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

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.

Nongynecologic Causes of Pelvic Pain: Ultrasound First

Ultrasonography (US) is often the first-line imaging study used to evaluate women who present with acute or chronic pelvic pain. Detection of nongynecologic causes of pelvic pain is critical, because delay in diagnosis can cause significant morbidity and mortality. Evaluation of these entities requires a variety of transducers to achieve optimal imaging depth and changes in patient positioning. Specific imaging techniques (such as graded compression) may be required if bowel pathology is suspected. Contrast-enhanced ultrasonography is increasingly used to improve detection of certain entities. The US appearance of common gastrointestinal and urinary tract-related causes of pelvic pain is reviewed.

Impact of intestinal ultrasound on the management of patients with inflammatory bowel disease: how to apply scientific evidence to clinical practice

Technological improvements and growing sonographers' expertise boost the role of intestinal ultrasound (IUS) in assessing patients with inflammatory bowel diseases (IBD). Non-invasiveness, low cost and good reproducibility make IUS attractive. Leveraging on the Authors' long-term field experience, this review focuses on the IUS role in IBD patients' clinical management. For detecting IBD, particularly Crohn's disease, the IUS parameters - above all the evidence of a thickened bowel wall (BWT) - show very good diagnostic accuracy similar to that of MRI or CT scan. The standard IUS parameters are not accurate enough to detect inflammatory activity, but intravenous contrast-enhanced US (CEUS) is highly accurate in ruling active inflammation out. However, its routinely use remains limited in clinical practice and its parameters need standardization. IUS is accurate in detecting IBD main complications: in particular, fistulae and abscesses. As to stenosis the recent introduction of IUS-based elastographic techniques allows to differentiate prevalently inflammatory from highly fibrotic strictures. IUS proves valid also for monitoring IBD patients. In particular, the evidence of transmural healing, defined as BWT normalization, has got an important prognostic meaning, as associated with better long-term clinical outcomes. Post-surgery CD recurrence can be suggested by early IUS assessment.

Diagnostic Accuracy of Transabdominal Ultrasound in Detecting Intestinal Inflammation in Paediatric IBD Patients-a Systematic Review

BACKGROUND AND AIMS

Currently used non-invasive tools for monitoring children with inflammatory bowel disease [IBD], such as faecal calprotectin, do not accurately reflect the degree of intestinal inflammation and do not provide information on disease location. Ultrasound [US] might be of added value. This systematic review aimed to assess the diagnostic test accuracy of transabdominal US in detecting intestinal inflammation in children with IBD in both diagnostic and follow-up settings.

METHODS

We systematically searched PubMed, Embase [Ovid], Cochrane Library, and CINAHL [EBSCO] databases for studies assessing diagnostic accuracy of transabdominal US for detection of intestinal inflammation in patients diagnosed or suspected of IBD, aged 0-18 years, with ileo-colonoscopy and/or magnetic resonance enterography [MRE] as reference standards. Studies using US contrast were excluded. Risk of bias was assessed with QUADAS-2.

RESULTS

The search yielded 276 records of which 14 were included. No meta-analysis was performed, because of heterogeneity in study design and methodological quality. Only four studies gave a clear description of their definition for an abnormal US result. The sensitivity and specificity of US ranged from 39-93% and 90-100% for diagnosing de novo IBD, and 48-93% and 83-93% for detecting active disease during follow-up, respectively.

CONCLUSIONS

The diagnostic accuracy of US in detecting intestinal inflammation as seen on MRE and/or ileo-colonoscopy in paediatric IBD patients remains inconclusive, and there is currently no consensus on defining an US result as abnormal. Prospective studies with adequate sample size and methodology are needed before US can be used in the diagnostics and monitoring of paediatric IBD.

Correlation between the macroscopic severity of Crohn's disease in resected intestine and bowel wall thickness evaluated by water-immersion ultrasonography

Objectives: Transabdominal ultrasonography is a common and accurate tool for managing Crohn's disease (CD); however, the significance of the resulting data is poorly understood. This study was performed to determine the association between bowel wall thickness evaluated by water-immersion ultrasonography and macroscopic severity, namely, refractory inflammation and subsequent fibrosis in CD surgical specimens.Materials and methods: We retrospectively evaluated 100 segments of colon and small intestine from 27 patients with CD. The resected specimens were placed in saline postoperatively, and bowel wall thickness was measured by water-immersion ultrasonography and compared with macroscopic findings. Correlations between bowel wall thickness and macroscopic findings were assessed using analysis of variance and receiver operating characteristic curves.Results: According to the progression of macroscopic severity, the mean bowel wall thickness was increased as follows: macroscopically intact: 4.1 mm, longitudinal ulcer scars: 5.4 mm, longitudinal open ulcers: 6.0 mm, large ulcers: 6.4 mm, cobblestone-like lesions: 7.1 mm, and fibrotic strictures: 7.4 mm. For all lesions except longitudinal ulcer scars, the bowel wall thickness was significantly thicker than that of macroscopically-intact areas (p < .001). According to receiver operating characteristic curves, bowel wall thickness >4.5 mm was associated with CD lesions, and thickness >5.5 mm was associated with more severe lesions.Conclusions: The bowel wall thickness of CD lesions was evaluated by water-immersion ultrasonography correlated with macroscopic disease severity.

Lower adalimumab trough levels are associated with higher bowel wall thickness in Crohn's disease

BACKGROUND

In Crohn's disease, higher adalimumab trough levels and negative anti-adalimumab-antibodies associate with better clinical and endoscopic outcomes. Intestinal ultrasound has become a relevant non-invasive method to monitor treatment. However, data on the association between adalimumab levels and bowel wall thickness measured with ultrasound is limited.

OBJECTIVE

The purpose of this study was to examine the possible association between the sonographic transmural-thickness and adalimumab trough levels.

METHODS

This prospective observational cohort study was conducted at Sheba Medical Center in 2014-2018. Crohn's disease patients on adalimumab maintenance therapy with intestinal ultrasound performed within <30 days of trough level measurement were included. Associations between terminal ileum and colonic thickness, adalimumab levels and therapy retention were assessed.

RESULTS

Fifty events of ultrasound with concomitant adalimumab trough level measurements in 44 Crohn's disease patients were included. Patients with trough level <3 μg/ml had significantly higher bowel wall thickness, both for terminal ileum (p = 0.04) and colon (p = 0.02). Thirty-two patients continued adalimumab therapy over one year. The adalimumab retention rate was higher among those with terminal ileum thickness <4 mm (p = 0.03).

CONCLUSION

Lower adalimumab trough levels were associated with higher bowel wall thickness indicating poorer therapy outcome. Transmural thickness measurement with ultrasound may be a useful target for guiding biologic therapy in Crohn's disease.

Clinical Impact of Sonographic Transmural Healing After Anti-TNF Antibody Treatment in Patients with Crohn's Disease

AIM

To assess the clinical benefits of transmural healing (TH) shown on intestinal ultrasound (IUS) after treatment with tumor necrosis factor-alpha antibodies (anti-TNF) in patients with Crohn's disease.

MATERIALS AND METHODS

This prospective study included consecutively 36 patients who underwent IUS in the week prior to start anti-TNF treatment, at 12 weeks, and 1 year after starting treatment. The clinical response to treatment was assessed using the Crohn's disease activity index and C-reactive protein (CRP) values. TH was defined as the normalization of bowel wall thickness on IUS. Treated patients were considered to have a good outcome if none of the following situations presented: need to reintroduce corticosteroids or intensify maintenance therapy and/or need for surgery.

