively manage the disease. Currently, a combination of medical and surgical therapies forms part of the treatment plan while the debate of which therapy is better continues. In managing the strictures, identification of the disease process through imaging plays a pivotal role as inflammatory strictures respond to anti-tumor necrosis factor (TNF) and biological agents, while fibrotic strictures require endoscopic or surgical intervention. Recent evidence suggests a larger role for surgical excision, particularly in ileocolic disease, while achieving a balance between disease clearance and bowel preservation. Several adaptations to the surgical technique, such as wide mesenteric excision, side to side or Kono-S anastomosis, and long-term metronidazole therapy, are being undertaken even though their absolute benefit is yet to be determined. Penetrating disease requires a broader multidisciplinary approach with a particular focus on nutrition, skincare, and intestinal failure management. The current guidance directs toward early surgical intervention for penetrating disease when feasible. Accurate preoperative imaging, medical management of active diseases, and surgical decision-making based on experience and evidence play a key role in success.

Point-of-Care Testing and Home Testing: Pragmatic Considerations for Widespread Incorporation of Stool Tests, Serum Tests, and Intestinal Ultrasound

Breaking through the biologic therapy efficacy plateau for inflammatory bowel disease requires the strategic development of personalized biomarkers in the tight control model. After risk stratification early in the disease course, targeted serial monitoring consistently to assess clinical outcomes in response to therapy allows for quick therapeutic adjustments before bowel damage can occur. Point-of-care intestinal ultrasound performed by the treating gastroenterologist is an accurate cross- sectional biomarker that monitors intestinal inflammation in real-time, enhances patient care, and increases shared understanding to help achieve common treatment goals. Combining intestinal ultrasound during a clinic visit with existing serum and stool biomarkers in a home testing setup with electronic health monitoring allows for an optimized, patient-centered personalized treatment algorithm that may improve treatment outcomes. Here, we review the current state, pragmatic considerations, and future implications of point-of-care testing and home testing for noninvasive inflammatory bowel disease monitoring in the tight control model.

A Novel Noninvasive Method for Quantitative Detection of Colonic Dysmotility Using Real-Time Ultrasonography

INTRODUCTION

Colonic motility disorders are a frequent clinical problem caused by various drugs and diseases. However, the etiology of colonic dysmotility is often unclear due to the lack of in vivo methods, including rapid dynamic assessment.

OBJECTIVES

The aim of this study was to establish a novel quantitative method to objectively assess colonic motility using ultrasonography.

METHODS

We applied echocardiographic speckle tracking-based strain imaging to analyze murine colonic motility. A trace line was placed on the boundary between the proximal wall of the colon and the inner cavity to analyze colonic wall displacement and strain rate. Locomotion activities of the colonic wall were used to quantify colonic motility via ultrasonography.

RESULTS

We found that ultrasonography can quantitatively detect a decrease in colonic motility induced by loperamide, an antidiarrheal drug. These quantitative data were consistent with the imaging findings of colonic peristalsis and colon transit time. Additionally, ultrasonography also revealed changes in colonic motility over short intervals. Furthermore, we have shown that ultrasonography can quantitatively and noninvasively detect colonic dysmotility and hypervascularity of the colonic wall in colitis mice.

CONCLUSIONS

These findings suggest that ultrasonography is a useful in vivo method for objectively monitoring changes in colonic motility caused by drugs and diseases.

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 assessment of inflammatory bowel disease in the emergency department: A case series and review of the literature

The use of sonography for diagnosing inflammatory bowel disease (IBD) has been reported in the radiology literature but is not common practice in the hands of emergency physicians (EPs). We present a series of three cases where IBD was managed by an EP using point-of-care ultrasonography (POCUS), and discuss the sonographic features of IBD including bowel wall thickening, increased blood flow on color Doppler, infiltration of surrounding fatty tissue, and presence of intraperitoneal fluid. Complications such as bowel strictures and peri-colic abscess are also described. We suggest that the use of POCUS for the assessment of IBD patients in the ED may expedite both diagnosis and treatment, as well as minimize the use of additional imaging.

