Role of US in detection of Crohn disease: meta-analysis

Review article: A practical approach to persistent gastrointestinal symptoms in inflammatory bowel disease in remission

BACKGROUND

Persistent gastrointestinal symptoms are prevalent in adult patients with inflammatory bowel disease (IBD), even when endoscopic remission is reached. These symptoms can have profound negative effects on the quality of life of affected patients and can be difficult to treat. They may be caused by IBD-related complications or comorbid disorders, but they can also be explained by irritable bowel syndrome (IBS)-like symptoms.

AIMS

To provide a practical step-by-step guide to diagnose and treat persistent gastrointestinal symptoms in patients with IBD in remission via a personalised approach.

METHODS

We scrutinised relevant literature on causes, diagnostics and treatment of persistent gastrointestinal symptoms (abdominal pain or discomfort, bloating, abdominal distension, diarrhoea, constipation and faecal incontinence) in patients with IBD in remission.

RESULTS

A graphical practical guide for several steps in diagnosing, identifying potential triggers and adequate treatment of persistent gastrointestinal symptoms in IBD in remission is provided based on supporting literature. The first part of this review focuses on the diagnostic and treatment approaches for potential IBD-related complications and comorbidities. The second part describes the approach to IBS-like symptoms in IBD in remission.

CONCLUSIONS

Persistent gastrointestinal symptoms in IBD in remission can be traced back to potential pathophysiological mechanisms in individual patients and can be treated adequately. For both IBD-related complications and comorbidities and IBS-like symptoms in IBD in remission, pharmacological, dietary, lifestyle or psychological treatments can be effective. A systematic and personalised approach is required to reduce the burden for patients, healthcare systems, and society.

Determining the Accuracy of Intestinal Ultrasound Scores as a Prescreening Tool in Crohn's Disease Clinical Trials

INTRODUCTION

High rates of screen failure for the minimum Simple Endoscopic Score for Crohn's Disease (SES-CD) plague Crohn's disease (CD) clinical trials. We aimed to determine the accuracy of segmental intestinal ultrasound (IUS) parameters and scores to detect segmental SES-CD activity.

METHODS

A single-center, blinded, cross-sectional cohort study of children and young adult patients with CD undergoing IUS and ileocolonoscopy, comparing segmental IUS bowel wall thickness (BWT), hyperemia (modified Limberg score [MLS]), and scores to detect segmental SES-CD activity: (i) SES-CD ≤2, (ii) SES-CD ≥6, and (iii) SES-CD ≥4 in the terminal ileum (TI) only. Primary outcome was accuracy of BWT, MLS, and IUS scores to detect SES-CD ≤2 and SES-CD ≥6. Secondary outcomes were accuracy of TI BWT, MLS, and IUS scores to detect SES-CD ≥4 and correlation with the SES-CD.

RESULTS

Eighty-two patients (median [interquartile range] age 16.5 [12.9-20.0] years) underwent IUS and ileocolonoscopy of 323 bowel segments. Segmental BWT ≤3.1 mm had a similar high accuracy to detect SES-CD ≤2 as IUS scores (area under the receiver operating curve [AUROC] 0.833 [95% confidence interval 0.76-0.91], 94% sensitivity, and 73% specificity). Segmental BWT ≥3.6 mm and ≥4.3 mm had similar high accuracy to detect SES-CD ≥6 (AUROC 0.950 [95% confidence interval 0.92-0.98], 89% sensitivity, 93% specificity) in the colon and an SES-CD ≥4 in the TI (AUROC 0.874 [0.79-0.96], 80% sensitivity, and 91% specificity) as IUS scores. Segmental IUS scores strongly correlated with the SES-CD.

DISCUSSION

Segmental IUS BWT is highly accurate to detect moderate-to-severe endoscopic inflammation. IUS may be the ideal prescreening tool to reduce unnecessary trial screen failures.

Non-traumatic lower abdominal pain: ultrasonographic and clinical differential diagnosis

Lower abdominal pain is frequently reported and has a diverse differential diagnosis. In cases with atypical presentation and nonspecific findings, further imaging evaluation is required to confirm the clinical suspicion and to distinguish between self-limiting disorders and those requiring immediate intervention. In line with European guidelines, transabdominal ultrasonography is recommended as a first-line imaging modality for clinically suspected acute appendicitis and acute diverticulitis, which respectively represent the predominant causes of right and left lower quadrant abdominal pain. It is similarly the preferred method for evaluating suspected obstetric/gynecologic and genitourinary diseases. Computed tomography is utilized as a secondary option when ultrasonography results are inconclusive. This pictorial essay illustrates the sonographic features of the most common conditions associated with lower abdominal pain and outlines the clinical characteristics of each entity.

Echopattern parameter as an aid to profile Crohn's disease patients

BACKGROUND

Intestinal ultrasonography (US) allows for the characterization of the intestinal lesions and provides information on transmural inflammation. The aim of the study was to assess the clinical relevance of echopattern and correlation with Crohn's disease (CD) behavior and activity.

METHODS

We performed a prospective study including CD patients assessed by intestinal US. The echopattern was classified as hypoechoic, hyperechoic and stratified. Color-doppler US was also performed in the thickest segment.

RESULTS

One hundred CD patients were enrolled. The hypoechoic echopattern was significantly correlated with penetrating behavior (r = 0.44, p<0.0001), active disease (r = 0.21, p = 0.034), C-reactive protein/Fecal Calprotectin (r = 0.31, p = 0.004; r = 0.34, p = 0.031, respectively) and steroids (r = 0.33, p = 0.0008). Hypoechoic echopattern was associated with younger age than stratified (p = 0.046) and hyperechoic (p = 0.018) echopatterns. Bowel wall thickness was greater in the hypoechoic group than in the hyperechoic/stratified groups (p = 0.011 and p<0.0001, respectively). Hypoechoic echopattern was associated with fistulas (r = 0.52, p<0.0001) and increased vascularization (r = 0.32, p = 0.001). The hyperechoic echopattern showed a significant correlation with stricturing disease and an inverse correlation with fistulas. During a follow up period of 6 months, patients with hypoechoic echopattern had an increased risk of biological therapy need or surgery.

CONCLUSIONS

The characterization of bowel wall echopattern allows for the identification of different CD behaviors.

Small Bowel Imaging in Celiac Disease: Is there a role for Small Bowel Ultrasound?

PURPOSE OF REVIEW

The incidence of celiac disease (CD) has increased over the last decades in part due to better disease awareness. Small bowel ultrasound (sb US) enables dynamic assessment of the bowel; although this topic has been addressed, the use of sb US in the diagnosis and in the follow-up of CD patients is limited to a few specialized tertiary referral centers. Herein, we aimed at summarizing the available literature on this topic to better define the potential clinical implications of sb US in CD, also through a comparison with other available diagnostic techniques.

RECENT FINDINGS

According to available data, sb US can be of help in confirming or excluding CD in patients with clinical suspicion; specifically, the finding of increased gall bladder volume, free abdominal fluid and enlargement of mesenteric lymph nodes reliably and accurately predicts the diagnosis of CD, whereas the absence of bowel dilatation and increased peristalsis may exclude the diagnosis. However, the place of intestinal US in the diagnostic algorithm of CD is likely to vary depending on the probability of the disease in a given population. There are only a few studies on the role of sb US in complicated CD, even if recent reports suggest a possible clinical role. There is a lack of data on follow-up of CD patients, particularly with the aim of detecting a poor diet adherence. According to current data sb US parameters have been shown to be of value in confirming and excluding the diagnosis of CD. Prospective studies with large sample size are warranted to determine whether to include sb US in the available guidelines for CD diagnosis and monitoring.