RESULTS

After the induction regimen, 29 patients (80.6%) achieved clinical remission, and serum CRP values returned to normal in 20 patients (55.6%). In the IUS at 12 weeks, treatment induced a statistically significant reduction in the wall thickness (p < 0.001) and color Doppler grade (p < 0.001), as well as resolution of complications in 66.7% of patients (p < 0.03). IUS after 1 year of biological therapy showed TH in 14/33 patients (42.4%). During the follow-up (median 48.5 months), 23 of the 33 (69.7%) patients in remission or response after induction therapy presented a good outcome. Sonographic TH was significantly related with better outcomes, with only 1/14 patients having a poor outcome compared to 9/19 without TH (OR 11.7, 95% CI 1.2-108.2 p = 0.01, Chi-squared test).

CONCLUSION

Patients who achieve TH on IUS with biological treatment have better clinical outcomes.

The Simple Pediatric Activity Ultrasound Score (SPAUSS) for the Accurate Detection of Pediatric Inflammatory Bowel Disease

OBJECTIVE

The aim of the study was to identify the most significant ultrasound (US) parameters that predict inflammatory activity and develop a simple US activity score.

METHODS

Patients were identified through retrospective evaluation of an established database of children with inflammatory bowel disease (IBD). Patients with endoscopy and US within 60 days were included (N = 75). US parameters evaluated included: bowel wall thickness (BWT), mesenteric inflammatory fat, lymphadenopathy, and hyperemia. The weighted kappa statistic was calculated to assess agreement between sonographic and endoscopically identified disease location. Using a proportional odds model and ordinal logistic regression, statistically significant (P < 0.05) parameters were used to generate a score. Variables were weighted to classify individuals into severity classes. Receiver operating characteristic curves were plotted to demonstrate the score's discriminative and predictive capacity.

RESULTS

There was substantial agreement between US and endoscopy for all disease locations (weighted kappa = 0.85) and substantial agreement for ileocolonic disease (weighted kappa = 0.96). Two sonographic parameters were identified as contributing significantly to disease activity: BWT and mesenteric inflammatory fat (P < 0.05). A predictive score was developed incorporating BWT, hyperemia and inflammatory fat, and receiver operating characteristic curve curves demonstrated good predictive capacity to distinguish between the absence of disease (normal) and active disease with an area under the curve of 82.1%.

CONCLUSIONS

The most important sonographic parameters for predicting disease activity were BWT and mesenteric inflammatory fat. When combined with hyperemia into a simple score, there was accurate detection of inflammatory activity in children with inflammatory bowel disease. This score may facilitate noninvasive, bedside detection of inflammation, and standardize the use of US in children.

Differentiation of Crohn's disease and ulcerative colitis using intestinal wall thickness of the colon: A Diagnostic accuracy study of endoscopic ultrasonography

Background: The differentiation between Ulcerative Colitis (UC) and Crohn's Disease (CD) is an important issue for choosing the appropriate treatment. Endoscopic Ultrasonography (EUS) has been used to distinguish different layers of the gastrointestinal wall. We performed this study to evaluate the accuracy of EUS in differentiating colonic UC from CD compared to standard tests (colonoscopy, pathology, imaging, and clinical presentation). Methods: This is a prospective, single-blinded diagnostic accuracy study, on 70 patients (30 UC, 30 CD, and 10 healthy controls). After obtaining informed consent, patients underwent a complete workup and were referred to an endosonographist who was blind to the diagnosis. The thickness of mucosa, submucosa and the total wall (TWT) of mid-sigmoid colon were measured by Pentax radial echoendoscope EPKI-7000 with Avius Hitachi ultrasound system (Japan). Statistical analyses were performed using the SPSS statistical software (v23). Statistical significance was considered if P-values were less than 0.05. Results: Our study revealed a sensitivity of 100% (90.7-100%) and specificity of 90.9% (70.8-98.8%) for EUS to differentiate UC and CD compared to standard diagnostic tests. Mean mucosal thickness in patients with UC was significantly greater than patients with CD, while, the mean sub-mucosal thickness was significantly greater in patients with CD (p<0.001). The sensitivity and specificity of mean mucosal thickness for differentiating UC from CD and controls were 92.3% and 88.6% with a cut-off point of 1.1 mm (p<0.001). Moreover, sensitivity and specificity of mean submucosal thickness for differentiating CD from UC and controls were 100% and 86.1% with a cut-off point of 1.08 mm (p<0.001). Conclusion: EUS can be used as an efficient modality with acceptable accuracy to differentiate Crohn's disease and Ulcerative Colitis and to determine disease activity.

Noninvasive testing in the management of children with suspected inflammatory bowel disease

Objective: To assess the accuracy of noninvasive parameters, fecal calprotectin (FC), increased bowel wall thickening (BWT) at intestinal ultrasound (IUS) and blood inflammatory indexes (BII), alone or in combination, as diagnostic tools for inflammatory bowel disease (IBD) in pediatric patients. Methods: Retrospective data were collected on consecutive children (age 2-18 years) referred to our pediatric gastroenterology clinic, for recurrent abdominal pain and/or altered bowel habit from 2007 to 2013. Subjects who had diagnostic workup: laboratory tests (FC, BII, white blood cell (WBC), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR)) and IUS as initial assessment were eligible. Subjects with known gastrointestinal (GI) diseases, or signs or symptoms highly suggestive for organic diseases necessitating prompt endoscopy (e.g., perianal disease or rectal bleeding), or who had recently performed endoscopy were excluded. The accuracy of noninvasive tests for detecting IBD was assessed using endoscopic and/or radiological investigations, performed in subsequent clinical follow up, as reference gold standard. Results: Seventy-seven patients (mean age 11.3, 44 males) were included, 23 (29.9%) with a final diagnosis of IBD. As single tests, FC gave the highest sensitivity (96%) but lower specificity (72%) and IUS highest specificity (96%) with lower sensitivity (70%). The combination of FC + IUS showed excellent accuracy for detecting children with IBD with positive predictive value: 100%; negative predictive value: 88.5%. The probability of IBD in children with normal FC, BII and IUS was 0.09%. Conclusions: FC and increased BWT at IUS are accurate to guide reassurance or proceeding with further invasive procedures for detecting IBD in children with mild GI symptoms.

Intra-Cavitary Contrast-Enhanced Ultrasound: A Novel Radiation-Free Method for Detecting Abscess-Associated Penetrating Disease in Crohn's Disease

BACKGROUND AND AIM

Penetrating disease is a common condition complicating Crohn's disease [CD]. Establishing the presence of a fistula and the anatomical definition of the fistulous tracts are essential for deciding on appropriate treatment strategies. We aimed to assess the diagnostic accuracy of intra-cavitary contrast-enhanced ultrasound [IC-CEUS] for the detection of a fistulous tract associated with abscesses in CD patients.

METHODS

In this prospective cohort study, consecutive CD patients suspected of having an intra-abdominal abscess, who were referred for US-guided aspiration were recruited. IC-CEUS was performed by injecting diluted contrast agent [SonoVue] into the abscess cavity immediately following the ultrasound-guided needle abscess aspiration and drainage. The diagnostic accuracy of IC-CEUS in demonstrating the presence of fistulous tracts was compared with that of computed tomography enterography/magnetic resonance enterography [CTE/MRE], using surgical and gross pathological findings as the reference standard.

RESULTS

Thirty-one patients who underwent IC-CEUS and subsequent surgery were included in the final analysis. IC-CEUS demonstrated fistulous/sinus tracts in 26 of 31 participants with a sensitivity and specificity of 86.7 % (95% confidence interval [CI], 68.4-95.6%) and 100% [95% CI, 5.5-100.0%], respectively. Moreover, IC-CEUS correctly demonstrated fistulous/sinus tracts in 13 participants without delineation of fistulous/sinus tracts on CTE/MRE. Combining IC-CEUS and CTE/MRE, the fistula/sinus tract was clearly demonstrated in 29 patients [93.5%, 29/31]. The mean duration of the IC-CEUS procedure was 8.6 min [range 5.0-12.0]. No severe adverse events occurred during the IC-CEUS procedure.

