Benefit of computed tomography enterography in Crohn's disease: effects on patient management and physician level of confidence

Artificial Intelligence for Quantifying Cumulative Small Bowel Disease Severity on CT-Enterography in Crohn's Disease

INTRODUCTION

Assessing the cumulative degree of bowel injury in ileal Crohn's disease (CD) is difficult. We aimed to develop machine learning (ML) methodologies for automated estimation of cumulative ileal injury on computed tomography-enterography (CTE) to help predict future bowel surgery.

METHODS

Adults with ileal CD using biologic therapy at a tertiary care center underwent ML analysis of CTE scans. Two fellowship-trained radiologists graded bowel injury severity at granular spatial increments along the ileum (1 cm), called mini-segments. ML segmentation methods were trained on radiologist grading with predicted severity and then spatially mapped to the ileum. Cumulative injury was calculated as the sum (S-CIDSS) and mean of severity grades along the ileum. Multivariate models of future small bowel resection were compared with cumulative ileum injury metrics and traditional bowel measures, adjusting for laboratory values, medications, and prior surgery at the time of CTE.

RESULTS

In 229 CTE scans, 8,424 mini-segments underwent analysis. Agreement between ML and radiologists injury grading was strong (κ = 0.80, 95% confidence interval 0.79-0.81) and similar to inter-radiologist agreement (κ = 0.87, 95% confidence interval 0.85-0.88). S-CIDSS (46.6 vs 30.4, P = 0.0007) and mean cumulative injury grade scores (1.80 vs 1.42, P < 0.0001) were greater in CD biologic users that went to future surgery. Models using cumulative spatial metrics (area under the curve = 0.76) outperformed models using conventional bowel measures, laboratory values, and medical history (area under the curve = 0.62) for predicting future surgery in biologic users.

DISCUSSION

Automated cumulative ileal injury scores show promise for improving prediction of outcomes in small bowel CD. Beyond replicating expert judgment, spatial enterography analysis can augment the personalization of bowel assessment in CD.

Machine learning methods in automated detection of CT enterography findings in Crohn's disease: A feasibility study

PURPOSE

Qualitative findings in Crohn's disease (CD) can be challenging to reliably report and quantify. We evaluated machine learning methodologies to both standardize the detection of common qualitative findings of ileal CD and determine finding spatial localization on CT enterography (CTE).

MATERIALS AND METHODS

Subjects with ileal CD and a CTE from a single center retrospective study between 2016 and 2021 were included. 165 CTEs were reviewed by two fellowship-trained abdominal radiologists for the presence and spatial distribution of five qualitative CD findings: mural enhancement, mural stratification, stenosis, wall thickening, and mesenteric fat stranding. A Random Forest (RF) ensemble model using automatically extracted specialist-directed bowel features and an unbiased convolutional neural network (CNN) were developed to predict the presence of qualitative findings. Model performance was assessed using area under the curve (AUC), sensitivity, specificity, accuracy, and kappa agreement statistics.

RESULTS

In 165 subjects with 29,895 individual qualitative finding assessments, agreement between radiologists for localization was good to very good (κ = 0.66 to 0.73), except for mesenteric fat stranding (κ = 0.47). RF prediction models had excellent performance, with an overall AUC, sensitivity, specificity of 0.91, 0.81 and 0.85, respectively. RF model and radiologist agreement for localization of CD findings approximated agreement between radiologists (κ = 0.67 to 0.76). Unbiased CNN models without benefit of disease knowledge had very similar performance to RF models which used specialist-defined imaging features.

CONCLUSION

Machine learning techniques for CTE image analysis can identify the presence, location, and distribution of qualitative CD findings with similar performance to experienced radiologists.

Endoscopic Skipping, Stricturing, and Penetrating Complications in Crohn's Disease on Tandem Ileo-colonoscopy and Cross-sectional Imaging: A Retrospective Cohort Study

BACKGROUND

Crohn's disease (CD) is characterized by discontinuous inflammation. Failure to identify skipping lesions of the terminal ileum (TI) or transmural changes can lead to incorrect management.

METHODS

Eligible adult patients with CD undergoing ileo-colonoscopy and computed tomography enterography or magnetic resonance enterography within 6 months. We determined the prevalence of endoscopic skipping (normal ileum on colonoscopy but proximal small bowel inflammation on cross-sectional imaging), skip lesions (discontinuous inflammation along the gastrointestinal tract identified on cross-sectional imaging), structuring, and penetrating complications.

RESULTS

Among 202 patients, 45 (22.3%) had endoscopic skipping proximal to TI intubation. Fifty patients (24.5%) had small bowel skip lesions, primarily in the ileum. Strictures were identified in 34 patients (16.8%) through both imaging and ileo-colonoscopy, in 21 patients (10.4%) solely through cross-sectional imaging, and in 3 patients (1.5%) solely through ileo-colonoscopy. Approximately 36.2% of stricturing cases would be missed without cross-sectional imaging. Penetrating complications, including abscesses (2.5%) and various fistula types (4.9%), were detected in 15 (7.4%) patients.

CONCLUSIONS

Ileo-colonoscopy missed detection of active CD in approximately one-fifth of cases due to more proximal disease location. Stricturing disease might be missed in more than a third of cases if cross-sectional imaging is not performed.