Relevance of sonographic parameters for inflammatory bowel disease in children

PURPOSE

Intestinal ultrasound (IUS) is widely used as the first exam in patients with suspected inflammatory bowel disease (IBD). This study investigated the accuracy of several IUS parameters, including increased bowel wall thickening (BWT), in detecting IBD in a paediatric population.

METHODS

The study included an unselected series of 113 patients aged 2-18 years (mean age 10.8 years, 65 male), referred for recurrent abdominal pain or altered bowel habits, without known organic diseases, to perform an IUS as first investigation of a diagnostic workup. Patients with full systematic IUS examination, clinical and biochemical exams, and ileocolonoscopy or an uneventful follow-up at least one year follow up were eligible.

RESULTS

23 IBD patients (20.4%; 8 ulcerative colitis, 12 Crohn's disease and 3 indeterminate colitis) were diagnosed. We found that increased BWT > 3 mm (OR 5.4), altered IUS bowel pattern (IUS-BP, OR 9.8) and mesenteric hypertrophy (MH, OR 5.2) accurately identified IBD at the multivariate analysis. IUS-BP, MH and BWT > 3 mm had a sensitivity of 78.3%, 65.2% and 69.6% and a specificity of 93.3%, 92.2% and 96.7%, respectively. The combination of these three alterations increased the specificity up to 100%, whilst decreased sensitivity to 56.5%.

CONCLUSION

Among several US parameters suggestive of IBD, the increased BWT, MH and altered echopattern are independent predictors of IBD. The ultrasonographic diagnosis of IBD could be more accurate if relied on combination of different sonographic parameters, than on the sole BWT evaluation.

The Role of Noninvasive Surrogates of Inflammation in Monitoring Pediatric Inflammatory Bowel Diseases: The Old and the New

Effectiveness of limited available therapies for pediatric inflammatory bowel disease has reached stagnation. Previous non-invasive monitoring strategies have relied upon cumbersome tools to evaluate clinical symptoms and biochemical markers that do not reflect endoscopic activity or respond quickly to treatments. Novel, patient-centric, and highly accurate, monitoring strategies with a focus on intestinal ultrasound for a direct, precise monitoring of activity to achieve disease modification are now possible. Ultimately, research on the optimal tight control monitoring strategies, individualized to each pediatric inflammatory bowel disease patient, are in development and offer a hope to potential therapeutic ceiling breakthrough on the horizon.

Sonographic evaluation of a surgically created pouch

This manuscript focuses on a review of the normal and abnormal sonographic appearance of the surgically created pouch as part of an article series on the topic. It includes information regarding sonographic technique, normal anatomy, and commonly encounter diseases and complications.

Assessment of Ileal Crohn's Disease Activity by Gastrointestinal Ultrasound and MR Enterography: A Pilot Study

INTRODUCTION

In some cases, there may be a discrepancy between the symptomatology alleged by Crohn's disease (CD) patients and the results of laboratory tests or imaging investigations. Ileocolonoscopy with biopsy is the primary investigation for diagnosing and monitoring CD patients. Cross-sectional imaging techniques such as CT or MR enterography (MRE) and intestinal ultrasonography (IUS) have been proposed as complementary methods to colonoscopy for a complete evaluation of this category of patients. This study aims to identify the role of IUS, contrast-enhanced ultrasound (CEUS) and MRE in evaluating ileal CD activity, using clinical severity scores (Crohn's disease activity index-CDAI, Harvey-Bradshaw index-HBI) and faecal calprotectin or C-reactive protein (CRP) levels as reference methods.

MATERIALS AND METHODS

A total of 44 adult patients with ileal CD confirmed using an ileocolonoscopy with biopsy and histopathological examination were assessed by IUS, CEUS and MRE. The evaluation of the disease activity based on the results obtained from the cross-sectional imaging tests was carried out by using some severity scores available in the literature. The sensitivity and specificity of IUS + CEUS and MRE for differentiating active from inactive forms of CD were determined using CDAI, HBI, faecal calprotectin and CRP as reference methods. The accuracy of the results was assessed by the receiver operating characteristics method. The Pearson correlation coefficient was used to determine the types of correlation. A p-value less than 0.05 suggested a statistically significant relationship.

RESULTS

Compared to CDAI, the best correlation was identified for Limberg score (r = 0.667, 95% confidence interval (CI) [0.46, 0.8], p < 0.001), followed by MaRIAs score (r = 0.614, 95% CI [0.39, 0.77], p < 0.001). A sensitivity of 93.33% and a specificity of 71.43% (AUC = 0.98) were demonstrated in the case of Limberg score for differentiating patients with active disease from those in remission and for MaRIAs score a sensitivity of 100.00% and a specificity of 57.14% (AUC = 0.97). Regarding HBI, the best correlation was observed for MaRIAs score (r = 0.594, 95% CI [0.36, 0.76], p < 0.001). Also, faecal calprotectin showed the best correlation with MaRIAs score (r = 0.697, 95% CI [0.46, 0.84], p < 0.001), but in the case of CRP, there was only a weak correlation for all evaluated scores.

CONCLUSIONS

Although magnetic resonance imaging does not appear to be superior to ultrasonography in terms of accuracy for differentiating active forms of CD from those in remission, the results of our study suggest that MRE associates a better correlation with clinical severity scores and faecal calprotectin levels compared to ultrasonography. More studies are needed to validate these results.

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.

Basic practices for gastrointestinal ultrasound

The standard diagnostic modalities for gastrointestinal (GI) diseases have long been endoscopy and barium enema. Recently, trans-sectional imaging modalities, such as computed tomography and magnetic resonance imaging, have become increasingly utilized in daily practice. In transabdominal ultrasonography (US), the bowel sometimes interferes with the observation of abdominal organs. Additionally, the thin intestinal walls and internal gas can make structures difficult to identify. However, under optimal US equipment settings, with identification of the sonoanatomy and knowledge of the US findings of GI diseases, US can be used effectively to diagnose GI disorders. Thus, the efficacy of GIUS has been gradually recognized, and GIUS guidelines have been published by the World Federation for Ultrasound in Medicine and Biology and the European Federation of Societies for Ultrasound in Medicine and Biology. Following a systematic scanning method according to the sonoanatomy and precisely estimating the layered wall structures by employing color Doppler make diagnosing disease and evaluating the degree of inflammation possible. This review describes current GIUS practices from an equipment perspective, a procedure for systematic scanning, typical findings of the normal GI tract, and 10 diagnostic items in an attempt to help medical practitioners effectively perform GIUS and promote the use of GIUS globally.

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.

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.

Exploring the concept of deep remission in Crohn's disease: correlation between transmural healing and biomarkers

BACKGROUND

While mucosal healing (MH) and transmural healing (TH) predict relevant clinical outcomes in Crohn's disease (CD), little is known about the real significance and clinical impact of deep remission (DR).

OBJECTIVES

To better explore the concept of DR, toward a direct correlation between MH, TH, and biomarkers.

DESIGN

Real-world observational longitudinal study to evaluate the rate of clinical remission (CR), MH and TH, and the fecal calprotectin (FC)/C-reactive protein (CRP) levels in all consecutive CD patients on biologics.