Systematic Review: Gastrointestinal Ultrasound Scoring Indices for Inflammatory Bowel Disease

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Utility of bowel ultrasound in assessing disease activity in Crohn's disease

BACKGROUND

Gastrointestinal ultrasound (GIUS) has been used increasingly for monitoring inflammatory bowel disease (IBD) patients. The aim of this study was to assess the utility of GIUS in assessing disease activity in Crohn's disease (CD).

METHODS

Consecutive patients with CD (diagnosis established for at least 6 months) between July 2017 and July 2018 requiring assessment of disease activity were prospectively assessed by magnetic resonance enterography, colonoscopy (CS), and GIUS within a 2-week period and without any change in ongoing treatment. Features on GIUS which correlated with disease activity were assessed. Sensitivity and specificity of the GIUS in assessing disease activity and localization were calculated.

RESULTS

Thirty-five patients were enrolled in the study. Bowel wall thickness (BWT) ≥ 3 mm and Doppler activity ≥ 2 had the highest sensitivity (100% and 95.6%, respectively) for detecting active disease on CS. BWT ≥ 3 mm had sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 83.3%, 92%, and 100%, respectively for assessing active disease. Combination of median BWT, Doppler activity, and loss of bowel wall stratification correlated with simplified endoscopic score (SES) for CD (r = 0.8, p 0.009) and Harvey-Bradshaw index (HBI, r = 0.76, p 0.04). For localizing active disease in the ileum, GIUS had a sensitivity of 93.7%, 80% for lesions in the right colon, 100% for transverse colon, and 89% for the left colon. Specificity was 100% for ileal and colonic lesions.

CONCLUSION

Loss of stratification, BWT, and Doppler activity in the bowel wall correlate with endoscopic and clinical disease activity in CD. GIUS is a sensitive modality in assessing disease activity in CD.

Use of Cross-Sectional Imaging for Tight Monitoring of Inflammatory Bowel Diseases

A treat-to-target strategy with close monitoring of intestinal inflammation is recommended in inflammatory bowel disease (IBD). Ileocolonoscopy remains the gold standard for assessing disease activity in IBD but is a relatively invasive procedure and is impossible to repeat in the context of tight monitoring strategies. In addition to biomarkers, cross-sectional imaging increasingly is used in these patients. Computed tomography is limited by the use of radiation, while the use of magnetic resonance enterography (MRE) is limited by its cost and access. There is growing interest in bowel ultrasound that represents a cost-effective, noninvasive, and well-tolerated modality in clinical practice, but it is operator dependent. Compared with ileocolonoscopy and MRE, bowel US has been shown to have the same level of accuracy in assessing and monitoring disease activity for both CD and UC and thus can be considered a point-of-care test. Diffusion-weighted imaging (DWI) is a MR imaging technique that increasingly is used in both IBD and non-IBD conditions and has been shown to be a valuable and accurate tool for assessing and monitoring IBD activity. Compared with conventional MRE, DWI is quicker, less time consuming, may not require intravenous contrast agent, fasting, bowel cleansing, oral preparation, or rectal preparation. This review discusses the role of these cross-sectional imaging techniques for the management of patients with IBD. In the near future, the value of DWI and ultrasound in assessing IBD will require further investigation in the era of transmural healing in CD and complete mucosal healing, including histologic remission, in ulcerative colitis.

Systematic Review: Patient Perceptions of Monitoring Tools in Inflammatory Bowel Disease

Background and Aims

Inflammatory bowel disease (IBD) is a lifelong disease requiring frequent assessment to guide treatment and prevent flares or progression. Multiple tools are available for clinicians to monitor disease activity; however, there are a paucity of data to inform which monitoring tools are most acceptable to patients. The review aims to describe the available evidence for patient preference, satisfaction, tolerance and/or acceptability of the available monitoring tools in adults with IBD.

Methods

Embase, Medline, Cochrane Central and Clinical Trials.gov were searched from January 1980 to April 2019 for all study types reporting on the perspectives of adults with confirmed IBD on monitoring tools, where two or more tools were compared. Outcome measures with summary and descriptive data were presented.