Reliability of CT Enterography for Describing Fibrostenosing Crohn Disease

Background Standardized methods to measure and describe Crohn disease strictures at CT enterography are needed to guide clinical decision making and for use in therapeutic studies. Purpose To assess the reliability of CT enterography features to describe Crohn disease strictures and their correlation with stricture severity. Materials and Methods A retrospective study was conducted in 43 adult patients with symptomatic terminal ileal Crohn disease strictures who underwent standard-of-care CT enterography at a tertiary care center at the Cleveland Clinic between January 2008 and August 2016. After training on standardized definitions, four abdominal radiologists blinded to all patient information assessed imaging features (seven continuous measurements and nine observations) of the most distal ileal stricture in two separate sessions (separated by ≥2 weeks) in random order. Features with an interrater intraclass correlation coefficient (ICC) of 0.41 or greater (ie, moderate reliability or better) were considered reliable. Univariable and multivariable linear regression analysis identified reliable features associated with a visual analog scale of overall stricture severity. Significant reliable features were assessed as components of a CT enterography-based model to quantitate stricture severity. Results Examinations in 43 patients (mean age, 52 years ± 16 [SD]; 23 female) were evaluated. Five continuous measurements and six observations demonstrated at least moderate interrater reliability (interrater ICC range, 0.42 [95% CI: 0.25, 0.57] to 0.80 [95% CI: 0.67, 0.88]). Of these, 10 were univariably associated with stricture severity, and three continuous measurements-stricture length (interrater ICC, 0.64 [95% CI: 0.42, 0.81]), maximal associated small bowel dilation (interrater ICC, 0.80 [95% CI: 0.67, 0.88]), and maximal stricture wall thickness (interrater ICC, 0.50 [95% CI: 0.34, 0.62])-were independently associated (P value range, <.001 to .003) with stricture severity in a multivariable model. These three measurements were used to derive a well-calibrated (optimism-adjusted calibration slope = 1.00) quantitative model of stricture severity. Conclusion Standardized CT enterography measurements and observations can reliably describe terminal ileal Crohn disease strictures. Stricture length, maximal associated small bowel dilation, and maximal stricture wall thickness are correlated with stricture severity. © RSNA, 2024 Supplemental material is available for this article. See also the article by Rieder et al in this issue. See also the editorial by Galgano and Summerlin in this issue.

Reliability of MR Enterography Features for Describing Fibrostenosing Crohn Disease

Background Clinical decision making and drug development for fibrostenosing Crohn disease is constrained by a lack of imaging definitions, scoring conventions, and validated end points. Purpose To assess the reliability of MR enterography features to describe Crohn disease strictures and determine correlation with stricture severity. Materials and Methods A retrospective study of patients with symptomatic terminal ileal Crohn disease strictures who underwent MR enterography at tertiary care centers (Cleveland Clinic: September 2013 to November 2020; Mayo Clinic: February 2008 to March 2019) was conducted by using convenience sampling. In the development phase, blinded and trained radiologists independently evaluated 26 MR enterography features from baseline and follow-up examinations performed more than 6 months apart, with no bowel resection performed between examinations. Follow-up examinations closest to 12 months after baseline were selected. Reliability was assessed using the intraclass correlation coefficient (ICC). In the validation phase, after five features were redefined, reliability was re-estimated in an independent convenience sample using baseline examinations. Multivariable linear regression analysis identified features with at least moderate interrater reliability (ICC ≥0.41) that were independently associated with stricture severity. Results Ninety-nine (mean age, 40 years ± 14 [SD]; 50 male) patients were included in the development group and 51 (mean age, 45 years ± 16 [SD]; 35 female) patients were included in the validation group. In the development group, nine features had at least moderate interrater reliability. One additional feature demonstrated moderate reliability in the validation group. Stricture length (ICC = 0.85 [95% CI: 0.75, 0.91] and 0.91 [95% CI: 0.75, 0.96] in development and validation phase, respectively) and maximal associated small bowel dilation (ICC = 0.74 [95% CI: 0.63, 0.80] and 0.73 [95% CI: 0.58, 0.87] in development and validation group, respectively) had the highest interrater reliability. Stricture length, maximal stricture wall thickness, and maximal associated small bowel dilation were independently (regression coefficients, 0.09-3.97; P < .001) associated with stricture severity. Conclusion MR enterography definitions and scoring conventions for reliably assessing features of Crohn disease strictures were developed and validated, and feature correlation with stricture severity was determined. © RSNA, 2024 Supplemental material is available for this article. See also the article by Rieder and Ma et al in this issue. See also the editorial by Galgano and Summerlin in this issue.

Residual abnormalities on CTE predict adverse outcomes in Crohn's disease with endoscopic healing

BACKGROUND

Residual abnormalities on computed tomography enterography (CTE) in Crohn's disease (CD) with endoscopic healing (EH) may have prognostic implications and affect therapeutic strategy.

METHODS

CD patients with EH who underwent CTE between March 2015 and June 2022 were enrolled. CTE findings of the terminal ileum and the most severe segment of colon at the time of EH were assessed respectively for each patient. Cox regression analysis and Kaplan-Meier curves were used to evaluate the association between residual abnormalities and adverse outcomes.