METHODS

A receiver operating characteristic (ROC) curve was constructed to define the best FC and CRP cut-offs associated with MH and TH. Finally, patients achieving CR, MH, and TH, in association with the target FC/CRP values, were considered in DR.

RESULTS

Among 118 CD patients, CR, MH, and TH were achieved in 62.7, 44.1, and 32.2%, respectively. After 2 years, the mean FC levels decreased from 494 ± 15.4 μg/g to 260 ± 354.9 μg/g (p < 0.01). Using the ROC curve analysis, an FC cut-off value of 94 μg/g was associated with both MH [sensitivity: 94.2%, specificity: 84.8%, positive predictive value (PPV): 83.05%, negative predictive value (NPV): 94.92%, area under the curve (AUC): 0.95] and TH (sensitivity: 92.1%, specificity: 70%, PPV: 64.4%, NPV: 94.9%, AUC: 0.88). CRP < 5 mg/L was associated with both MH (sensitivity: 96.1%, specificity: 62.1%, PPV: 66.7%, NPV: 95.35%, AUC: 0.85) and TH (sensitivity: 97.4%, specificity: 52.5%, PPV: 52%, NPV: 95.35%, AUC: 0.78). When considering CD patients with concomitant CR, MH, and TH associated with an FC < 94 μg/g and CRP < 5 mg/L, this association was found identified in 33 patients (27.9%).

CONCLUSION

An FC < 94 μg/g and a normal CRP are associated with CR, MH, and TH and could be included in the definition of DR in association. So by definition, DR could be achieved in approximately 30% of CD patients during maintenance treatment with biologics.

Capsule enteroscopy versus small-bowel ultrasonography for the detection and differential diagnosis of intestinal diseases

Background/Aims

Capsule enteroscopy (CE) and intestinal ultrasonography (IUS) are techniques that are currently used for investigating small-bowel (SB) diseases. The aim of this study was to compare the main imaging findings and the lesion detection rate (LDR) of CE and IUS in different clinical scenarios involving the SB.

Methods

We retrospectively enrolled patients who underwent CE and IUS for obscure gastrointestinal bleeding (OGIB), complicated celiac disease (CeD), and suspected or known inflammatory bowel disease (IBD). We evaluated the LDR of both techniques. The accuracy of IUS was determined using CE as the reference standard.

Results

A total of 159 patients (113 female; mean age, 49±19 years) were enrolled. The LDR was 55% and 33% for CE and IUS (p<0.05), respectively. Subgroup analysis showed that the LDR of CE was significantly higher than that of IUS in patients with OGIB (62% vs. 14%, p<0.05) and CeD (55% vs. 35%, p<0.05). IUS showed a similar LDR to CE in patients with suspected or known IBD (51% vs. 46%, p=0.83).

Conclusions

CE should be preferred in cases of OGIB and CeD, whereas IUS should be considered an early step in the diagnosis and follow-up of IBD even in patients with a proximal SB localization of the disease.

David Against Goliath: Direct Comparison of Handheld Bowel Sonography and Magnetic Resonance Enterography for Diagnosis of Crohn's Disease

BACKGROUND

Diagnosis of Crohn's disease (CD) requires ileo-colonoscopy (IC) and cross-sectional evaluation. Recently, "echoscopy" has been used effectively in several settings, although data about its use for CD diagnosis are still limited. Our aim was to evaluate the diagnostic accuracy of handheld bowel sonography (HHBS) in comparison with magnetic resonance enterography (MRE) for CD diagnosis.

METHODS

From September 2019 to June 2021, we prospectively recruited consecutive subjects attending our third level IBD Unit for suspected CD. Patients underwent IC, HHBS, and MRE in random order with operators blinded about the result of the other procedures. Bivariate correlation between MRE and HHBS was calculated by Spearman coefficient (r). To test the consistency between MRE and HHBS for CD location and complications, the Cohen's k measure was applied.

RESULTS

Crohn's disease diagnosis was made in 48 out of 85 subjects (56%). Sensitivity, specificity, positive predictive values, and negative predictive values for CD diagnosis were 87.50%, 91.89%, 93.33%, and 85% for HHBS; and 91.67%, 94.59%, 95.65%, and 89.74% for MRE, without significant differences in terms of diagnostic accuracy (89.41% for HHBS vs 92.94% for MRE, P = NS). Magnetic resonance enterography was superior to HHBS in defining CD extension (r = 0.67; P < .01) with a better diagnostic performance than HHBS for detecting location (k = 0.81; P < .01), strictures (k = 0.75; P < .01), abscesses (k = 0.68; P < .01), and fistulas (k = 0.65; P < .01).

CONCLUSION

Handheld bowel sonography and MRE are 2 accurate and noninvasive procedures for diagnosis of CD, although MRE is more sensitive in defining extension, location, and complications. Handheld bowel sonography could be used as effective ambulatory (or out-of-office) screening tool for identifying patients to refer for MRE examination due to high probability of CD diagnosis.

The value of multi-modes of ultrasound in evaluating segmental mucosal healing in patients with Crohn's disease

BACKGROUND

Mucosal healing, the result of endoscopic remission, is associated with prolonged clinical remission and delayed deterioration of Crohn's disease, which is significant and accompanied by reduced hospitalizations and surgeries. Currently, the relationship between ultrasonic parameters and mucosal healing remains controversial. To establish an ultrasonic regression model to evaluate mucosal healing, we conducted this preliminary study using multiple parameters from B-mode ultrasonography, colour Doppler flow imaging and shear wave elastography systematically.

METHODS

This study consisted of two single-centre investigations based on development and validation populations who received endoscopies (as the gold standard) and ultrasound. The involved bowel segments were divided into mucosal healing (MH) and nonmucosal healing (NMH) groups according to endoscopic results. Eight ultrasonic parameters were observed, including bowel wall thickness (BWT), mesenteric fat thickness (MFT), median modulus of elasticity (Emean), average shear wave velocity (SWV), Limberg scoring (LG), bowel wall stratification (BWS), ascites (AS) and lymph node enlargement (LN). We developed an ultrasonic regression model in the development phase to evaluate segmental mucosal healing and undertook prospective validation of this model.

RESULTS

A total of 124 patients with 380 involved bowel segments from the development and validation cohorts were evaluated. Eight ultrasonic parameters were significantly different between the two groups (P<0.05) in the development phase. Four significant parameters with better AUC performance were selected to establish an ultrasonic regression model to predict mucosal healing. The AUCs of this ultrasonic model were 0.975 and 0.942 in the development and validation cohorts, respectively.

CONCLUSION

The multimodal ultrasonic model has the potential to evaluate segmental mucosal healing in Crohn's disease.

Bleeding per rectum in pediatric population: A pictorial review

Bleeding per rectum in children can be seen in congenital as well as acquired conditions that may require medical or surgical management. The present review article is aimed to discuss the imaging findings of some common and uncommon causes of bleeding per rectum in children.

Bleeding per rectum in pediatric population: A pictorial review

Bleeding per rectum in children can be seen in congenital as well as acquired conditions that may require medical or surgical management. The present review article is aimed to discuss the imaging findings of some common and uncommon causes of bleeding per rectum in children.

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.