CONCLUSION

In this pilot study, IC-CEUS accurately delineated the anatomical definition of fistulous/sinus tracts associated with intra-abdominal abscesses in CD patients. As a radiation-free and safe technique, IC-CEUS may be used as an alternative/adjunctive method to CTE/MRE for detecting penetrating disease in patients with CD.

One-year clinical outcomes with biologics in Crohn's disease: transmural healing compared with mucosal or no healing

BACKGROUND

While mucosal healing has been proved to predict relevant clinical outcomes in Crohn's disease (CD), little is known about the long-term significance of transmural healing.

AIMS

To prospectively assess the 1-year clinical outcomes in CD patients achieving transmural healing following treatment with biologics, and to compare them with those in patients reaching only mucosal healing or no healing.

METHODS

Observational longitudinal study, evaluating 1-year outcomes in terms of steroid-free clinical remission, rate of hospitalisation and need for surgery in a group of CD patients treated with anti-tumour necrosis factor (TNF) alpha for 2 years. Bowel sonography was used in all patients to determine transmural healing.

RESULTS

Of 218 patients who completed a 2-year treatment course with anti-TNF alpha, 68 (31.2%) presented transmural (plus mucosal) healing (bowel wall thickness ≤3 mm at bowel sonography), 60 (27.5%) mucosal healing only, and 90 (41.3%) did not achieve any intestinal healing. Transmural healing was associated with a higher rate of steroid-free clinical remission (95.6%), lower rates of hospitalisation (8.8%) and need for surgery (0%) at 1 year compared to mucosal (75%, 28.3% and 10%, respectively) and no healing (41%, 66.6% and 35.5%, respectively) (P < 0.001). Furthermore, transmural healing was associated with longer intervals until clinical relapse (HR, hazard ratio 0.87, P = 0.01), hospitalisation (HR 0.88, P = 0.002) and surgery (HR 0.94, P = 0.008) than mucosal healing. Also among patients discontinuing treatment with biologics, transmural healing predicted better clinical outcomes at 1 year than mucosal healing (P = 0.01).

CONCLUSIONS

Transmural healing is an ambitious and powerful treatment goal associated, to a greater extent than mucosal healing, with improvement of all clinical outcomes. Additionally, transmural healing is associated with better long-term clinical outcomes than mucosal healing also after discontinuation of biologics.

Bowel Ultrasound State of the Art: Grayscale and Doppler Ultrasound, Contrast Enhancement, and Elastography in Crohn Disease

Bowel ultrasound (US) is accurate for assessing bowel inflammation and complications in Crohn disease. Additionally, contrast-enhanced US provides a quantitative, objective measurement of inflammatory activity in inflammatory bowel disease, and shear wave elastography predicts the stiffness of bowel, an increase of which suggests less response to medical therapy, often necessitating surgery. Overall, bowel US is an excellent, safe, and repeatable choice for routine surveillance and for urgent imaging. We describe an approach to evaluating inflammatory bowel disease and review its features on standard grayscale US with Doppler imaging and show how contrast-enhanced US and shear wave elastography can distinguish between inflammatory and fibrostenotic bowel.

Oral exclusive enteral nutrition induces mucosal and transmural healing in patients with Crohn's disease

Background and aims

Mucosal healing is regarded as a clinical endpoint of Crohn’s disease (CD), and transmural healing is correlated to the concept of deep remission. Current therapies to induce mucosal and transmural healing in CD are not satisfactory. Exclusive enteral nutrition (EEN) is underestimated therapy and its value has not been fully evaluated. Our aim was to investigate the efficacy of oral EEN for inducing mucosal and transmural healing in CD patients.

Methods

This was a prospective, single-center, open-label study including diagnosed CD children and adults conducted between January 2015 and December 2016 in the Sixth Affiliated Hospital of Sun Yat-sen University. All patients were treated with oral EEN and underwent paired assessment at baseline and completion using C-reaction protein, erythrocyte sedimentation rate, platelets, hemoglobin, body mass index, CD activity index, simple endoscopic score for CD and bowel sonography. Azathioprine was combined to prevent relapse.

Results

In this prospective observational study, 29 CD patients with an average age of 28.9 years were identified. After oral EEN treatment, 23 patients (79%) achieved complete mucosal healing, and the mean time to reach mucosal healing was 123 days (ranged from 50 to 212 days). Although only five patients (17%) achieved transmural healing, a significant reduction was observed in bowel-wall thickness (9.41 ± 3.06 vs 4.97 ± 1.76 mm, P < 0.001) and a significant improvement was observed in complications (including fistulas, abscess, ascites, stricture) assessed by bowel sonography (all P < 0.05).

Conclusions

Oral EEN therapy is highly effective for inducing mucosal healing in CD patients. Both CD patients at active stage and those at clinical remission show excellent clinical response to oral EEN.

Beyond appendicitis: ultrasound findings of acute bowel pathology

Bowel pathology is a common unexpected finding on routine abdominal and pelvic ultrasound. However, radiologists are often unfamiliar with the ultrasound appearance of the gastrointestinal tract due to the underutilization of ultrasound for bowel evaluation in the USA. The purpose of this article is to familiarize radiologists with the characteristic ultrasound features of a variety of bowel pathologies. Basic ultrasound technique for bowel evaluation, ultrasound appearance of normal bowel, and key ultrasound features of common acute bowel abnormalities will be reviewed.

Emergency Medicine Evaluation and Management of Small Bowel Obstruction: Evidence-Based Recommendations

BACKGROUND

Small bowel obstruction (SBO) is a commonly diagnosed disease in the emergency department (ED). Recent literature has evaluated the ED investigation and management of SBO.

OBJECTIVE

This review evaluates the ED investigation and management of adult SBO based on the current literature.

DISCUSSION

SBO is most commonly due to occlusion of the small intestine, resulting in fluid and gas accumulation. This may progress to mucosal ischemia, necrosis, and perforation. A variety of etiologies are present, but in adults, adhesions are the most common cause. Several classification systems are present. However, the most important distinction is complete vs. partial and complicated vs. simple obstruction, as complete complicated SBO more commonly requires surgical intervention. History and physical examination can vary, but the most reliable findings include prior abdominal surgery, history of constipation, abdominal distension, and abnormal bowel sounds. Signs of strangulation include fever, hypotension, diffuse abdominal pain, peritonitis, and several others. Diagnosis typically requires imaging, and though plain radiographs are often ordered, they cannot exclude the diagnosis. Computed tomography and ultrasound are reliable diagnostic methods. Management includes intravenous fluid resuscitation, analgesia, and determining need for operative vs. nonoperative therapy. Nasogastric tube is useful for patients with significant distension and vomiting by removing contents proximal to the site of obstruction. Surgery is needed for strangulation and those that fail nonoperative therapy. Surgical service evaluation and admission are recommended.

CONCLUSION

SBO is a common reason for admission from the ED. Knowledge of recent literature can optimize diagnosis and management.

Persistent Enhancement on Contrast-Enhanced Ultrasound Studies of Severe Crohn's Disease: Stuck Bubbles?

A small population of patients with severe Crohn's disease (CD) exhibit atypical lack of intensity decline on intestinal contrast-enhanced ultrasound. From a retrospective CD cohort examined with contrast-enhanced ultrasound, 104 patients were identified. Twenty study patients with severe active disease exhibited high peak enhancement (>23 dB) and minimal decline. From the same cohort, 84 control patients also exhibited high peak enhancement >23dB, but with typical intensity decline. Patient outcomes were assessed. Time-intensity curve analysis revealed a significantly higher (p < 0.0001) area under the curve (44.7 ± 1.5 dB·s), washout time and intensities at 60s and 120s in the study population compared with controls (40.0 ± 1.1 dB·s). Study patients had a worse overall outcome with surgery in 30% versus 10% (p = 0.027) during follow-up. Heightened enhancement with lack of decline on contrast-enhanced ultrasound suggests microbubbles are stuck within the inflamed bowel wall for an extended period. This observation occurs in patients with severe disease and a bad outcome.