RESULTS

A total of 140 patients (217 digestive segments) were included. Mesenteric edema (hazard ratio [HR] = 3.61, 95% CI = 1.81-7.20, P<0.001), fibrofatty proliferation (HR = 3.40, 95% CI = 1.97-5.85, P<0.001) and active small bowel inflammation (HR = 2.74, 95% CI = 1.59-4.71, P<0.001) were risk factors for clinical relapse. Furthermore, we built a scoring system using the three parameters. Radiologic score ≥ 1 was the best threshold to predict clinical relapse (HR = 4.56, 95% CI = 2.54-8.19, P<0.001) and it was validated in different outcomes.

CONCLUSION

The scoring system based on three residual abnormalities on CTE can predict adverse outcomes in CD patients with EH.

Development and validation of multiparametric models based on computed tomography enterography to determine endoscopic activity and surgical risk in patients with Crohn's disease: A multi-center study

Objective

To develop novel multiparametric models based on computed tomography enterography (CTE) scores to identify endoscopic activity and surgical risk in patients with Crohn's disease (CD).

Methods

We analyzed 171 patients from 3 hospitals. Correlations between CTE outcomes and endoscopic scores were assessed using Spearman's rank correlation analysis. Predictive models for moderate to severe CD were developed, and receiver operating characteristic (ROC) curves were constructed to determine the area under the ROC curve (AUC). A combined nomogram based on CTE scores and clinical variables was also developed for predicting moderate to severe CD and surgery.

Results

CTE scores were significantly correlated with endoscopy scores at the segment level. The global CTE score was an independent predictor of severe (HR = 1.231, 95% CI: 1.048-1.446, p = 0.012) and moderate-to-severe Simplified Endoscopic Scores for Crohn's Disease (SES-CD) (HR = 1.202, 95% CI: 1.090-1.325, p < 0.001). The nomogram integrating CTE and clinical data predicted moderate to severe SES-CD and severe SES-CD scores in the validation cohort with AUCs of 0.837 and 0.807, respectively. The CTE score (HR = 1.18; 95% CI: 1.103-1.262; p = 0.001) and SES-CD score (HR = 3.125, 95% CI: 1.542-6.33; p = 0.001) were independent prognostic factors for surgery-free survival. A prognostic nomogram incorporating CTE scores, SES-CD and C-reactive protein (CRP) accurately predicted the risk of surgery in patients with CD.

Conclusion

The newly developed CTE score and multiparametric models displayed high accuracy in predicting moderate to severe CD and surgical risk for CD patients.

Evaluation of symptomatic small bowel stricture in Crohn's disease by double-balloon endoscopy

PURPOSE

To assess the efficacy of double-balloon endoscopy (DBE) for the detection of small-bowel strictures in Crohn's disease (CD).

METHODS

This tertiary-referral hospital cohort study was conducted between January 2018 and May 2022. CD patients with symptoms of small-bowel stricture were enrolled sequentially. All of the patients were subjected to both computed tomography enterography (CTE) and DBE, and their symptoms of stricture were assessed using the Crohn's Disease Obstructive Score (CDOS). The diagnostic yield of DBE was compared to that of CTE, and the relationship between the DBE findings and CDOS was investigated. The factors influencing the DBE diagnosis were examined using Cox regression analysis.

RESULTS

This study included 165 CD patients. The CDOS scores were higher in 95 patients and lower in 70 patients. DBE detected 92.7% (153/165) and CTE detected 85.5% (141/165) of the strictures. The DBE diagnostic yields were 94.7% (90/95) in the high CDOS patients and 91.4% (64/70) in the low CDOS patients (P = 0.13). Patients with a history of abdominal surgery and abscess had a lower diagnosis rate in the multivariate analysis.

CONCLUSION

DBE has been demonstrated to be an efficient diagnostic method for detecting small bowel strictures in CD patients. Additionally, there was no difference in the diagnostic yields between patients with low and high obstructive scores.

Crohn's disease active inflammation assessment with iodine density from dual-energy CT enterography: comparison with endoscopy and conventional interpretation

PURPOSE

To compare terminal ileum (TI) mucosal iodine density obtained at dual-energy CT enterography (DECTE) with conventional CT interpretation and endoscopy in patients with Crohn's disease (CD).

MATERIALS AND METHODS

Twenty-three CD patients (14 men; mean[SD] age:48.1[16.7] years) with endoscopy within 30 days of DECTE were retrospectively identified. An inflammatory bowel disease gastroenterologist reviewed endoscopic images. Two radiologists qualitatively assessed the presence of active TI inflammation. Mean iodine density normalized to the aorta (I%), mean absolute iodine density (I), and iodine density standard deviation (I_SD) from the distal 2 cm ileum (TI) mucosa obtained using semiautomatic prototype software were compared with endoscopic assessment using Mann Whitney tests. The optimal threshold I% and I were determined from receiver operating curves (ROC). Sensitivity and specificity of conventional interpretation and determined iodine thresholds were compared using McNemar's test. Inter-reader agreement was assessed using kappa. A p < 0.05 indicated statistical significance.