Predictive Value of Bowel Ultrasound in Crohn's Disease: A 12-Month Prospective Study

BACKGROUND & AIMS

Mucosal healing is associated with better outcomes in Crohn's disease (CD). Colonoscopy is invasive and poorly tolerated. Bowel ultrasound (US) is a noninvasive tool that increasingly is being used for CD assessment. We assessed the predictive role of baseline bowel US findings on disease course in a large prospective cohort of CD patients for 12 months.

METHODS

Ileocolonic CD consecutive patients were followed up for 12 months after performing bowel US. The negative course of CD, defined as the need for steroids and/or change of therapy and/or hospitalization and/or the need for surgery, was assessed. We evaluated this composite end point and subsequently considered each individual end point separately. Predictors of negative disease course were analyzed by logistic regression analysis.

RESULTS

There were 225 ileal and/or colonic CD consecutive patients included in the study. We analyzed the association between baseline bowel US parameters and endoscopic activity (defined as a Simplified Endoscopic Activity score for CD > 2) to set up a noninvasive quantitative ultrasound-based score (bowel ultrasound score). The multivariable analysis identified the following independent predictors of a worse outcome throughout the 12-month period as follows: bowel ultrasound score greater than 3.52 (odds ratio [OR], 6.97; 95% CI, 2.87-16.93; P < .001), presence of at least 1 disease complication (stricture, fistula, abscess) at baseline bowel US (OR, 3.90; 95% CI, 1.21-12.53; P = .021), fecal calprotectin value of 250 μg/g or greater at baseline (OR, 5.43; 95% CI, 2.25-13.11; P < .001), and male sex (OR, 2.60; 95% CI, 1.12-6.02; P = .025).

CONCLUSIONS

Bowel US predicts the 12-month course in CD.

Evolving Short- and Long-Term Goals of Management of Inflammatory Bowel Diseases: Getting It Right, Making It Last

Short- and long-term treatment targets in inflammatory bowel diseases (IBDs) evolved during the last decade, shifting from symptom control to endoscopic healing and patient-centered parameters. The STRIDE-II consensus placed these targets on a timeline from initiating treatment and introduced additional targets, normalization of serum and fecal biomarkers, restoration of quality of life, prevention of disability, and, in children, restoration of growth. Transmural healing in Crohn's disease and histologic healing in ulcerative colitis currently serve as adjunct measures to gauge remission depth. However, whether early treatment according to a treat-to-target paradigm affects the natural course of IBD remains unclear, leading to the need for prospective disease-modification trials. The SPIRIT consensus defined the targets for these trials to assess the long-term impact of early treatment on quality of life, disability, disease complications, risk of neoplastic lesions, and mortality. As further data emerge about the risk-benefit balance of aiming toward deeper healing, the targets in treating IBDs may continue to shift.

Intestinal ultrasonography and fecal calprotectin for monitoring inflammation of ileal Crohn's disease: two complementary tests

Background/Aims

Tight control of inflammation and adjustment of treatment if activity persists is the current strategy for the management of Crohn’s disease (CD). The usefulness of fecal calprotectin (FC) in isolated involvement of the small intestine in CD is controversial. To assess the usefulness of FC to determine the inflammatory activity detected by intestinal ultrasonography (IUS) in ileal CD.

Methods

Patients with exclusively ileal involvement CD who underwent IUS and an FC were prospectively included. Simple ultrasound index was used to determine inflammatory activity. The usual statistical tests for comparison of diagnostic techniques were used.

Results

One hundred and five patients were included, IUS showed inflammatory activity in 59% of patients and complications in 18.1%. FC showed a significant correlation with IUS in the weak range (Spearman coefficient r=0.502; P<0.001); the area under the receiver operating characteristic curve was 0.79 (95% confidence interval, 0.70–0.88; P<0.001). The FC value that best reflected the activity in IUS was 100 μg/g with sensitivity, specificity, and positive and negative predictive values of 73.0%, 71.4%, 79.3% and 63.8%, respectively. There were no differences in FC concentration between patients with or without transmural complications. The addition of serum C-reactive protein to FC did not improve the ability to assess IUS activity.

Conclusions

FC has a significant correlation with IUS to monitor ileal CD activity. This correlation is weak and it does not allow assessing the presence of CD complications. Both tests should be used in conjunction for tight control of ileal CD. More studies on noninvasive tests in this location are needed.

The Use of Transabdominal Ultrasound in Inflammatory Bowel Disease

Transabdominal ultrasound (TAUS) is useful in all aspects of lesion screening, monitoring activity, or treating/diagnosing any related complications of inflammatory bowel disease. Its ability to screen or diagnose complications is almost the same as that of other methods, such as CT or MRI. Moreover, its noninvasiveness makes it a first-line examination method. A TAUS image depicting ulcerative colitis will show large intestinal wall thickening that is continuous from the rectum, which is mainly due to mucosal layer thickening, while for Crohn’s disease, a TAUS image is characterized by a diversity in the areas affected, distribution, and layer structure. Indicators of activity monitoring include wall thickness, wall structure, and vascular tests that use Doppler ultrasound or contrast agents. While all of these have been reported to be useful, at this time, no single parameter has been established as superior to others; therefore, a comprehensive evaluation of these parameters is justified. In addition, evaluating the elasticity of lesions using elastography is particularly useful for distinguishing between fibrous and inflammatory stenoses. However, the lack of objectivity is the biggest drawback of using ultrasound. Standardizing and popularizing the ultrasound process will be necessary, including scanning methods, equipment settings, and image analysis.

Crohn's Disease Activity Evaluation by Transabdominal Ultrasonography: Correlation with Double-Balloon Endoscopy

OBJECTIVES

Transabdominal ultrasonography (US) has been reported as a useful tool for evaluating Crohn's disease (CD) activity. Endoscopic findings and Crohn's disease activity index (CDAI) are currently considered the gold standard for assessing CD activity. We assessed the correlation between US and double-balloon endoscopy (DBE), and CDAI for evaluating CD activity.

METHODS

We analyzed patients with CD undergoing US and DBE within 10 days between the procedures. The intestine was divided into four segments and analyzed by the US scoring system (US-CD) and the simple endoscopic score for Crohn's disease (SES-CD). CDAI was compared with US-CD and SES-CD. Spearman's rank correlation coefficient was used for statistical analysis.

RESULTS

Twenty-five patients with CD (11 women, 14 men; mean age 35.4 ± 14.9 years, range 16-65 years) were enrolled. Twenty-four patients received antitumor necrosis factor inhibitor therapy. CDAI was 128.1 (range 36-227). A significant moderate correlation was found between the US-CD and SES-CD in all segments (ρ = .64, P < .01). The US-CD showed a strong correlation with CDAI (ρ = .78, P < .01), whereas the SES-CD showed a moderate correlation (ρ = .55, P < .05).

CONCLUSIONS

US-CD and SES-CD showed a moderate correlation for assessing CD activity. US-CD showed a stronger correlation with CDAI than SES-CD, suggesting that US could more accurately evaluate the disease activity.

Prognostic value of ultrasound activity and parietal healing in patients with Crohn's disease

INTRODUCTION

the "treat to target" strategy for the management of patients with Crohn's disease (CD) requires simple, reliable and non-invasive tools for continuous monitoring of the disease. Intestinal ultrasound has been proposed as an emerging technique that could be very useful in this field.