Results

In 10 studies evaluating 1846 participants, monitoring tools included venipuncture, stool collection, gastrointestinal ultrasound, computed tomography, magnetic resonance imaging, wireless capsule endoscopy, barium follow-through and endoscopy. Outcome domains were patient satisfaction, acceptability of monitoring tool and patient preference. Noninvasive investigations were preferable to endoscopy in nine studies. When assessed, gastrointestinal ultrasound was consistently associated with greater acceptability and satisfaction compared with endoscopy or other imaging modalities.

Conclusions

Adults with IBD preferred noninvasive investigations, in particular gastrointestinal ultrasound, as compared to endoscopy for monitoring disease activity. When assessing disease activity, patient perceptions should be considered in the selection of monitoring tools. Further research should address whether adpoting monitoring approaches considered more acceptable to patients results in greater satisfaction, adherence and ultimately more beneficial clinical outcomes.

Abdominal Imaging in pregnancy (maternal and foetal risks)

Imaging studies are useful in the diagnostic evaluation of inflammatory bowel diseases. However, concern often exists about the safety of imaging for pregnant and lactating women and their infants, leading to unwarranted avoidance of beneficial diagnostic tests or disruption of breastfeeding. Ultrasonography and magnetic resonance imaging (MRI) are not associated with ionizing radiation and are the imaging techniques of choice for pregnant patients. Safety of MRI contrast agent gadolinium in pregnancy is uncertain, therefore MRI without gadolinium should be performed. Intestinal ultrasound where available and MRI without gadolinium can be used to characterise disease complications such as bowel obstruction or intra-abdominal collections. Ionising radiation exposure through computed tomography (CT) is usually at much lower doses than those associated with foetal harm, however CT should be reserved for the rare clinical situations in which ultrasound and MRI are either unavailable or unable to provide the required diagnostic information.

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

Background and Aim

Point‐of‐care ultrasound (POCUS) is a noninvasive alternative to ileocolonoscopy for monitoring disease activity in inflammatory bowel disease (IBD) but is underutilized in practice. Accuracy data are needed to engender clinician confidence in POCUS and increase uptake. The aim of this study was to evaluate the accuracy of POCUS compared to ileocolonoscopy in detecting active disease and extent in patients with IBD.

Methods

A prospective, blinded study was performed at a single tertiary center in South Australia between May 2017 and May 2018. Consecutive patients with a formal diagnosis of IBD who underwent both POCUS and ileocolonoscopy within 30 days of one another, performed to evaluate IBD disease activity, were eligible for participation. The accuracy of POCUS compared to ileocolonoscopy was assessed using sensitivity, specificity, and Cohen's kappa coefficient analyses.

Results

A total of 74 patients were included in the final analysis, 35 (47%) of whom had Crohn's disease and 39 (53%) ulcerative colitis; 37 subjects (50%) underwent a POCUS and ileocolonoscopy on the same day. POCUS demonstrated 91% sensitivity and 83% specificity for detecting endoscopically active IBD, correlating with a positive predictive value (PPV) of 89%, a negative predictive value (NPV) of 86%, and a kappa coefficient of 0.74 (88%). POCUS defined disease extent with 87% sensitivity and 81% specificity, correlating with a PPV of 85% and NPV of 83% and a kappa coefficient of 0.70 (85%).

Conclusion

POCUS is accurate in defining disease activity and extent in IBD compared to ileocolonoscopy. POCUS represents an appealing, noninvasive alternative to ileocolonoscopy for monitoring disease activity in IBD.

Gastrointestinal ultrasound in inflammatory bowel disease care: Patient perceptions and impact on disease-related knowledge

Background and Aim

Objective monitoring of disease activity is integral to therapeutic decision-making in inflammatory bowel disease (IBD). Data are sparse on patients' perspectives of tools used to monitor disease activity in IBD. To evaluate patients' perspectives of gastrointestinal ultrasound (GIUS) performed during routine IBD clinical care, along with its impact on IBD-specific knowledge.

Methods

Patients with a formal diagnosis of IBD who underwent GIUS at two tertiary IBD services between March 2017 and January 2019 participated in this prospective study. Participants completed a questionnaire measuring the acceptability, tolerability, and usefulness of GIUS using a visual analogue scale (VAS) from 0 (disagree) to 10 (strongly agree). Comparative acceptability of IBD monitoring tools and the impact of GIUS on IBD-specific knowledge was measured.