RESULTS

Twelve (52.1%) patients had endoscopic active inflammation. I% was 37.9[13.3]% for patients with and 21.7[7.5]% for patients without endoscopic active inflammation (p = 0.001). The optimal ROC threshold 24.6% had 100% sensitivity and 81.8% specificity (AUC = 0.909, 95% CI 0.777-1). I was 2.44[0.73]mg/mL for patients with and 1.77[1.00]mg/mL for patients without active endoscopic inflammation (p = 0.0455). The optimal ROC threshold 1.78 mg/mL I had 91.7% sensitivity and 63.6% specificity (AUC = 0.75, 95% CI 0.532-0.968). I_SD was similar for patients with and without endoscopic active inflammation (0.82[0.33]mg/mL and 0.77[0.28]mg/mL, respectively, p = 0.37). Conventional interpretation sensitivity and specificity (R1/R2) were 83.3%/91.7% and 72.7%/54.5%, respectively (all p > 0.05) with moderate inter-reader agreement (Κ = 0.542[95% CI 0.0202-0.088]).

CONCLUSION

Mean normalized iodine density is highly sensitive and specific for endoscopic active inflammation. DECTE could be considered as a surrogate to endoscopy in CD patients. Despite trends towards improved sensitivity and specificity compared with conventional interpretation, future larger studies are needed.

Small bowel Crohn's disease: optimal modality for diagnosis and monitoring

PURPOSE OF REVIEW

This paper reviews different imaging options for small bowel (SB) Crohn's disease (CD) patients.

RECENT FINDINGS

In total, 80% of patients suffering from CD have SB involvement, being the exclusive manifestation in 30% of cases. As the proximal disease is related to poor response to treatment, a higher rate of stenosis and a greater need for surgical treatment, a SB assessment should be performed. This evaluation should be done not only once the disease has been diagnosed but periodically. The former to determine the extent of the disease, and the latter according to a treat-to-target strategy. Available techniques such as magnetic resonance imaging, intestinal ultrasound and capsule endoscopy (CE) have shown good accuracy parameters in CD patients. Cross-sectional studies are superior for penetrating and stricturing disease, whereas CE is excellent for proximal involvement and mucosal healing. Local expertise and availability may lead the election between techniques, nevertheless, they should not be considered as competitors but as complementary tools.

SUMMARY

SB involvement in CD patients is frequent and related to poorer outcomes. Hence, SB evaluation should be screened after diagnosis and routinely during the follow-up.

Computed tomography enterography for crohn's disease: correlation between the imaging findings and histopathologic scoring system

OBJECTIVES

The aim of this study was to retrospectively determine if quantitative measurements of computed tomography enterography (CTE) imaging findings correlate with histopathologic scores from biopsy specimens in patients with Crohn's disease (CD).

METHODS

CTE datasets of 34 CD patients (19 male and 15 female) who underwent endoscopy with biopsy within 25 days before or after CTE were retrospectively reviewed. CTE findings of segmental mural hyperenhancement, wall thickening, mural stratification and mesenteric findings were quantitatively measured in the corresponding segment. Histopathologic score of CD was based upon the Naini Cortina scoring system. Correlation between CTE findings and histopathologic scores was assessed using Spearman's rank correlation and logistic or linear regression analysis.

RESULTS

Neutrophilic inflammation contributed the most to the segmental mural hyperenhancement and explained 38.4% of the variance (R² = 0.384, P = 0.006). Moreover, the increased lymphocytes and plasma cells predicted larger lymph node (P = 0.003) and increased attenuation in mesenteric fat (P = 0.022).

CONCLUSIONS

To a certain extent, macroscopic CTE findings may reflect the microscopic histopathologic state in the inflammatory stage of CD, underscoring that establishment of CTE scoring system may potentially provide an objective tool for assessment of disease progression.

Assessing Small Bowel Stricturing and Morphology in Crohn's Disease Using Semi-automated Image Analysis

BACKGROUND

Evaluating structural damage using imaging is essential for the evaluation of small intestinal Crohn's disease (CD), but it is limited by potential interobserver variation. We compared the agreement of enterography-based bowel damage measurements collected by experienced radiologists and a semi-automated image analysis system.

METHODS

Patients with small bowel CD undergoing a CT-enterography (CTE) between 2011 and 2017 in a tertiary care setting were retrospectively reviewed. CT-enterography studies were reviewed by 2 experienced radiologists and separately underwent automated computer image analysis using bowel measurement software. Measurements included maximum bowel wall thickness (BWT-max), maximum bowel dilation (DIL-max), minimum lumen diameter (LUM-min), and the presence of a stricture. Measurement correlation coefficients and paired t tests were used to compare individual operator measurements. Multivariate regression was used to model identification of strictures using semi-automated measures.

RESULTS

In 138 studies, the correlation between radiologists and semi-automated measures were similar for BWT-max (r = 0.724, 0.702), DIL-max (r = 0.812, 0.748), and LUM-min (r = 0.428, 0.381), respectively. Mean absolute measurement difference between semi-automated and radiologist measures were no different from the mean difference between paired radiologists for BWT-max (1.26 mm vs 1.12 mm, P = 0.857), DIL-max (2.78 mm vs 2.67 mm, P = 0.557), and LUM-min (0.54 mm vs 0.41 mm, P = 0.596). Finally, models of radiologist-defined intestinal strictures using automatically acquired measurements had an accuracy of 87.6%.

CONCLUSION

Structural bowel damage measurements collected by semi-automated approaches are comparable to those of experienced radiologists. Radiomic measures of CD will become an important new data source powering clinical decision-making, patient-phenotyping, and assisting radiologists in reporting objective measures of disease status.