MATERIAL AND METHODS

patients who had undergone an intestinal ultrasound in the clinical practice between February 2013 and October 2018 at our hospital were retrospectively included. The evolution of the patients during follow-up was assessed based on the presence of ultrasound activity and the therapeutic changes based on the results.

RESULTS

two hundred and seventy-seven CD patients were included and the median follow-up time was 24 months (range 5-73 months). Signs of ultrasound inflammatory activity were identified in 166 patients (60 %), and of them, treatment was escalated in 116 patients (70 %) based on the results of the ultrasound. Among patients with identified ultrasound activity, in 166 patients (60 %) the evolution was less favorable than in those without activity, with a shorter time until the next outbreak. Thus, the median disease-free survival (without outbreaks) after performing the ultrasound was 18 months when ultrasound activity was identified (although in most of the patients [70 %] the treatment had been escalated) vs 47 months in patients without ultrasound activity. However, these differences were not statistically significant (p < 0.0001). Among the 111 patients without ultrasound activity, those who achieved "parietal healing" (74 patients) had a better evolution with a 12 % subsequent outbreak vs 27 % during follow-up (p = 0.05). Thus, 15 % of patients with parietal healing had an outbreak vs 34 % of those who had not normalized the ultrasound findings after three years of follow-up.

CONCLUSION

intestinal ultrasound is a technique capable of detecting inflammatory activity in patients with Crohn's disease and the presence of ultrasound activity is a risk factor for a new outbreak of activity and/or clinical relapse. Likewise, the presence of "parietal or transmural healing" (PH) is associated with a better evolution of patients during follow-up. Thus, it could be a more precise objective to consider deep remission in CD, with intestinal ultrasound being a useful technique for this purpose.

Diagnostic performance of magnetic resonance enterography and ultrasound in children with inflammatory bowel diseases: a diagnostic test accuracy meta-analysis

OBJECTIVES

Magnetic resonance enterography (MRE) and ultrasound (US) can be used to diagnose inflammatory bowel diseases (IBD) in children. This meta-analysis aimed to determine the diagnostic performance of MRE and US in pediatric patients with IBD.

METHODS

PubMed, Embase, and the Cochrane Library were searched for eligible studies published up to June 1, 2020. The outcomes were the performances of MRE and US at the segment and patient levels. Pooled sensitivity, specificity, positive and negative likelihood ratios (PLR and NLR), diagnostic odds ratio (DOR), and the area under the summary receiver operating characteristic curves value (SROC) were analyzed.

RESULTS

Eight studies (340 children) were included. Compared with the reference standard, MRE showed pooled sensitivity of 93.0% (95% confidence interval (CI): 90.0-95.4%), specificity of 94.6% (95% CI: 92.1-96.5%), PLR of 11.146 (95% CI: 5.027-24.713), NLR of 0.094 (95% CI: 0.057-0.155), and DOR of 134.21 (95% CI: 40.72-442.29), with a SROC of 0.9721. Similar results were observed at the patient and segment levels. Compared with the reference standard, US had pooled sensitivity of 84.1% (95% CI: 69.9-93.4%), specificity of 82.9% (95% CI: 66.4-93.4%), PLR of 4.924 (95% CI: 2.351-10.310), NLR of 0.207 (95% CI: 0.103-0.413), and DOR of 25.919 (95% CI: 7.63-88.07), but only two studies were included. US (reader 1) had a similar diagnostic value to US (reader 2).

CONCLUSIONS

The present meta-analysis shows that MRE has good performance in detecting IBD in pediatric patients. Only two studies used US, and additional studies are necessary to confirm the diagnostic performance of US for IBD in children.

KEY POINTS

• MRE has good performance in the detection of IBD in pediatric patients. • Similar results were observed at the patient and segment levels for MRE. • Only two studies were included for US, without differentiating patient/segment.

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.

Using shear wave elasticity in normal terminal ileum of a healthy southwest Chinese population: a pilot study of reference elasticity ranges

Background

Elastography has not been widely applied to the gastrointestinal tract. The bowel wall's normal elasticity values are still unknown and are necessary for studies of gastrointestinal diseases. This study explores the feasibility of using shear wave elastography (SWE) to measure the terminal ileum wall stiffness in healthy subjects and establish the corresponding normal ranges of elasticity values.

Methods

This observational study recruited 139 healthy adult volunteers from April to July 2020. All examinations were performed in the anterior terminal ileum wall. Shear wave velocity (SWV) and Young's modulus (E) values were measured in the midline on longitudinal sections and replicated different operators' obtained data. Also, bowel wall thickness (BWT) and depth were recorded. Subgroups were classified according to the volunteers' gender, age, body mass index (BMI), BWT, and depth. The intra-class correlation coefficient was calculated to analyze inter- and intra-operator consistency, and independent t-tests and one-way analysis of variance were used to explore the differences in variables.

Results

The inter- and intra-operator agreements were good to excellent by different operators and in the replicated measurements (intra-operator consistency: 0.963; inter-operator consistency: 0.842). In all volunteers, the mean SWV was 1.08±0.25 m/s, the mean E value was 3.84±1.84 kPa, and the median BWT was 2 mm. SWV and E did not show significant differences according to gender (P=0.589), age (P=0.738), BMI (P=0.678), depth (P=0.375), or BWT (P=0.410). BWT did not show significant differences according to age (P=0.142), BMI (P=0.863), or depth (P=0.368).

Conclusions

SWE can be used in terminal ileum wall stiffness measurements with good reliability, and the SWE values do not appear to vary significantly according to different physiological factors. The corresponding elasticity ranges of the terminal ileum in normal adults were acquired.

Usefulness of a finger-mounted tissue oximeter with near-infrared spectroscopy for evaluating the intestinal oxygenation and viability in rats

PURPOSE

To investigate the utility of the device for evaluating intestinal oxygenation and viability using an animal model.

METHODS

Sprague-Dawley rats underwent laparotomy under general anesthesia, and the blood vessels in the terminal ileum were clamped to create ischemia. We measured the regional tissue oxygenation saturation (rSO2) using an oximeter after 1, 3, and 6 h of vessel clamping. Ischemic tissue damage was assessed using a histological score. The intestine was reperfused after each clamping period, and intestinal rSO2 and survival rate were evaluated.

RESULTS

When reperfusion was performed at 1 and 3 h after ischemia, rSO2 increased after 10 min, and it improved to the same level as for normal intestine after 1 h; all rats survived for 1 week. In contrast, after 6 h of ischemia, rSO2 did not increase after reperfusion, and all animals died within 2 days. The histological scores increased after 1 h of reperfusion, with longer clamping periods.

CONCLUSION

A finger-mounted tissue oximeter could evaluate intestinal ischemia and the viability, which is thus considered to be a promising result for future clinical application.

The role of the intestinal ultrasound in Crohn's disease diagnosis and monitoring

Crohn's disease is characterized by persistent or recurrent chronic inflammation that may affect any segment of the gastrointestinal tract. It has an oscillating evolution, with periods of activity alternating with periods of remission. Crohn's disease has a significant impact on the economic status due to its increasing prevalence, often affecting young people. Suitable management for these patients involves frequent evaluations. Even though colonoscopy is the gold standard for the assessment of severity and mucosal healing, it is an invasive maneuver, not easily accepted by patients, and it does not have good repeatability. Intestinal ultrasound has the advantage of being non-irradiating, non-invasive, well-tolerated, cheap, and easy to repeat. Ultrasound parameters such as bowel wall thickness, intestinal wall architecture, intramural vascularisation, proliferation of mesenteric fatty conjunctive tissue, and intraperitoneal fluid can provide good information regarding the severity of the disease, the differentiation between remission and relapse, and its complications. Some of the latest studies show good correlations between ultrasound parameters and inflammation markers (C-reactive protein, fecal calprotectin) and clinical severity scores of Crohn's disease. Consequently, the importance of intestinal ultrasound has increased lately, and recent studies support its use to evaluate the severity of inflammation, differentiate between active disease and relapse, monitor therapy response and guide treatment, evaluate prognosis, and diagnose complications.