Results

A total of 121 participants completed the questionnaire, with a mean age of 42 years (range 17-78), 54 (45%) males, and 79 (65%) Crohn's disease patients. In the overall population, GIUS was scored as highly acceptable for monitoring IBD (mean 9.20 ± 1.37) compared to colonoscopy (7.94 ± 2.30), stool sampling (8.17 ± 1.96), blood sampling (8.87 ± 1.62), and imaging (8.67 ± 1.60); P < 0.01 for each comparison. GIUS caused little patient discomfort (1.88 ± 1.83), and 98 (81%) participants ranked GIUS as their preferred IBD monitoring tool. GIUS also improved patients' overall IBD-specific knowledge (VAS IBD-specific knowledge 7.96 ± 1.92), including their understanding of the need for medical therapy and disease extent.

Conclusion

GIUS is a highly acceptable and well-tolerated tool for monitoring disease activity in IBD patients. GIUS is preferred by patients and enhances IBD-specific knowledge.

Usefulness of intestinal real-time virtual sonography in patients with inflammatory bowel disease

BACKGROUND AND AIM

Transabdominal ultrasonography (US) examination for the intestine is often difficult, and its precedence for intestinal examination depends on accessibility to experienced ultrasonographers. Real-time virtual sonography (RVS) assists examination of US as a fusion method by synchronizing US images with pre-captured computed tomography or magnetic resonance images. We aimed to evaluate the feasibility to use RVS for the examination of the intestine.

METHODS

The time to scan three parts of the intestine was compared between conventional US and RVS in seven participants without intestinal diseases. Whether RVS accurately synchronized US images with reference images of intestinal target lesions was judged in 20 patients with inflammatory bowel disease.

RESULTS

Examination time to scan the ascending colon and the ileocecum using intestinal RVS was significantly shorter than that using conventional US alone (36.7 vs 50.0 s [P = 0.0313] and 35.4 vs 66.4 s [P = 0.0156], respectively) in participants without intestinal diseases. Well-synchronized US images of the intestinal lesions, such as stenosis, with reference computed tomography/magnetic resonance images were obtained by RVS in all the lesions in the fixed parts of the colon (ascending and descending colon), and images of nine lesions in 12 lesions (75%) were well synchronized in the unfixed part of the intestine in Crohn's disease patients.

CONCLUSION

Real-time virtual sonography significantly reduced the examination time of intestinal US. Intestinal RVS can help the ultrasonographer to guide the US probe to detect and monitor intestinal lesions by synchronizing reference images, especially in inflammatory bowel disease patients (UMIN Clinical Trials Registry number: UMIN000011571).

Gastrointestinal ultrasound in inflammatory bowel disease: an underused resource with potential paradigm-changing application

Evolution of treatment targets in IBD has increased the need for objective monitoring of disease activity to guide therapeutic strategy. Although mucosal healing is the current target of therapy in IBD, endoscopy is invasive, expensive and unappealing to patients. GI ultrasound (GIUS) represents a non-invasive modality to assess disease activity in IBD. It is accurate, cost-effective and reproducible. GIUS can be performed at the point of care without specific patient preparation so as to facilitate clinical decision-making. As compared with ileocolonoscopy and other imaging modalities (CT and MRI), GIUS is accurate in diagnosing IBD, detecting complications of disease including fistulae, strictures and abscesses, monitoring disease activity and detecting postoperative disease recurrence. International groups increasingly recognise GIUS as a valuable tool with paradigm-changing application in the management of IBD; however, uptake outside parts of continental Europe has been slow and GIUS is underused in many countries. The aim of this review is to present a pragmatic guide to the positioning of GIUS in IBD clinical practice, providing evidence for use, algorithms for integration into practice, training pathways and a strategic implementation framework.