How Do We Treat Inflammatory Bowel Diseases to Aim For Endoscopic Remission?

Crohn's disease and ulcerative colitis are heterogeneous conditions which may manifest with 1 or more of a constellation of abnormal symptoms, elevated biomarkers, and/or objective evidence of inflammation on endoscopic or cross-sectional evaluation. Whilst resolution of symptoms and restoration of quality of life is the primary goal for patients following a disease flare, there may be discordance between resolution of symptoms, biomarkers, and endoscopy. Increased emphasis is placed on the achievement of endoscopic remission, given it is associated with improved outcomes and reduction in hospitalization and surgeries. As the therapeutic armamentarium for inflammatory bowel disease does not achieve remission in all patients, there is greater emphasis on repetitive interval-based assessment of disease activity with sequential algorithmic treatment adjustments until endoscopic remission is achieved, in a so-called treat-to-target approach. We review the role of symptoms, biomarkers, imaging and endoscopy within treat-to-target algorithms and provide a practical guidance to their use in clinical practice.

Feasibility study using iodine quantification on dual-energy CT enterography to distinguish normal small bowel from active inflammatory Crohn's disease

BACKGROUND

Assessment of Crohn's disease (CD) activity is important to identify patients with active inflammation for therapy management. Quantitative analysis can provide objective measurement of disease presence.

PURPOSE

To evaluate the feasibility of quantitative analysis of contrast-enhanced dual-energy computed tomography (DECT) data in detection of small bowel inflammation in patients with CD with an emphasis on iodine quantification.

MATERIAL AND METHODS

DECT enterography was prospectively performed in 20 patients with active CD and in 20 healthy individuals, as the control group. Iodine overlay images were created. Wall thickness, attenuation, absolute iodine density, relative iodine density, and fat fraction were measured in the terminal ileum of all patients by two radiologists. Intraclass correlation coefficients were calculated to assess inter-rater agreement. Parameters were compared between patient groups using mixed model analysis. Receiver operating characteristic (ROC) analysis was performed.

RESULTS

Both absolute and relative iodine density were significantly higher in active disease than in normal small bowel (all P < 0.001). In contrast, measurement of fat fraction was not significantly different in affected terminal ileal loops compared to normal terminal ileum ( P = 0.075). ROC analysis demonstrated a similar excellent diagnostic accuracy of wall thickness, attenuation, and absolute and relative iodine density with area under the ROC curve (AUC) values in the range of 0.96 for attenuation to 1 for relative iodine density.

CONCLUSION

DECT with iodine quantification can be used in distinguishing normal small bowel from active inflammatory CD. Further research should investigate the value of iodine quantification in grading CD activity and in monitoring therapeutic response.

Differences in the imaging of Crohn's disease patients between North America and Europe: are we ready to bridge the divide?

The emphasis of treatment in Crohn's disease has evolved from a reactive model to "treat-to-target" approaches. Cross-sectional imaging has rapidly evolved in parallel, with a growing evidence base supporting its abilities for diagnosis, monitoring and prognostication. Whilst there are differences in emphasis between Europe and North America, particularly around the type of imaging modalities and patterns of multidisciplinary care, there is increasing convergence. This perspective piece provides an overview of the evolving role of cross-sectional imaging in Crohn's disease, discusses practice differences between North America and Europe and provides suggestions on areas for future collaboration and research priorities.

Inter-radiologist agreement using Society of Abdominal Radiology-American Gastroenterological Association (SAR-AGA) consensus nomenclature for reporting CT and MR enterography in children and young adults with small bowel Crohn disease

PURPOSE

To assess inter-radiologist agreement using the Society of Abdominal Radiology-American Gastroenterological Association (SAR-AGA) consensus recommendations for reporting CT/MR enterography exams in pediatric and young adult small bowel Crohn disease (CD).

METHODS

Institutional review board approval was obtained for this HIPAA-compliant retrospective investigation; the requirement for informed consent was waived. 25 CT and 25 MR enterography exams performed in children and young adults (age range: 6-23 years) between January 2015 and April 2017 with a distribution of ileal CD severity (phenotype) were identified: normal or chronic CD without active inflammation (40%), active inflammatory CD (20%), stricturing CD (20%), and penetrating CD (20%). Five fellowship-trained pediatric radiologists, blinded to one another, documented key imaging findings and standardized impressions based on SAR-AGA consensus recommendations. Inter-radiologist agreement was evaluated using Fleiss' multi-rater kappa statistic (κ) with 95% confidence intervals (CI).

RESULTS

Inter-radiologist agreement was moderate for all key imaging findings except presence of ulcerations (κ 0.37 [95% CI 0.28-0.46]) and sacculations (κ 0.31 [95% CI 0.23-0.40]). Agreement for standardized impressions was substantial for stricturing disease (κ 0.79 [95% CI 0.70-0.87]) and moderate for presence of inflammation (κ 0.49 [95% CI 0.44-0.56]) and penetrating disease (κ 0.58 [95% CI 0.49-0.67]). No significant difference in agreement was found between CT and MRI.

CONCLUSIONS

Agreement among five pediatric radiologists was moderate to substantial for SAR-AGA standardized impressions and fair to moderate for key imaging findings of pediatric and young adult CD.