Diagnostic accuracy of magnetic resonance enterography and small bowel ultrasound for the extent and activity of newly diagnosed and relapsed Crohn's disease (METRIC): a multicentre trial

BACKGROUND

Magnetic resonance enterography (MRE) and ultrasound are used to image Crohn's disease, but their comparative accuracy for assessing disease extent and activity is not known with certainty. Therefore, we did a multicentre trial to address this issue.

METHODS

We recruited patients from eight UK hospitals. Eligible patients were 16 years or older, with newly diagnosed Crohn's disease or with established disease and suspected relapse. Consecutive patients had MRE and ultrasound in addition to standard investigations. Discrepancy between MRE and ultrasound for the presence of small bowel disease triggered an additional investigation, if not already available. The primary outcome was difference in per-patient sensitivity for small bowel disease extent (correct identification and segmental localisation) against a construct reference standard (panel diagnosis). This trial is registered with the International Standard Randomised Controlled Trial, number ISRCTN03982913, and has been completed.

FINDINGS

284 patients completed the trial (133 in the newly diagnosed group, 151 in the relapse group). Based on the reference standard, 233 (82%) patients had small bowel Crohn's disease. The sensitivity of MRE for small bowel disease extent (80% [95% CI 72-86]) and presence (97% [91-99]) were significantly greater than that of ultrasound (70% [62-78] for disease extent, 92% [84-96] for disease presence); a 10% (95% CI 1-18; p=0·027) difference for extent, and 5% (1-9; p=0·025) difference for presence. The specificity of MRE for small bowel disease extent (95% [85-98]) was significantly greater than that of ultrasound (81% [64-91]); a difference of 14% (1-27; p=0·039). The specificity for small bowel disease presence was 96% (95% CI 86-99) with MRE and 84% (65-94) with ultrasound (difference 12% [0-25]; p=0·054). There were no serious adverse events.

INTERPRETATION

Both MRE and ultrasound have high sensitivity for detecting small bowel disease presence and both are valid first-line investigations, and viable alternatives to ileocolonoscopy. However, in a national health service setting, MRE is generally the preferred radiological investigation when available because its sensitivity and specificity exceed ultrasound significantly.

FUNDING

National Institute of Health and Research Health Technology Assessment.

Guidelines for the investigation of chronic diarrhoea in adults: British Society of Gastroenterology, 3rd edition

Chronic diarrhoea is a common problem, hence clear guidance on investigations is required. This is an updated guideline from 2003 for the investigations of chronic diarrhoea commissioned by the Clinical Services and Standards Committee of the British Society of Gastroenterology (BSG). This document has undergone significant revision in content through input by 13 members of the Guideline Development Group (GDG) representing various institutions. The GRADE system was used to appraise the quality of evidence and grading of recommendations.

New cross-sectional imaging in IBD

PURPOSE OF REVIEW

Cross-sectional imaging, namely ultrasound, CT and MR enterography, complements clinical and endoscopic monitoring of activity and complications in IBD, and emerging new radiological technologies may have clinical applications in the near future. This review offers an update on the potential role of these new imaging methods in the management of IBD.

RECENT FINDINGS

Specific MR techniques [diffusion-weighted imaging (DWI), diffusion kurtosis imaging (DKI) and magnetization transfer] allow accurate detection of inflammation (DWI and maybe DKI) and fibrosis (magnetization transfer) in Crohn's disease, without the need of intravenous gadolinium administration. ultrasonography developments (elastography, contrast-enhanced ultrasonography, small intestine contrast ultrasonography and multispectral optoacoustic tomography) are promising techniques for evaluation of fibrosis (elastography) and inflammation (contrast ultrasonography). Dose-reduction techniques in CT allow similar quality imaging and diagnostic accuracy with lower radiation exposure. Hybrid imaging (PET/MR and PET/CT) hold promise for grading inflammation in Crohn's disease.

SUMMARY

The potential benefits of new cross-sectional imaging techniques in IBD include better inflammation grading, such as identification of mild degree of activity, which may be relevant whenever assessing response to treatment and, of uttermost importance, accurate preoperative detection and grading of fibrosis in stricturing Crohn's disease, facilitating surgical vs. medical therapeutic decisions.

Combined Endoscopic/Sonographic-based Risk Matrix Model for Predicting One-year Risk of Surgery: A Prospective Observational Study of a Tertiary Centre Severe/Refractory Crohn's Disease Cohort

BACKGROUND

In the management of Crohn's disease [CD] patients, having a simple score combining clinical, endoscopic, and imaging features to predict the risk of surgery could help to tailor treatment more effectively.

AIMS

We aimed to prospectively evaluate the 1-year risk factors for surgery in refractory/severe CD and to generate a risk matrix for predicting the probability of surgery at 1 year.

METHODS

CD patients needing a disease re-assessment at our tertiary inflammatory bowel disease [IBD] centre underwent clinical, laboratory, endoscopic, and bowel sonography [BS] examinations within 1 week. The optimal cut-off values in predicting surgery were identified using receiver operating characteristic [ROC] curves for the Simple Endoscopic Score for CD [SES-CD], bowel wall thickness [BWT] at BS, and small bowel CD extension at BS. Binary logistic regression and Cox regression were then carried out. Finally, the probabilities of surgery were calculated for selected baseline levels of covariates and results were arranged in a prediction matrix.

RESULTS

Of 100 CD patients, 30 underwent surgery within 1 year. SES-CD ≥9 (odds ratio [OR] 15.3; p <0.001], BWT ≥7 mm [OR 15.8; p <0.001], small bowel CD extension at BS ≥33 cm [OR 8.23; p <0.001], and stricturing/penetrating behaviour [OR 4.3; p <0.001] were the only independent factors predictive of surgery at 1 year, based on binary logistic and Cox regressions. Our matrix model combined these risk factors, and the probability of surgery ranged from 0.48% to 87.5% [16 combinations].

CONCLUSIONS

Our risk matrix combining clinical, endoscopic, and ultrasonographic findings can accurately predict the 1-year risk of surgery in patients with severe/refractory CD requiring a disease re-evaluation. This tool could be of value in clinical practice, serving as the basis for a tailored management of CD patients.

Detecting inflammation in inflammatory bowel disease - how does ultrasound compare to magnetic resonance enterography using standardised scoring systems?

BACKGROUND

Magnetic resonance enterography (MRE) is the current gold standard for imaging in inflammatory bowel disease, but ultrasound (US) is a potential alternative.

OBJECTIVE

To determine whether US is as good as MRE for the detecting inflamed bowel, using a combined consensus score as the reference standard.

MATERIALS AND METHODS

We conducted a retrospective cohort study in children and adolescents <18 years with inflammatory bowel disease (IBD) at a tertiary and quaternary centre. We included children who underwent MRE and US within 4 weeks. We scored MRE using the London score and US using a score adapted from the METRIC (MR Enterography or Ultrasound in Crohn's Disease) trial. Four gastroenterologists assessed an independent clinical consensus score. A combined consensus score using the imaging and clinical scores was agreed upon and used as the reference standard to compare MRE with US.

RESULTS

We included 53 children. At a whole-patient level, MRE scores were 2% higher than US scores. We used Lin coefficient to assess inter-observer variability. The repeatability of MRE scores was poor (Lin 0.6). Agreement for US scoring was substantial (Lin 0.95). There was a significant positive correlation between MRE and clinical consensus scores (Spearman's rho = 0.598, P=0.0053) and US and clinical consensus scores (Spearman's rho = 0.657, P=0.0016).