The role of intestinal ultrasound in diagnostics of bowel diseases

Intestinal ultrasound is a safe and inexpensive method that allows visualisation of the gastrointestinal tract and detection of abnormalities. This examination involves the use of two different ultrasound transducers: a low-frequency convex probe and high-frequency linear probe. When needed, the performance of these methods can be enhanced by the use of contrast media or Doppler techniques. Intestinal ultrasound is mostly utilised for the diagnosis and follow-up of patients with inflammatory bowel diseases, helping to avoid frequent use of invasive and expensive diagnostic procedures and leading to early implementation of suitable treatment. This technique can also serve to detect other pathologic conditions that are present in the gastrointestinal tract. It is a promising method with high sensitivity and specificity, which has gained popularity in recent years and has the potential to become the method of choice in the diagnostics of many intestinal disorders.

How to perform gastrointestinal ultrasound: Anatomy and normal findings

Gastrointestinal ultrasound is a practical, safe, cheap and reproducible diagnostic tool in inflammatory bowel disease gaining global prominence amongst clinicians. Understanding the embryological processes of the intestinal tract assists in the interpretation of abnormal sonographic findings. In general terms, the examination principally comprises interrogation of the colon, mesentery and small intestine using both low-frequency and high-frequency probes. Interpretation of findings on GIUS includes assessment of bowel wall thickness, symmetry of this thickness, evidence of transmural changes, assessment of vascularity using Doppler imaging and assessment of other specific features including lymph nodes, mesentery and luminal motility. In addition to B-mode imaging, transperineal ultrasonography, elastography and contrast-enhanced ultrasonography are useful adjuncts. This supplement expands upon these features in more depth.

Detection and characterization of murine colitis and carcinogenesis by molecularly targeted contrast-enhanced ultrasound

AIM

To study mucosal addressin cellular adhesion molecule-1 (MAdCAM-1) and vascular endothelial growth factor (VEGF)-targeted contrast enhanced ultrasound (CEUS) for the assessment of murine colitis and carcinogenesis.

METHODS

C57BL/6 mice were challenged with 3% dextran sodium-sulfate (DSS) for three, six or nine days to study the development of acute colitis. Ultrasound was performed with and without the addition of unspecific contrast agents. MAdCAM-1-targeted contrast agent was used to detect and quantify MAdCAM-1 expression. Inflammatory driven colorectal azoxymethane (AOM)/DSS-induced carcinogenesis was examined on day 42 and 84 using VEGF-targeted contrast agent. Highly specific tissue echogenicity was quantified using specialized software. Sonographic findings were correlated to tissue staining, western blot analysis and immunohistochemistry to quantify the degree of inflammation and stage of carcinogenesis.

RESULTS

Native ultrasound detected increased general bowel wall thickening that correlated with more progressed and more severe DSS-colitis (healthy mice: 0.3 mm ± 0.03 vs six days DSS: 0.5 mm ± 0.2 vs nine days DSS: 0.6 mm ± 0.2, P < 0.05). Moreover, these sonographic findings correlated well with clinical parameters such as weight loss (r² = 0.74) and histological damage (r² = 0.86) (P < 0.01). In acute DSS-induced murine colitis, CEUS targeted against MAdCAM-1 detected and differentiated stages of mild, moderate and severe colitis via calculation of mean pixel contrast intensity in decibel (9.6 dB ± 1.6 vs 12.9 dB ± 1.4 vs 18 dB ± 3.33, P < 0.05). Employing the AOM/DSS-induced carcinogenesis model, tumor development was monitored by CEUS targeted against VEGF and detected a significantly increased echogenicity in tumors as compared to adjacent healthy mucosa (healthy mucosa, 1.6 dB ± 1.4 vs 42 d, 18.2 dB ± 3.3 vs 84 d, 18.6 dB ± 4.9, P < 0.01). Tissue echogenicity strongly correlated with histological analysis and immunohistochemistry findings (VEGF-positive cells in 10 high power fields of healthy mucosa: 1 ± 1.2 vs 42 d after DSS start: 2.4 ± 1.6 vs 84 d after DSS start: 3.5 ± 1.3, P < 0.01).

CONCLUSION

Molecularly targeted CEUS is a highly specific and non-invasive imaging modality, which characterizes murine intestinal inflammation and carcinogenesis in vivo.