AGA Clinical Practice Update on Functional Gastrointestinal Symptoms in Patients With Inflammatory Bowel Disease: Expert Review

DESCRIPTION

The purpose of this clinical practice update review is to describe key principles in the diagnosis and management of functional gastrointestinal (GI) symptoms in patients with inflammatory bowel disease (IBD).

METHODS

The evidence and best practices summarized in this manuscript are based on relevant scientific publications, systematic reviews, and expert opinion where applicable. Best practice advice 1: A stepwise approach to rule-out ongoing inflammatory activity should be followed in IBD patients with persistent GI symptoms (measurement of fecal calprotectin, endoscopy with biopsy, cross-sectional imaging). Best practice advice 2: In those patients with indeterminate fecal calprotectin levels and mild symptoms, clinicians may consider serial calprotectin monitoring to facilitate anticipatory management. Best practice advice 3: Anatomic abnormalities or structural complications should be considered in patients with obstructive symptoms including abdominal distention, pain, nausea and vomiting, obstipation or constipation. Best practice advice 4: Alternative pathophysiologic mechanisms should be considered and evaluated (small intestinal bacterial overgrowth, bile acid diarrhea, carbohydrate intolerance, chronic pancreatitis) based on predominant symptom patterns. Best practice advice 5: A low FODMAP diet may be offered for management of functional GI symptoms in IBD with careful attention to nutritional adequacy. Best practice advice 6: Psychological therapies (cognitive behavioural therapy, hypnotherapy, mindfulness therapy) should be considered in IBD patients with functional symptoms. Best practice advice 7: Osmotic and stimulant laxative should be offered to IBD patients with chronic constipation. Best practice advice 8: Hypomotility agents or bile-acid sequestrants may be used for chronic diarrhea in quiescent IBD. Best practice advice 9: Antispasmodics, neuropathic-directed agents, and anti-depressants should be used for functional pain in IBD while use of opiates should be avoided. Best practice advice 10: Probiotics may be considered for treatment of functional symptoms in IBD. Best practice advice 11: Pelvic floor therapy should be offered to IBD patients with evidence of an underlying defecatory disorder. Best practice advice 12: Until further evidence is available, fecal microbiota transplant should not be offered for treatment of functional GI symptoms in IBD. Best practice advice 13: Physical exercise should be encourage in IBD patients with functional GI symptoms. Best practice advice 14: Until further evidence is available, complementary and alternative therapies should not be routinely offered for functional symptoms in IBD. This Clinical Practice Update was produced by the AGA Institute.

Clinical Benefit of Capsule Endoscopy in Crohn's Disease: Impact on Patient Management and Prevalence of Proximal Small Bowel Involvement

BACKGROUND

Ileocolonoscopy and computed tomography (CT) or magnetic resonance (MR) enterography (CTE/MRE) are utilized to evaluate patients with small bowel (SB) Crohn's disease (CD). The purpose of our study was to estimate the impact of capsule endoscopy (CE) on patient management after clinical assessment, ileocolonoscopy, and CTE/MRE.

METHODS

We prospectively analyzed 50 adult CD patients without strictures at clinically indicated ileocolonoscopy and CTE/MRE exams. Providers completed pre- and post-CE clinical management questionnaires. Pre-CE questionnaire assessed likelihood of active SBCD and management plan using a 5-point level of confidence (LOC) scales. Post-CE questionnaire assessed alteration in management plans and contribution of CE findings to these changes. A change of ≥2 on LOC scale was considered clinically meaningful.

RESULTS

Of the 50 patients evaluated (60% females), median age was 38 years, median disease duration was 3 years, and median Crohn's Disease Activity Index (CDAI) score was 238 points. All CTE/MRE studies were negative for proximal disease. CE detected proximal disease in 14 patients (28%) with a median Lewis score of 215 points. CE findings altered management in 17 cases (34%). The most frequent provider-perceived benefits of CE were addition of new medication (29%) and exclusion of active SB mucosal disease (24%).

CONCLUSION

CE is a safe imaging modality that alters clinical management in patients with established SBCD by adding incremental information not available at ileocolonoscopy and cross-sectional enterography.

Clinically Significant Small Bowel Crohn's Disease Might Only be Detected by Capsule Endoscopy

BACKGROUND

In Crohn's disease (CD) a small bowel study-in addition to colonoscopy-is considered necessary for diagnosis/staging. In this study we re-examined the role of capsule endoscopy (CE), colonoscopy, imaging tests [magnetic resonance enterography/computed tomographic enterography (MRE/CTE)], and inflammatory markers [fecal lactoferrin and C-reactive protein (FL/CRP)] in CD patients who had undergone intestinal resection and in those who never had surgery.

METHODS

In this retrospective study 43 consecutive patients underwent CE because of staging/symptoms unexplained by colonoscopy/imaging. We compared colonoscopy, imaging, and FL/CRP with CE and evaluated the impact of the latter on clinical management and outcomes.