CONCLUSION

US detects as much clinically significant bowel disease as MRE. It is possible that MRE overestimates the presence of disease when using a scoring system. This study demonstrates the feasibility of using a clinical consensus reference standard in paediatric IBD imaging studies.

Intestinal ultrasound and management of small bowel Crohn's disease

As Crohn's disease (CD) is predominantly located within the small bowel, imaging of the small bowel plays an intriguing role in the primary diagnosis as well as in the monitoring of patients with CD. Intestinal ultrasound (IUS) offers several advantages over endoscopy and other imaging modalities. Obvious advantages of IUS include noninvasiveness, rapid availability and cost effectiveness. IUS has been shown to have high accuracy in detecting small bowel CD and determining intra- and extramural complications such as stenoses, fistulae and abscesses. IUS has also been shown to be highly effective in determining postoperative disease recurrence and in follow up of patients under treatment. The following review summarizes current developments in the use of IUS for the detection of small bowel lesions and complications. The aim of this review is to suggest algorithms on how to use IUS in managing patients with small bowel CD in clinical practice. Suggested applications on the use of high frequency IUS in CD are extended by discussing new developments such as contrast-enhanced ultrasonography and elastography.

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.

Diagnostic Accuracy of Ultrasonography in the Detection of Postsurgical Recurrence in Crohn's Disease: A Systematic Review with Meta-analysis

BACKGROUND AND AIMS

The postoperative course of Crohn's disease (CD) is best predicted by ileocolonoscopy. Ultrasonography (US) has been proposed as indicator for postsurgical recurrence (PSR), but further confirmation is needed. We performed a systemic review with meta-analysis to assess the pooled diagnostic accuracy of US in the evaluation of PSR.

METHODS

The systematic review was performed in PubMed/MEDLINE, EMBASE, SCOPUS, and Cochrane databases to identify studies assessing the US accuracy in PSR diagnosis. A sub-analysis between bowel sonography (BS), small-intestine contrast ultrasound (SICUS), and contrast-enhanced ultrasound (CEUS) was performed. Pooling was performed using diagnostic fixed or random-effect model according with heterogeneity.

RESULTS

Ten studies (536 patients) met the inclusion criteria. There was no publication bias. Pooled sensitivity and specificity of US in detecting PSR were 0.94 (95% CI, 0.86-0.97) and 0.84 (95% CI, 0.62-0.94; diagnostic accuracy 90%), respectively. At sub-analysis, pooled sensitivity and specificity were 0.82 (95% CI, 0.76-0.88) and 0.88 (95% CI, 0.74-0.95) respectively for BS, with 0.99 (95% CI, 0.99-1.00) and 0.74 (95% CI, 0.73-0.74) for SICUS. Finally, an SROC curve was built to establish the best bowel wall thickness (BWT) cutoff able to predict the presence of severe PSR (Rutgeerts ≥3): a BWT ≥5.5 mm at US revealed sensitivity of 83.8% (95% CI, 73.6%-90.6%), specificity of 97.7% (95% CI, 93%-99%).

CONCLUSIONS

US shows high sensitivity and specificity for the diagnosis of PSR. SICUS appears more sensitive-but less specific-than BS, while the role of CEUS needs further investigation. A cutoff value of BWT ≥5.5 mm is strongly indicative of severe PSR. 10.1093/ibd/izy012_video1izy012.video15775249754001.

The accuracy of intestinal ultrasound compared with small bowel capsule endoscopy in assessment of suspected Crohn's disease in patients with negative ileocolonoscopy

BACKGROUND

Small bowel involvement in Crohn's disease (CD) is frequently proximal to the ileocecal valve and inaccessible by conventional ileocolonoscopy (IC). Small bowel capsule endoscopy (SBCE) is among the prime modalities for assessment of small bowel disease in these patients. Intestinal ultrasound (IUS) is an accurate bedside fast and low-cost diagnostic modality utilized in CD for both diagnosis and monitoring. The aim of this study was to examine the accuracy of IUS in patients with suspected CD after a negative IC, and to evaluate the correlation of IUS with SBCE, inflammatory biomarkers and other cross-sectional imaging techniques.

METHODS

Prospective single center study in which patients with suspected CD underwent IUS and SBCE examinations within 3 days. IUS results were blindly compared with SBCE that served as the gold standard. A post hoc comparison was performed of IUS and SBCE results and available cross-sectional imaging results (computed tomography or magnetic resonance enterography) as well as inflammatory biomarkers if measured. The study cohort was followed for 1 year. In case of discordance between the IUS and SBCE results, the diagnosis at 1 year was reported.

RESULTS

Fifty patients were included in the study. The diagnostic yield of both IUS and SBCE for the diagnosis of small bowel CD was 38%. The IUS findings significantly correlated to small bowel inflammation detected by SBCE (r = 0.532, p < 0.001), with fair sensitivity and specificity (72% and 84%). Cross-sectional imaging results significantly correlated to IUS as well (r = 0.46, p = 0.018). Follow up was available in 8 of the 10 cases of discordance between IUS and SBCE. In all of these cases, diagnosis of CD was not fully established at the end of the follow up.

CONCLUSIONS

The diagnostic yield of CE and IUS for detection of CD in patients with negative ileocolonoscopy was similar. IUS can be a useful diagnostic tool in suspected CD when IC is negative.

Role of contrast-enhanced ultrasound in evaluation of the bowel

Contrast-enhanced ultrasound (CEUS) of the gastrointestinal tract provides vascular information helpful for characterizing masses and other pathologies in and around the bowel, similar to contrast applications in other solid organs. However, the use of microbubble contrast agents for the bowel provides additional unique contributions as it gives both subjective and objective information about mural and mesenteric blood flow, invaluable for the determination of disease activity in those many patients affected by inflammatory bowel disease (IBD). IBD is a lifelong chronic disease and has its peak age of onset in adolescence or young adult life. Today, we have moved away from treating patient’s symptoms and strive instead to alter the course of disease by obtaining mucosal healing. Expensive and aggressive biologic therapies and lack of agreement of patient’s symptoms with their disease activity and complications necessitate frequent imaging surveillance, which must be safe, readily available, inexpensive, and effective. Ultrasound with the benefit of contrast enhancement meets these requirements and is shown in meta-analysis to be equivalent to CT and MRI scans for these indications.

Monitoring of small bowel Crohn's disease

In recent years, the therapeutic paradigm in Crohn's disease has shifted from a mere symptom-oriented approach, to aiming to healing of the underlying inflammation and prevention of long-term structural complications. Such 'treat-to-target' approach may allow for a more stable disease course with less hospitalizations, lower requirement for surgery and improved quality of life. In Crohn's disease, the small bowel is affected in the majority of patients; frequently, Crohn's involves only the small bowel, which remains inaccessible to conventional ileocolonoscopic techniques. Thus, non-invasive monitoring techniques are crucial for accurate disease assessment. Areas covered: This review addresses the indications and clinical implications of non-invasive small bowel monitoring modalities (magnetic resonance enterography, intestinal ultrasound, capsule endoscopy) in the assessment and management of Crohn's disease. Expert commentary: This review addresses the limitations of the current knowledge and future areas of research, including the possible utilization of transmural healing as an imaging target and the need to establish clear quantitative target values to guide treatment by imaging findings in Crohn's disease.

Cross-sectional evaluation of transmural healing in patients with Crohn's disease on maintenance treatment with anti-TNF alpha agents

BACKGROUND

Transmural healing (TH) of Crohn's disease (CD) is a still unexplored and interesting outcome correlated to concept of deep remission.

AIM

To assess the rate of TH in CD patients treated with anti-TNF alpha agents using two cross-sectional procedures: bowel sonography (BS) and magnetic resonance enterography (MRE).