WFUMB Position Paper. Learning Gastrointestinal Ultrasound: Theory and Practice

Gastrointestinal ultrasound (GIUS) is an ultrasound application that has been practiced for more than 30 years. Recently, GIUS has enjoyed a resurgence of interest, and there is now strong evidence of its utility and accuracy as a diagnostic tool for multiple indications. The method of learning GIUS is not standardised and may incorporate mentorship, didactic teaching and e-learning. Simulation, using either low- or high-fidelity models, can also play a key role in practicing and honing novice GIUS skills. A course for training as well as establishing and evaluating competency in GIUS is proposed in the manuscript, based on established learning theory practice. We describe the broad utility of GIUS in clinical medicine, including a review of the literature and existing meta-analyses. Further, the manuscript calls for agreement on international standards regarding education, training and indications.

Current best practice for disease activity assessment in IBD

Therapeutic advances in the management of IBD have led to a paradigm shift in the assessment of IBD disease activity. Beyond clinical remission, objective assessment of inflammation is now critical to guiding subsequent therapy as part of a 'treat to target' strategy. Multiple domains of disease activity assessment in IBD exist, each of which has its merits, although none are perfect. The aim of this Review is to comprehensively evaluate measures of disease activity in both ulcerative colitis and Crohn's disease, including clinical, endoscopic, histological and radiological assessment tools, as well as the use of biomarkers and quality of life evaluation. A subjective appraisal of the best indices for use in clinical practice is provided, based on index validation, responsiveness and experience in clinical trials, international specialist opinion, and practicality and suitability for use in clinical practice. This Review aims to enable the reader to gain confidence in IBD disease activity assessment and to give ready access to the necessary tools.

Bowel Ultrasonography in the Management of Crohn's Disease. A Review with Recommendations of an International Panel of Experts

BACKGROUND

Bowel ultrasonography (US) is considered a useful technique for assessing mural inflammation and complications in Crohn's disease (CD). The aim of this review is to appraise the evidence on the accuracy of bowel US for CD. In addition, we aim to provide recommendations for its optimal use.

METHODS

Publications were identified by literature search from 1992 to 2014 and selected based on predefined criteria: 15 or more patients; bowel US for diagnosing CD, complications, postoperative recurrence, activity; adequate reference standards; prospective study design; data reported to allow calculation of sensitivity, specificity, agreement, or correlation values; articles published in English.

RESULTS

The search yielded 655 articles, of which 63 were found to be eligible and retrieved as full-text articles for analysis. Bowel US showed 79.7% sensitivity and 96.7% specificity for the diagnosis of suspected CD, and 89% sensitivity and 94.3% specificity for initial assessment in established patients with CD. Bowel US identified ileal CD with 92.7% sensitivity, 88.2% specificity, and colon CD with 81.8% sensitivity, 95.3% specificity, with lower accuracy for detecting proximal lesions. The oral contrast agent improves the sensitivity and specificity in determining CD lesions and in assessing sites and extent.

CONCLUSIONS

Bowel US is a tool for evaluation of CD lesions in terms of complications, postoperative recurrence, and monitoring response to medical therapy; it reliably detects postoperative recurrence and complications, as well as offers the possibility of monitoring disease progression.

Assessment of stricturing Crohn's disease: Current clinical practice and future avenues

Crohn’s disease (CD) is a chronic remittent idiopathic disease. Although the early phase of the disease is commonly characterized by inflammation-driven symptoms, such as diarrhea, the frequency of fibrostenotic complications in patients with CD increases over the long-term course of the disease. This review presents the current diagnostic options for assessing CD-associated strictures. In addition to the endoscopic evaluation of CD strictures, this review summarizes the currently available imaging modalities, including ultrasound and cross-sectional imaging techniques. In addition to stricture detection, differentiating between the primarily inflammatory strictures and the predominantly fibrotic ones is essential for selecting the appropriate treatment strategy (anti-inflammatory medical treatment vs endoscopical or surgical approaches). Therefore, recent imaging advances, such as contrast-enhanced ultrasound and ultrasound elastography, contribute to the development of non-invasive non-radiating imaging of CD-associated strictures. Finally, novel magnetic resonance imaging techniques, such as diffusion-weighted, motility and magnetization transfer imaging, as well as ¹⁸F-FDG PET/CT, molecular imaging approaches and biomarkers, are critically reviewed with regard to their potential role in assessing stricturing CD.