RESULTS

In patients who never had surgery imaging was negative with a positive CE in 8/15 (53%) of cases. Colonoscopy was insufficient for disease staging in 10/20 (50%) cases. CRP and FL were normal with a positive CE in 35% and 28% of cases, respectively. CE findings changed the management in 6/20 (30%) of cases, with 83% showing clinical/biochemical improvement after up to 15 months of follow-up. In postoperative patients CE was positive with negative imaging in 6/8 (75%) cases. Colonoscopy was insufficient for disease staging in 13/22 (59%) cases. CRP and FL were normal in 42% and 31.8% of patients with positive CE. In these patients CE findings changed the management in 12/23 (52%) cases with 83% of them showing clinical/biochemical improvement after up to 18 months of follow-up.

CONCLUSIONS

Omitting CE from diagnostic/staging algorithms in CD tends to underdiagnose clinically significant small bowel lesions, thus impacting on patients' management and outcomes. 10.1093/ibd/izy048_video1izy048.video15794820403001.

Small bowel imaging in Crohn's disease patients

Crohn’s disease (CD) is a lifelong, chronic inflammatory bowel disorder. The small bowel (SB) is involved to varying extents, and the clinical course may vary from an inflammatory type to a more complicated one with stricture, fistula, and abscess formation. Esophagogastroduodenoscopy and ileocolonoscopy with biopsies are the conventional endoscopic techniques that usually establish the diagnosis. On the other hand, CD may affect SB segments that cannot be reached through these procedures. Video capsule endoscopy and enteroscopy are additional endoscopic techniques that may allow further SB evaluation in such circumstances. Computed tomographic enterography, magnetic resonance enterography, and ultrasonography are radiologic techniques that serve as a crucial adjunct to endoscopic assessment. They enable the assessment of parts of the bowel that may be difficult to reach with conventional endoscopy; this allows for the detection of active inflammation, penetrating or stricturing disease, and the appreciation of extraintestinal complications. Both endoscopic and radiologic modalities play a role in establishing the diagnosis of CD, as well as determining the disease extent, activity and response to therapy. This review is intended to evaluate these modalities in terms of specificity, sensitivity, potential side-effects, and limiting factors. This should serve as a guide to the clinician for establishing the most appropriate and reliable test within a particular clinical context.

Consensus Recommendations for Evaluation, Interpretation, and Utilization of Computed Tomography and Magnetic Resonance Enterography in Patients With Small Bowel Crohn's Disease

Computed tomography and magnetic resonance enterography have become routine small bowel imaging tests to evaluate patients with established or suspected Crohn's disease, but the interpretation and use of these imaging modalities can vary widely. A shared understanding of imaging findings, nomenclature, and utilization will improve the utility of these imaging techniques to guide treatment options, as well as assess for treatment response and complications. Representatives from the Society of Abdominal Radiology Crohn's Disease-Focused Panel, the Society of Pediatric Radiology, the American Gastroenterological Association, and other experts, systematically evaluated evidence for imaging findings associated with small bowel Crohn's disease enteric inflammation and established recommendations for the evaluation, interpretation, and use of computed tomography and magnetic resonance enterography in small bowel Crohn's disease. This work makes recommendations for imaging findings that indicate small bowel Crohn's disease, how inflammatory small bowel Crohn's disease and its complications should be described, elucidates potential extra-enteric findings that may be seen at imaging, and recommends that cross-sectional enterography should be performed at diagnosis of Crohn's disease and considered for small bowel Crohn's disease monitoring paradigms. A useful morphologic construct describing how imaging findings evolve with disease progression and response is described, and standard impressions for radiologic reports that convey meaningful information to gastroenterologists and surgeons are presented.

Accuracy of Computed Tomographic Enterography for Obscure Gastrointestinal Bleeding: A Diagnostic Meta-analysis

RATIONALE AND OBJECTIVES

Obscure gastrointestinal bleeding (OGIB) is the bleeding from the gastrointestinal tract without definite source that persists and recurs after a negative endoscopic evaluation. The study aimed to systematically evaluate the diagnostic accuracy of computed tomography enterography on OGIB detection by meta-analysis.

MATERIALS AND METHODS

Studies were searched in relevant databases. With predefined inclusion criteria, eligible studies were included, followed by quality assessment using the Quality Assessment of Diagnostic Accuracy Studies scoring system. The Meta-DiSc software was used to implement the meta-analysis, and sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio with their 95% confidence intervals (CIs) were used as the effect size. Publication bias was determined by Egger test.

RESULTS

A set of nine studies was included in this meta-analysis, having a relatively high quality. Under the random effects model, the pooled sensitivity and specificity were 0.724 (95% CI: 0.651-0.789) and 0.752 (95% CI: 0.691-0.807), respectively. Under the fixed effects model, the pooled positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 2.949 (95% CI: 2.259-3.850), 0.393 (95% CI: 0.310-0.497), and 9.452 (95% CI: 5.693-15.692), respectively. The area under curve of the summary receiver operating characteristic curve was 0.7916 (95% CI: 0.723-0.860). No obvious publication bias was detected (t = 1.62, P = .181).

CONCLUSIONS

Computed tomography enterography might be used as a complementary to video capsule endoscopy instead of an alternative for the detection of OGIB.