Small bowel radiology

PURPOSE OF REVIEW

Recent advances in computed tomography (CT), ultrasound (US), magnetic resonance imaging (MRI), and nuclear radiology have improved the diagnosis and characterization of small bowel pathology. Our purpose is to highlight the current status and recent advances in multimodality noninvasive imaging of the small bowel.

RECENT FINDINGS

CT and MR enterography are established techniques for small bowel evaluation. Dual-energy CT is a novel technique that has shown promise for the mesenteric ischemia and small bowel bleeding. Advanced US techniques and MRI sequences are being investigated to improve assessment of bowel inflammation, treatment response assessment, motility, and mural fibrosis. Novel radiotracers and scanner technologies have made molecular imaging the new reference standard for small bowel neuroendocrine tumors. Computational image analysis and artificial intelligence (AI) have the potential to augment physician expertise, reduce errors and variability in assessment of the small bowel on imaging.

SUMMARY

Advances in translational imaging research coupled with progress in imaging technology have led to a wider adoption of cross-sectional imaging for the evaluation and management of small bowel entities. Ongoing developments in image acquisition and postprocessing techniques, molecular imaging and AI have the strongest potential to transform the care and outcomes of patients with small bowel diseases.

Bowel wall thickening and hyperemia assessed by high-frequency ultrasound indicate histological inflammation in Crohn's ileitis

PURPOSE

We evaluated ileal bowel wall thickness and semiquantitative vascularization by ultrasound in correlation with the presence or absence of histopathological inflammation in patients with Crohn's disease (CD).

METHODS

We conducted a retrospective analysis of 221 ultrasound examinations of the terminal ileum or neoterminal ileum in CD patients with biopsies of the ileum during colonoscopies within 8 weeks of the ultrasound. Ultrasound data were obtained from an inflammatory bowel disease ultrasound register from 2011 to 2017. Bowel wall ultrasound was performed by a high-frequency, linear transducer (7-12 MHz). Presence of bowel wall thickening (> 3 mm), vascularization by the Limberg score, and presence of ileal histopathological inflammation were analyzed.

RESULTS

In 221 bowel wall ultrasound examinations of CD patients (128 female, 93 male, mean age 37.5 years), a thickened bowel wall was found in 140 (63.3%) and hypervascularization (corresponding to a Limberg score ≥ 2) in 96 (43.4%) cases. In 187 (84.6%) cases, ileal inflammation was confirmed by histopathology and in 34 (15.4%) cases no inflammation was shown. Bowel wall thickening showed a sensitivity of 70.1%, a negative predictive value (NPV) of 30.9%, a specificity of 73.5% and a positive predictive value (PPV) of 93.6% for the detection of histopathological ileal inflammation. Hypervasularization had a low sensitivity (49.7%) and NPV (24.8%), but high specificity (91.2%) and PPV (96.9%).

CONCLUSION

In this CD subcohort of an ultrasound register, pathologic ultrasound findings were quite common. Bowel wall thickening (> 3 mm) and hypervascularization are good predictors of histopathological inflammation within the terminal ileum or neoterminal ileum. Normal ultrasound findings without bowel wall thickening and without hypervascularization do not rule out histopathological inflammation.

Non-invasive Ultrasonographic Score for Assessment of the Severity of Inflammatory Bowel Disease

Intestinal ultrasound and shear wave elastography have gained increasing interest because of their promising results in the assessment of inflammatory bowel disease. The aim of this study was to find an ultrasonographic score to replace invasive endoscopic procedures for the management of these patients. The score includes ultrasound parameters that correlate well with clinical severity scales and inflammatory markers: bowel wall thickness, the Limberg score, disease extension and acoustic radiation force impulse measurements. The score proved to be well correlated with the Harvey Bradshaw Index, the Mayo score, C-reactive protein and fecal calprotectin. For Crohn's disease, a cutoff value of 8 points could identify active disease with 81.81% sensitivity and 83% specificity, while for ulcerative colitis, a cutoff value of 7 points could discriminate between remission and relapse with 86.85% sensitivity and 94% specificity. In conclusion, our ultrasonographic score can differentiate relapse from remission in inflammatory bowel disease.

Correlation between endoscopy and intestinal ultrasound for the evaluation of postoperative recurrence of Crohn's disease

OBJECTIVE

Intestinal ultrasound is considered to be a valid alternative for the evaluation of post-operative recurrence (POR) of Crohn's disease. The aim of this study is to assess the correlation between ultrasound and endoscopic findings.

METHODS

Patients with Crohn's disease were retrospectively recruited who had undergone ileocecal resection, and for whom a colonoscopy and intestinal ultrasound had been performed for the detection of POR. Recurrence was assessed using the Rutgeerts score (RS). The ultrasound findings analysed were bowel wall thickness (BWT), parietal hyperaemia using power Doppler, loss of layer pattern and mesenteric fat hypertrophy.

RESULTS

A total of 31 patients were included, of which 15 (48.4%) had no POR (RS<2b) and 16 (51.6%) had POR (RS≥2b). A statistically significant association was identified between BWT and the presence of endoscopic recurrence (a mean of 2.75mm vs. 5.68mm, P>0.001). There was also a statistically significant difference in hyperaemia between the 2groups (P=0.03). For wall thickness, an area under the ROC curve (AUC) of 92.9% was obtained, and with a cut-off point of 3.4mm, a sensitivity of 100% and specificity of 86.6%. When comparing with the most frequent biomarkers (fecal calprotectin and serum CRP), a higher AUC was obtained for wall thickness (72.3% and 72.3% vs. 92.9%).

CONCLUSIONS

In our experience, ultrasound has high diagnostic efficacy in the detection of POR and can be considered a valid non-invasive alternative to endoscopy.

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.

The establishment of a regression model from four modes of ultrasound to predict the activity of Crohn's disease

To establish a multi-parametric regression model from four modes of ultrasound to predict the activity of Crohn's disease (CD) noninvasively. Score of 150 of the Crohn’s Disease Activity Index (CDAI) was taken as the cut-off value to divide the involved bowel segments of 51 patients into the active and inactive group. Eleven parameters from four modes of ultrasound (B-mode ultrasonography, color Doppler flow imaging, contrast-enhanced ultrasonography and shear wave elastography) were compared between the two groups to investigate the relationship between multimodal ultrasonic features and CD activity. P < 0.05 was considered statistically significant. Parameters with AUC larger than 0.5 was selected to establish the prediction model of CDAI. Totally seven ultrasound parameters (bowel wall thickness, mesenteric fat thickness, peristalsis, texture of enhancement, Limberg grade, bowel wall perforation and bowel wall stratification) were significantly different between active and inactive group. A regression model was established based on the seven parameters as followed: CDAI = 211.325 + 3.186BWT − 53.003BWS + 6.280BWP + 0.392MFT + 22.239PS + 79.012LG + 72.793TE. (R² = 0.72, P = 0.037). The multimodal ultrasound parametric regression model was designed to predict CDAI score invasively. The model has the potential to provide an alternative method for quantifying the CD activity.