METHODS

We performed a 2-year observational longitudinal study, evaluating steroid-free clinical remission (CR), mucosal healing (MH), and TH in CD patients who would complete a 2-year treatment period with anti-TNFs. All patients underwent endoscopy, BS, and MRE before and after 2 years of treatment.

RESULTS

Forty out of 80 CD patients were treated with anti-TNFs for 2 years. CR was achieved in 24 patients (60%) while MH in 14 (35%). Using BS, TH was observed in 10 patients (25%), while using MRE, TH was observed in 9 patients (23%) (k=0.90; P<0.01). A good agreement was observed between MH and TH, both using BS (k=0.63; P<0.01) and MRE (k=0.64; P<0.01). A poor agreement was found between CR and TH, with both BS and MRE (k=0.27 and 0.29, respectively; P<0.01); even though all patients with TH had achieved CR.

CONCLUSIONS

TH can be achieved in about 25% of CD patients treated with anti-TNFs, as shown by BS and MRE. BS could be used as the first cross-sectional procedure to detect TH.

Non-invasive evaluation of intestinal disorders: The role of elastographic techniques

Over the recent years the non-invasive techniques for the evaluation of the small bowel have been playing a major role in the management of chronic intestinal diseases, such as inflammatory bowel diseases (IBD). The diagnostic performances of magnetic resonance imaging, computed tomography and ultrasound in the field of small bowel disorders, have been assessed and established for more than two decades. Newer sonographic techniques, such as strain elastography and shear wave elastography, have been put forward for the assessment of disease activity and characterization of IBD-related damage in the setting of Crohn's disease and other gastrointestinal disorders. The data from the preliminary research and clinical studies have shown promising results as regards the ability of elastographic techniques to differentiate inflammatory from fibrotic tissue. The distinction between IBD activity (inflammation) and IBD-related damage (fibrosis) is currently considered crucial for the assessment and management of patients. Moreover, all the elastographic techniques are currently being considered in the setting of other intestinal disorders (e.g., rectal tumors, appendicitis). The aim of this paper is to offer both a comprehensive narrative review of the non-invasive techniques available for the assessment of small-bowel disorders, with particular emphasis on inflammatory bowel diseases, and a summary of the current evidence on the use of elastographic techniques in this setting.

Role of Bowel Ultrasound in the Diagnosis and Follow-up of Patients with Crohn's Disease

Crohn's disease (CD) is an inflammatory chronic bowel disorder; it can involve the whole gastrointestinal tract, but its localization in the ileum or colon is most common. The reference standard for the diagnosis of CD is ileocolonoscopy with histologic assessment. The reference standard for the detection of any complications is surgery. However, imaging techniques have an important role both in the detection/localization of CD and in the follow-up of CD patients. In the last few years, the technical development of ultrasound equipment, the advent of new technologies such as elastography and mostly the increased expertise of sonographers have boosted the role of bowel ultrasound in assessment of the gastrointestinal tract. In fact, bowel ultrasound is particularly attractive thanks to its widespread availability, non-invasiveness, low cost and good reproducibility, as it can be easily repeated during follow-up. The aim of this article is to provide an extensive overview of the actual role of bowel ultrasound in the detection and follow-up of patients with CD.

Ultrasound and MRI predictors of surgical bowel resection in pediatric Crohn disease

BACKGROUND

Imaging predictors for surgery in children with Crohn disease are lacking.

OBJECTIVE

To identify imaging features of the terminal ileum on short-interval bowel ultrasound (US) and MR enterography (MRE) in children with Crohn disease requiring surgical bowel resection and those managed by medical therapy alone.

MATERIALS AND METHODS

This retrospective study evaluated patients 18 years and younger with Crohn disease undergoing short-interval bowel US and MRE (within 2 months of one another), as well as subsequent ileocecectomy or endoscopy within 3 months of imaging. Appearance of the terminal ileum on both modalities was compared between surgical patients and those managed with medical therapy, with the following parameters assessed: bowel wall thickness, mural stratification, vascularity, fibrofatty proliferation, abscess, fistula and stricture on bowel US; bowel wall thickness, T2 ratio, enhancement pattern, mesenteric edema, fibrofatty proliferation, abscess, fistula and stricture on MRE. A two-sided t-test was used to compare means, a Mann-Whitney U analysis was used for non-parametric parameter scores, and a chi-square or two-sided Fisher exact test compared categorical variables. Imaging findings in surgical patients were correlated with location-matched histopathological scores of inflammation and fibrosis using a scoring system adapted from the Simple Endoscopic Score for Crohn Disease, and a Spearman rank correlation coefficient was used to compare inflammation and fibrosis on histopathology.

RESULTS

Twenty-two surgical patients (mean age: 16.5 years; male/female: 13/9) and 20 nonsurgical patients (mean age: 14.8; M/F: 8/12) were included in the final analysis. On US, the surgical group demonstrated significantly increased mean bowel wall thickness (6.1 mm vs. 4.7 mm for the nonsurgical group; P = 0.01), loss of mural stratification (odds ratio [OR] = 6.3; 95% confidence interval [CI]: 1.4-28.4; P = 0.02) and increased fibrofatty proliferation (P = 0.04). On MRE, the surgical group showed increased mean bowel wall thickness (9.1 mm vs. 7.2 mm for the nonsurgical group; P = 0.02), increased mean T2 ratio (4.6 vs. 3.6 for the nonsurgical group; P = 0.03), different enhancement patterns (P = 0.03), increased mesenteric edema (P = 0.001) and increased stricture formation (OR = 8.2; 95% CI: 1.8-36.4; P = 0.005). Nineteen of 22 ileocecectomy specimens showed severe inflammation and 21/22 showed severe fibrosis, with significant correlation between inflammation and fibrosis scores (ρ = 0.55; P = 0.008); however, correlation with imaging findings was limited by the uniformity of findings on histopathology.

CONCLUSION

Children with terminal ileal Crohn disease requiring surgical bowel resection demonstrate more severe manifestations of imaging features traditionally associated with both active inflammation and chronic fibrosis than those managed medically on US and MRE, findings that are corroborated by histopathology. These features may potentially serve as imaging biomarkers indicating the necessity for surgical intervention.

Bowel Damage in Crohn's Disease: Direct Comparison of Ultrasonography-based and Magnetic Resonance-based Lemann Index

BACKGROUND

The Lémann index (LI), calculated by magnetic resonance (MR) or computed tomography enterography in association with endoscopy, was developed to assess bowel damage (BD) in Crohn's disease (CD). Our aim was to investigate the concordance between ultrasonography-based Lèmann index (US-LI) and magnetic resonance-based Lèmann index (MR-LI).

METHODS

We prospectively evaluated all consecutive patients with CD referred to our IBD Unit. All patients had undergone endoscopy, US and MR within 1 month. US-LI and MR-LI were calculated by scoring previous surgery, location, extension, and intestinal complications. Furthermore, we evaluated the association between LI and: CD duration, Harvey-Bradshaw index, and other relevant clinical features. In accordance with recent literature, an LI >4.8 was considered indicative of BD.

RESULTS

Seventy-one patients with CD were examined. About CD location, 36% showed ileal disease (L1), 10% showed colonic CD (L2), whereas 54% had an ileocolonic disease (L3). Moreover, 27% of patients presented a noncomplicated behavior (B1), 45% had almost one stricture (B2), whereas 28% showed penetrating CD (B3). Perianal CD was observed in 16% of subjects, whereas 40% had undergone previous surgery. MR-LI and US-LI were 6.62 (95% confidence interval, 4.2-9.7) and 6.04 (95% confidence interval, 3.6-9.2), respectively (r = 0.90; P < 0.001), with 35 patients (49%) showing an LI indicative of BD. No significant correlation was evident between LI and Harvey-Bradshaw index (P = 0.9), whereas a significant correlation was found between both US-LI/MR-LI and CD duration (P = 0.01).

CONCLUSIONS

US-LI shows high concordance with MR-LI and could be considered a good option for assessing BD in CD by using a highly available and relatively inexpensive procedure.

Bowel Thickening in Crohn's Disease: Fibrosis or Inflammation? Diagnostic Ultrasound Imaging Tools

The high frequency of intestinal strictures in patients with Crohn's disease and the different treatment approaches specific for each type of stenosis make the differentiation between fibrotic and inflammatory strictures crucial in management of the disease. However, there is no standardized approach to evaluate and discriminate intestinal strictures, and until now, there was no established cross-sectional imaging modality to detect fibrosis. New techniques, such as contrast-enhanced ultrasound and sonoelastography allow the assessment of vascularization and mechanical properties of stenotic bowel tissue, respectively. These techniques have shown great potential to characterize strictures in Crohn's disease. The aim of this review is to sum up the current knowledge on bowel ultrasound tools to discriminate inflammatory from fibrotic stenosis in Crohn's disease considering the most recent published studies in the field.

The use of ultrasound in inflammatory bowel disease

Imaging in inflammatory bowel disease (IBD) plays a pivotal role in the primary diagnosis, as well as during the management of patients with known IBD. The evolution of ultrasound equipment and the growing expertise of examiners have both enhanced the role of intestinal ultrasound in the assessment of the gastrointestinal tract in IBD patients. Intestinal ultrasound has been shown to have high sensitivity and specificity, as well as high positive and negative predictive value, in the detection or exclusion of intestinal inflammatory activity in IBD. The obvious advantages of intestinal ultrasound over other imaging modalities include non-invasiveness, rapid availability and low costs. This review summarizes the current developments in the use of intestinal ultrasound for the detection of IBD and its complications, and discusses its use in the management of patients with IBD. Indications for the use of intestinal ultrasound in daily practice are presented, expanded by new developments such as contrast-enhanced ultrasonography and elastography.

Looking Beyond Mucosal Healing: Effect of Biologic Therapy on Transmural Healing in Pediatric Crohn's Disease

BACKGROUND

Crohn's disease is a chronic inflammatory disease characterized by a progressive transmural bowel damage leading to complications. Anti-TNFα therapy is effective in achieving mucosal healing (MH), but its efficacy on transmural inflammation has been poorly investigated. The aim of this study is to evaluate, in pediatric Crohn's disease, the efficacy of anti-tumor necrosis factor α agents in inducing transmural healing (TH) as assessed by ultrasonography (US).

METHODS

Children with Crohn's disease requiring anti-tumor necrosis factor α therapy were prospectively enrolled. Clinical activity, laboratory tests, endoscopic activity, and transmural disease assessed by small intestine contrast US (SICUS) were evaluated at baseline (T0) and then after 9 to 12 months of therapy (T1). We evaluated US quantitative and qualitative parameters: disease extension (centimeters), bowel wall (BW) thickness >3 mm, BW vascularity and stratification strictures, and prestenotic dilatation. TH was defined as a BW thickness <3 mm and normalization of all US parameters at T1.

RESULTS

Thirty-two patients were included. Patients with mucosal healing (MH) showed a significant decrease of BW thickness and disease extension at T1 (4.3 ± 1.4 mm and 8 ± 6.3 cm versus 6.1 ± 2.3 mm and 13 ± 5 cm at baseline, respectively) (P < 0.001). Increased vascularity of the BW was found in 80% of patients at T0 and in 18% at T1 (P < 0.001). These parameters did not change in patients without MH, despite clinical and laboratory remission. The presence of stenosis and prestenotic dilatation did not modify in any group. A complete TH was achieved in 14% of patients, all of them showing complete MH.

CONCLUSIONS

Biologics induce clinical and laboratory remission and MH in pediatric CD. Although caution is needed due to the small sample size, our data suggest that transmural inflammation also improves during therapy, but a complete TH is achieved only in a small percentage of patients.

Preliminary Analysis of Clinical Situations Involved in Quantification of Contrast-Enhanced Ultrasound in Crohn's Disease

To assess influencing factors for quantitative analysis of contrast-enhanced ultrasound (CEUS) in Crohn's disease (CD), dynamic CEUS examinations from 77 consecutive CD patients were recorded. Peak intensity (PI) values were calculated using the pre-installed quantification software of the ultrasound scanner. The influence of depth, pressure from the ultrasound probe and intraluminal gas was analyzed. The PI value of the anterior wall was lower than that of the posterior wall when the depth was ≤3.4 cm (17.9 dB vs. 21.3 dB; p < 0.05) or evident pressure was exerted (19.1 dB vs. 22.5 dB; p < 0.01). In the presence of intraluminal gas, the PI of the anterior wall was higher than that of the posterior wall (20.7 dB vs. 18.8 dB; p < 0.05). Nevertheless, no significant difference was found between the PI value of anterior and posterior walls when the depth was >3.4 cm (19.8 dB vs. 20.3 dB), moderate pressure was exerted (20.5 dB vs. 21.1 dB) or luminal gas was excluded between the two bowel walls (18.9 dB vs. 21.2 dB; p ≥ 0.05). The factors of depth, pressure from the ultrasound probe and intraluminal gas can affect the quantification results of CEUS. It is preferable to place the region of interest in the posterior wall when luminal gas is absent and in the anterior wall when luminal gas is present. In the latter case, more attention should be paid to reducing pressure by the ultrasound probe.

ACR Appropriateness Criteria Crohn Disease

Crohn disease is a chronic inflammatory disorder involving the gastrointestinal tract, characterized by episodic flares and times of remission. Underlying structural damage occurs progressively, with recurrent bouts of inflammation. The diagnosis and management of this disease process is dependent on several clinical, laboratory, imaging, endoscopic, and histologic factors. In recent years, with the maturation of CT enterography, and MR enterography, imaging has played an increasingly important role in relation to Crohn Disease. In addition to these specialized examination modalities, ultrasound and routine CT have potential uses. Fluoroscopy, radiography, and nuclear medicine may be less beneficial depending on the clinical scenario. The imaging modality best suited to evaluating this disease may change, depending on the target population, severity of presentation, and specific clinical situation. This document presents seven clinical scenarios (variants) in both the adult and pediatric populations and rates the appropriateness of the available imaging options. They are summarized in a consolidated table, and the underlying rationale and supporting literature are presented in the accompanying narrative. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Particularities of Crohn's disease in pediatric patients: current status and perspectives regarding imaging modalities

A consensus on the best imaging modality evaluating inflammatory bowel disease in the pediatric population is lacking and it is often unclear which modality to choose in specific clinical circumstances. Children with inflammatory bowel disease are exposed to ionizing radiation from multiple imaging studies performed at initial diagnosis, throughout treatment and during the follow-up period. This paper discusses the value of different imaging techniques in pediatric patients with inflammatory bowel disease and gives a review of the literature. In addition, particular features of inflammatory bowel disease in children including the predilection of affected segments in the gastrointestinal tract are highlighted. Based on current literature knowledge, we encourage an integrative approach to the interpretation of clinical and imaging data for diagnosis and follow-up in daily clinical settings.

Considerations in Imaging Among Emergency Department Patients With Inflammatory Bowel Disease

Patients with inflammatory bowel disease who experience abdominal pain and gastrointestinal symptoms often seek care in the emergency department (ED). These patients commonly undergo abdominopelvic computed tomography (CT) as part of their evaluation, and the rate of imaging appears to be increasing without a corresponding increase in identification of clinically actionable findings or effect on disposition. Studies demonstrate that the yield of CT tends to be fairly high. Yet, because inflammatory bowel disease is often diagnosed at an early age, these patients are repeatedly imaged during their lifetime, a subset of whom accumulate high levels of ionizing radiation exposure, increasing their risk of cancer. This compounds an already increased risk of cancer in these patients because of inflammatory bowel disease alone. Lack of intimate knowledge of a patient's disease phenotype and disease progression contributes to uncertainty in distinguishing between an inflammatory exacerbation; a complication such as obstruction, abscess, perforation, fistula, or stricture; and a noninflammatory-bowel-disease-related condition. This uncertainty can lead to overuse of imaging with CT. Limited availability of and lack of awareness of alternate imaging modalities and strategies may prevent providers from pursuing strategies that avoid ionizing radiation. In this article, we review options for imaging inflammatory bowel disease patients in the ED and attempts undertaken to risk stratify these patients, and we discuss ways in which details of a patient's disease might guide imaging decisionmaking.