Diagnosis of Inflammatory Bowel Disease by Abdominal ultrasound and Color Doppler Techniques

Background &Aims: The utility of ultrasound and color Doppler in diagnosis and assessment of the activity of inflammatory bowel diseases (IBD) is not studied enough. So, the aim of the current study was to evaluate the value of conventional abdominal ultrasound and color Doppler in the diagnosis of IBD and assessing disease activity.

METHODS

The study was conducted in National Hepatology and Tropical Medicine Research institute (NHTMRI) in the period between July, 2018 and January, 2019; where 150 patients suffering from diarrhea, dysentery, tenesmus or bleeding per rectum were evaluated by colonoscopy, high resolution ultrasonography and color Doppler scanning.

RESULTS

The present study was conducted on 150 patients, where 84 (56%) had Ulcerative colitis (UC) disease, 16 (10.7%) were Crohn's disease (CD) and 50 (33.3%) had normal colonosopic findings with their mean age was (37.2±9.059). The superior mesenteric artery (SMA) peak systolic velocity (PSV) and end diastolic velocity (EDV) was significantly higher in both UC and CD than the control group; however, pulsatility index (PI) was significantly higher in the control group than both UC and CD however there was no significant difference between UC and CD. The inferior mesenteric artery (IMA) PSV and EDV was significantly higher in both UC and CD than the control group.

CONCLUSIONS

Doppler sonographic findings of SMA and IMA correlate with the incidence of IBD and their site of affection and their activity.

Evaluation of Crohn's Disease Activity: Development of an Ultrasound Score in a Multicenter Study

OBJECTIVE

Our goal in this multicentric prospective study was 2-fold: first, to test the diagnostic accuracy of ultrasound, color Doppler imaging (CDI), and contrast-enhanced ultrasound (CEUS) in identifying disease activity in patients with Crohn's disease (CD) compared with endoscopy as the reference standard; and, second, to construct a sonographic score that allows disease activity to be detected.

MATERIALS AND METHODS

Seventy-two patients with CD from 3 hospitals underwent within a 30-day period both colonoscopy and ultrasound (US), including mural thickness, CDI, and CEUS, prospectively as part of clinical care. A multivariate analysis was carried out to assess the influence of each of the ultrasound variables in predicting endoscopic activity. We then developed a predictive ultrasound score for disease activity, and a receiver operating characteristic (ROC) curve was constructed to determine the area under the ROC curve (AUC) and the best cut-off score value to discriminate between active and inactive disease.

RESULTS

Sonographic findings that were independent predictors of the presence of active disease at endoscopy were wall thickness, color grade, and contrast parameters. A score based on those variables showed high accuracy in predicting active disease, with an area under the ROC curve of 0.972. A simpler index, without contrast parameters, also showed high accuracy in detecting disease activity (AUC, 0.923).

CONCLUSION

A score based on wall thickness, color Doppler grade, and contrast parameters showed high accuracy in predicting active disease. A score without including the use of contrast agent had practically similar results and is easier to use in monitoring response to treatment.

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.

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.

Comparative study between bowel ultrasound and magnetic resonance enterography among Egyptian inflammatory bowel disease patients

BACKGROUND

Bowel ultrasound and magnetic resonance enterography (MRE) are decisive medical imaging modalities for diagnosing and locating bowel lesions with its extramural extent and complications. They assess the degree of activity, help clinicians to identify patients in need of surgery, and can be used for patient follow-up.

AIM

To compare the role of MRE and bowel ultrasound in diagnosis and follow-up of inflammatory bowel disease (IBD) patients in Egypt.

METHODS

The study was conducted on 40 patients with IBD. All patients were subjected to clinical assessment, laboratory investigations, bowel ultrasound, MRE, and colonoscopy up to the terminal ileum with biopsies for histopathological examination.

RESULTS

This study was conducted on 14 patients (35%) with ulcerative colitis and 26 patients (65%) with Crohn's disease; 34 (85%) of these patients had active disease. Bowel ultrasound detected different bowel lesions with the following accuracies: ileum (85%), large bowel (70%), fistula (95%), stricture and proximal dilatation (95%) and abscesses (100%). Also, it showed that statistically significance of bowel ultrasound in differentiation between remission and activity of IBD in comparison to MRE and colonoscopy.

CONCLUSION

In comparison to MRE, bowel ultrasound is a useful, non-invasive, and feasible bedside imaging tool for the detection of inflammation, detection of complications, and follow-up of IBD patients when performed by the attending physician.

Magnetic resonance enterography compared with ultrasonography in newly diagnosed and relapsing Crohn's disease patients: the METRIC diagnostic accuracy study

BACKGROUND

Magnetic resonance enterography and enteric ultrasonography are used to image Crohn's disease patients. Their diagnostic accuracy for presence, extent and activity of enteric Crohn's disease was compared.

OBJECTIVE

To compare diagnostic accuracy, observer variability, acceptability, diagnostic impact and cost-effectiveness of magnetic resonance enterography and ultrasonography in newly diagnosed or relapsing Crohn's disease.

DESIGN

Prospective multicentre cohort study.

SETTING

Eight NHS hospitals.

PARTICIPANTS

Consecutive participants aged ≥ 16 years, newly diagnosed with Crohn's disease or with established Crohn's disease and suspected relapse.

INTERVENTIONS

Magnetic resonance enterography and ultrasonography.

MAIN OUTCOME MEASURES

The primary outcome was per-participant sensitivity difference between magnetic resonance enterography and ultrasonography for small bowel Crohn's disease extent. Secondary outcomes included sensitivity and specificity for small bowel Crohn's disease and colonic Crohn's disease extent, and sensitivity and specificity for small bowel Crohn's disease and colonic Crohn's disease presence; identification of active disease; interobserver variation; participant acceptability; diagnostic impact; and cost-effectiveness.

RESULTS

Out of the 518 participants assessed, 335 entered the trial, with 51 excluded, giving a final cohort of 284 (133 and 151 in new diagnosis and suspected relapse cohorts, respectively). Across the whole cohort, for small bowel Crohn's disease extent, magnetic resonance enterography sensitivity [80%, 95% confidence interval (CI) 72% to 86%] was significantly greater than ultrasonography sensitivity (70%, 95% CI 62% to 78%), with a 10% difference (95% CI 1% to 18%; p = 0.027). For small bowel Crohn's disease extent, magnetic resonance enterography specificity (95%, 95% CI 85% to 98%) was significantly greater than ultrasonography specificity (81%, 95% CI 64% to 91%), with a 14% difference (95% CI 1% to 27%). For small bowel Crohn's disease presence, magnetic resonance enterography sensitivity (97%, 95% CI 91% to 99%) was significantly greater than ultrasonography sensitivity (92%, 95% CI 84% to 96%), with a 5% difference (95% CI 1% to 9%). For small bowel Crohn's disease presence, magnetic resonance enterography specificity was 96% (95% CI 86% to 99%) and ultrasonography specificity was 84% (95% CI 65% to 94%), with a 12% difference (95% CI 0% to 25%). Test sensitivities for small bowel Crohn's disease presence and extent were similar in the two cohorts. For colonic Crohn's disease presence in newly diagnosed participants, ultrasonography sensitivity (67%, 95% CI 49% to 81%) was significantly greater than magnetic resonance enterography sensitivity (47%, 95% CI 31% to 64%), with a 20% difference (95% CI 1% to 39%). For active small bowel Crohn's disease, magnetic resonance enterography sensitivity (96%, 95% CI 92% to 99%) was significantly greater than ultrasonography sensitivity (90%, 95% CI 82% to 95%), with a 6% difference (95% CI 2% to 11%). There was some disagreement between readers for both tests. A total of 88% of participants rated magnetic resonance enterography as very or fairly acceptable, which is significantly lower than the percentage (99%) of participants who did so for ultrasonography. Therapeutic decisions based on magnetic resonance enterography alone and ultrasonography alone agreed with the final decision in 122 out of 158 (77%) cases and 124 out of 158 (78%) cases, respectively. There were no differences in costs or quality-adjusted life-years between tests.