Quantitative Contrast-Enhanced Ultrasound Parameters in Crohn Disease: Their Role in Disease Activity Determination With Ultrasound

OBJECTIVE

The primary objective of our study was to examine the association between contrast-enhanced ultrasound (CEUS) parameters and established gray-scale ultrasound with color Doppler imaging (CDI) for the determination of disease activity in patients with Crohn disease. Our secondary objective was to develop quantitative time-signal intensity curve thresholds for disease activity.

MATERIALS AND METHODS

One hundred twenty-seven patients with Crohn disease underwent ultrasound with CDI and CEUS. Reviewers graded wall thickness, inflammatory fat, and mural blood flow as showing remission or inflammation (mild, moderate, or severe). If both gray-scale ultrasound and CDI predicted equal levels of disease activity, the studies were considered concordant. If ultrasound images suggested active disease not supported by CDI findings, the ultrasound results for disease activity were indeterminate. Time-signal intensity curves from CEUS were acquired with calculation of peak enhancement (PE), and AUCs. Interobserver variation and associations between PE and ultrasound parameters were examined. Multiclass ROC analysis was used to develop CEUS thresholds for activity.

RESULTS

Ninety-six (76%) studies were concordant, 19 of which showed severe disease, and 31 (24%) studies were indeterminate. Kappa analyses revealed good interobserver agreement on grades for CDI (κ = 0.76) and ultrasound (κ = 0.80) assessments. PE values on CEUS and wall thickness showed good association with the Spearman rank correlation coefficient for the entire population (ρ = 0.62, p < 0.01) and for the concordant group (ρ = 0.70, p < 0.01). Multiclass ROC analyses of the concordant group using wall thickness alone as the reference standard showed cutoff points of 18.2 dB for differentiating mild versus moderate activity (sensitivity, 89.0% and specificity, 87.0%) and 23.0 dB for differentiating moderate versus severe (sensitivity, 90% and specificity, 86.8%). Almost identical cutoff points were observed when using ultrasound global assessment as the reference standard: using 18.2 dB to differentiate mild versus moderate activity yielded sensitivity of 89.2% and specificity of 90.9% and using 22.9 dB to differentiate moderate versus severe activity yielded sensitivity of 89.5% and specificity of 83.1%.

CONCLUSION

Quantitative CEUS parameters integrated into inflammatory assessments with ultrasound reduce indeterminate results and improve disease activity level determinations.

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.

Bowel ultrasound imaging in patients with cystic fibrosis: Relationship with clinical symptoms and CFTR genotype

BACKGROUND

Ultrasound imaging is used to assess bowel abnormalities in gastrointestinal diseases. We aimed to assess the rate of predefined bowel ultrasound signs and their relationship with gastrointestinal symptoms and the cystic fibrosis transmembrane conductance regulator (CFTR) genotype in cystic fibrosis patients in regular follow-up.

METHODS

Prospective study of 70 consecutive patients with cystic fibrosis and 45 controls who underwent abdominal ultrasound; pertinent findings were related to gastrointestinal symptoms and, in cystic fibrosis patients, to pancreatic status, malabsorption degree, lipase intake, CFTR genotype (classified as severe or mild against functional class of CFTR mutations).

RESULTS

96% patients showed at least one abnormal bowel ultrasound sign. Most frequent signs were lymph node enlargement (64%), bowel loop dilatation (55%), thick corpuscular intraluminal content (49%), bowel wall hypervascularization (26%), thickened bowel wall (22%) and intussusception (17%). Patients with recurrent abdominal pain showed more bowel wall hypervascularization than patients without recurrent pain (47% vs. 19%, respectively; p = 0.02) and intussusception (58% vs. 17%, respectively; p < 0.01). Genotype was not associated to specific bowel ultrasound signs. Patients with bowel loop intussusception showed greater lipase intake than those without intussusception (8.118 ± 2.083 vs. 5.994 ± 4.187, respectively; p < 0.01).

CONCLUSION

Cystic fibrosis patients present a higher rate of bowel ultrasound abnormalities than controls. Bowel ultrasound abnormalities are associated with abdominal symptoms.

US of gastrointestinal tract disease

The potential use of ultrasonography (US) in evaluating gut disease has been underappreciated in most diagnostic imaging departments in North America. The impression that US has a questionable role in bowel assessment is related to the operator-dependent nature of the modality, the technical challenges of performing bowel US examinations, and the lack of familiarity of radiologists and technologists with the US appearances of normal and abnormal bowel. However, with development of technical experience by the sonographer and integration of a clinical focus at patient evaluation, US can become a powerful tool for bowel assessment. Unlike computed tomography and magnetic resonance imaging, it provides a widely available, noninvasive, inexpensive method for evaluating the gut without the use of ionizing radiation. These factors are of particular importance in young patients and those who require recurrent follow-up imaging. Because US is performed with real-time imaging, the modality also allows the sonographer to view and assess the motility properties of the bowel, a feature that has not been previously used to its full potential. Color Doppler US can yield useful information about mural vascularity in bowel disease when used in conjunction with gray-scale findings and clinical symptoms. Radiologists should be familiar with the static and dynamic US appearances of the normal and abnormal bowel, recognize features of various pathologic conditions, and understand potential errors at imaging interpretation. Online supplemental material is available for this article.

The role of endoscopy in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a group of chronic immune-mediated disorders of the gastrointestinal tract. It is often the result of the interaction of genetic and environmental factors. The role of endoscopy in disease surveillance is unprecedented. However, there is considerable debate in therapeutic goals in IBD patients, ranging from the resolution of clinical symptoms to mucosal healing. Furthermore, deep remission has recently been advocated for altering disease course in these patients. Additionally, neoplasia continues to be a significant cause of morbidity and mortality in IBD patients. This review discussed the role of several endoscopic techniques in assessing mucosal healing and neoplasia with emphasis on novel non-invasive endoscopic techniques.

Bowel Ultrasonography in Inflammatory Bowel Disease

BACKGROUND

The diagnosis of inflammatory bowel disease (IBD) is based on a combination of endoscopic, clinical and biochemical investigations as well as cross-sectional imaging. The applications of cross-sectional imaging in IBD are manifold. Ultrasonography has emerged as an important imaging modality in the diagnosis of Crohn's disease (CD) as well as for monitoring disease progression and in the therapeutic response to CD and ulcerative colitis (UC). Key Messages: Ultrasonography is non-invasive, radiation free, cheap, easy to use and well tolerated and accepted by patients. Bowel ultrasonography can be used for the primary diagnosis of CD as it has a similar sensitivity and specificity like that of MRI and CT, particularly in the case of CD. Ultrasonography can also be used to monitor treatment response to therapy and to detect disease recurrence of CD as well as UC. In CD, ultrasonography can also be used to detect complications such as strictures as well as extramural complications, including abscesses and fistulas. Contrast-enhanced ultrasonography is a useful tool that might be helpful to detect certain indications in CD, in particular the differentiation between abscesses and inflammation.

CONCLUSION

A variety of advantages of bowel ultrasonography over other imaging modalities suggest the more frequent use of this method to manage IBD patients in daily practice. Bowel ultrasonography should be a standard tool in IBD centers.