LIMITATIONS

Magnetic resonance enterography and ultrasonography scans were interpreted by practitioners blinded to clinical data (but not participant cohort), which does not reflect use in clinical practice.

CONCLUSIONS

Magnetic resonance enterography has higher accuracy for detecting the presence, extent and activity of small bowel Crohn's disease than ultrasonography does. Both tests have variable interobserver agreement and are broadly acceptable to participants, although ultrasonography produces less participant burden. Diagnostic impact and cost-effectiveness are similar. Recommendations for future work include investigation of the comparative utility of magnetic resonance enterography and ultrasonography for treatment response assessment and investigation of non-specific abdominal symptoms to confirm or refute Crohn's disease.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN03982913.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 42. See the NIHR Journals Library website for further project information.

Terminal Ileum Thickness During Maintenance Therapy Is a Predictive Marker of the Outcome of Infliximab Therapy in Crohn Disease

BACKGROUND

Mucosal healing has been associated with long-term response to therapy for Crohn disease (CD). However, little is known about the significance of terminal ileum (TI) transmural thickness in predicting clinical outcomes.

METHODS

In this retrospective observational cohort study, we examined the association of an index ultrasonographic assessment of TI thickness during the maintenance phase and the subsequent clinical outcome of CD in a cohort of patients treated with infliximab (IFX). Treatment failure was defined as treatment discontinuation because of lack of efficacy, a need for dose escalation, or surgery. Clinical response was defined as treatment continuation in the absence of any of the aforementioned failure criteria.

RESULTS

Sixty patients with CD receiving IFX therapy were included in the study. The patients were followed for a median of 16 months (5-24 months) after an index intestinal ultrasound. Thirty-eight patients (63.3%) maintained response to the therapy and 22 patients (36.6%) failed the treatment, with a mean follow up of 10.5 months (6.5-17 months) vs 9.25 months (1-10.25 months), respectively. On univariate analysis, the only variables differing between treatment response and failure were a TI thickness of 2.8 vs 5 mm (P < 0.0001) and an IFX trough level of 6.6 vs 3.9 µg/mL (P = 0.008).On multivariable analysis, only a small bowel thickness of ≥4 mm was associated with the risk of treatment failure (odds ratio, 2.9; 95% CI, 1.49-5.55; P = 0.002).

CONCLUSIONS

Our findings suggest that transmural thickness of ≥4 mm can predict subsequent treatment failure in patients with CD treated using IFX, indicating transmural thickness <4 mm as a potential novel valuable therapeutic target.

Doppler Activity and Ultrasonographic Detection of Intra-Abdominal Fistulas Are Predictors of Surgery in Crohn's Disease

Bakground and Aim: Predictors of the need for surgery in sticturing Crohn's disease (SCD) are lacking. Bowel ultrasound (US) is a harmless, noninvasive, and inexpensive diagnostic procedure that has proven to be a valuable tool in the management of Crohn's disease (CD). Our aim was to identify ultrasonographic findings in SCD that may associate with a higher risk of surgery, allowing us to make early choices regarding treatment election in this specific group of patients.

MATERIALS AND METHODS

This was a retrospective, case-control study. Twenty-four patients diagnosed with SCD between 2013 and 2017 with a past history of stricture-related surgery were included and then matched with 46 non-operated controls. Prior US from patients in both groups were analyzed. US features considered for analysis were as follows: bowel wall thickness, degree of parietal vascularization (measured by Doppler activity), prestenotic dilation, involvement of mesenteric fat, and newly detected concomitant fistulas or abscess.

RESULTS

Doppler activity (p < 0.001), enteroenteric fistulas (p = 0.04), enteromesenteric fistulas (p = 0.003), and associated abscess (p = 0.004) were significantly associated with the need for surgery in the short-term period. Multivariate analysis showed strong association of these features with the risk of surgery but failed to reach statistical significance.

CONCLUSION

US features may potentially be used as point-of-care tools to aid clinicians in the assessment of the surgical risk in patients with SCD.

Accuracy of point-of-care intestinal ultrasound for Crohn's disease

Background

Point-of-care ultrasound (POCUS), performed by a gastroenterologist, provides safe and convenient imaging allowing for immediate clinical decision in Crohn's disease. The minimum training required to gain competency, its accuracy and clinical utility requires evaluation.

Methods

In this pilot study, Crohn's disease activity and extent were assessed using POCUS (performed by a single gastroenterologist following the completion of 200 supervised scans), magnetic resonance enterography (MRE) and ileo-colonoscopy. The presence of complications was assessed by POCUS and MRE. Accuracy of POCUS was analysed with respect to MRE and ileo-colonoscopy. Agreement between modalities was assessed using kappa coefficient.

Results

Forty-two patients had a POCUS paired with MRE. Thirty-eight patients had a POCUS paired with ileo-colonoscopy. When compared to MRE, POCUS was accurate in the assessment of disease activity (sensitivity 87.5%, specificity 61.1%, ROC 0.74), extent (sensitivity 77.8%, specificity 83.3%, ROC 0.81) and complications (sensitivity 85.7%, specificity 94.3%, ROC 0.90). Agreement between POCUS and MRE was moderate (kappa estimates 0.50, P < 0.001, 0.61, P < 0.001 and 0.76, P < 0.001) for disease activity, extent and complications, respectively. When compared to ileo-colonoscopy, POCUS was accurate in the assessment of disease activity (sensitivity 72%, specificity 86%, ROC 0.79) and extent (sensitivity 85.7%, specificity 86%, ROC 0.86). For POCUS and ileo-colonoscopy, kappa estimates were 0.55, P < 0.001 for disease activity and 0.62, P < 0.001 for disease extent.

Conclusion

POCUS performed by a gastroenterologist after completion of limited training is accurate for assessing Crohn's disease activity, extent and the presence of complications.

CROHN'S DISEASE. CLINICAL RECOMMENDATIONS (PRELIMINARY VERSION)

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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.

ACR Appropriateness Criteria® Crohn Disease

Three common clinical scenarios involving use of imaging in Crohn disease are covered. These include the initial evaluation of Crohn disease when the diagnosis has not been previously established, the evaluation for anticipated exacerbation of known disease, and the evaluation of disease activity during therapy monitoring. The appropriateness of a given imaging modality for each scenario is rated as one of three categories (usually appropriate, may be appropriate, usually not appropriate) to help guide evaluation. Pediatric presentation of Crohn disease and the appropriateness of imaging are not covered in this document. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.