Consensus Recommendations for Evaluation, Interpretation, and Utilization of Computed Tomography and Magnetic Resonance Enterography in Patients With Small Bowel Crohn's Disease

Computed tomography and magnetic resonance enterography have become routine small bowel imaging tests to evaluate patients with established or suspected Crohn's disease, but the interpretation and use of these imaging modalities can vary widely. A shared understanding of imaging findings, nomenclature, and utilization will improve the utility of these imaging techniques to guide treatment options, as well as assess for treatment response and complications. Representatives from the Society of Abdominal Radiology Crohn's Disease-Focused Panel, the Society of Pediatric Radiology, the American Gastroenterological Association, and other experts, systematically evaluated evidence for imaging findings associated with small bowel Crohn's disease enteric inflammation and established recommendations for the evaluation, interpretation, and use of computed tomography and magnetic resonance enterography in small bowel Crohn's disease. This work makes recommendations for imaging findings that indicate small bowel Crohn's disease, how inflammatory small bowel Crohn's disease and its complications should be described, elucidates potential extra-enteric findings that may be seen at imaging, and recommends that cross-sectional enterography should be performed at diagnosis of Crohn's disease and considered for small bowel Crohn's disease monitoring paradigms. A useful morphologic construct describing how imaging findings evolve with disease progression and response is described, and standard impressions for radiologic reports that convey meaningful information to gastroenterologists and surgeons are presented. ^©2018, RSNA, AGA Institute, and Society of Abdominal Radiology This article is being published jointly in Radiology and Gastroenterology.

Utility of Emergency Department Use of Abdominal Pelvic Computed Tomography in the Management of Crohn's Disease

GOAL

The primary aim of this study was to determine predictors of clinically significant computed tomography (CT) scans, paying particular attention to findings of previous CT scans.

BACKGROUND

Use of CT to assess patients with Crohn's disease (CD) in the Emergency Department (ED) is both costly and exposes patients to high levels of ionizing radiation while not clearly improving outcomes.

STUDY

Patients with CD who underwent CT scan in the Emergency Department from 2008 to 2011 at a tertiary referral center were assessed for clinically significant findings. A multivariable generalized estimating equation model with logit link and exchangeable working correlation structure was constructed to assess for independent predictors of CT scans with clinically significant findings.

RESULTS

A total of 118 patients with CD underwent 194 CT scans. Ninety-two of 194 (47%) CT scans demonstrated clinically significant findings. Predictors of clinically significant CT scans included ileal disease involvement [odds ratios (OR) 3.47, P=0.01] and white blood cell count >12 (OR 2.1, P=0.03). Most notably, patients with a CT scan without clinically significant findings performed in the preceding month were significantly less likely to have a clinically significant CT scan (OR 0.23, P=0.005).

CONCLUSIONS

Patients with CD who had a CT scan without significant findings the month prior are unlikely to have clinically significant CT findings. Ileal disease and an elevated white blood cell are predictive of clinically significant CT scans.

Endoscopic and Radiographic Assessment of Crohn's Disease

Crohn's disease is a chronic inflammatory disorder that can progress to obstructive and penetrating complications. Although clinical symptoms are an important component of therapy, they correlate poorly with objective measures of inflammation. The treatment targets have evolved from clinical improvement only to the addition of more objective measures, such as endoscopic mucosal healing and radiologic response, which have been associated with favorable long-term outcomes, including reduced hospitalizations, surgeries, and need for corticosteroids. There are multiple endoscopic and radiologic scoring systems that can aid in quantifying disease activity and response to therapy. These modalities and scoring tools are discussed in this article.

Crohn's disease diagnosis, treatment approach, and management paradigm: what the radiologist needs to know

Crohn's disease is one of the major subtypes of idiopathic inflammatory bowel disease and is characterized by chronic transmural intestinal inflammation of the gastrointestinal tract anywhere from mouth to the anus, with a predilection for the small bowel. Cross-sectional imaging with computed tomography and magnetic resonance enterography plays a key role in confirming diagnosis, identifying and managing complications, assessing disease severity, and identifying response to medical therapy. This review will focus on the role of radiologists in the diagnosis and assessment of Crohn's disease. Additionally, a review of current medical therapy approaches, available medications, and side effects will be discussed. The review will also highlight key complications of medical therapy and associated diseases that should be evaluated by the radiologist with cross-sectional imaging.

Small Bowel Imaging: Computed Tomography Enterography, Magnetic Resonance Enterography, Angiography, and Nuclear Medicine

Radiology examinations play a major role in the diagnosis, management, and surveillance of small bowel diseases and are complementary to endoscopic techniques. Computed tomography enterography and magnetic resonance enterography are the cross-sectional imaging studies of choice for many small bowel diseases. Angiography still plays an important role for catheter-directed therapies. With the emergence of hybrid imaging techniques, radionuclide imaging has shown promise for the evaluation of small bowel bleeding and Crohn disease and may play a larger role in the future. This article reviews recent advances in technology, diagnosis, and therapeutic options for selected small bowel disorders.

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

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

LEVEL OF EVIDENCE

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

Computed Tomography and Magnetic Resonance Enterography in Crohn's Disease: Assessment of Radiologic Criteria and Endpoints for Clinical Practice and Trials

Early recognition of Crohn's disease with initiation of disease-modifying therapy has emerged as a prominent inflammatory bowel disease management strategy. Clinical practice and trials have often focused on patient symptoms, and more recently, serologic tests, stool inflammatory markers, and/or endoscopic inflammatory features for study entry criteria, treatment targets, disease activity monitoring, and to assess therapeutic response. Unfortunately, patient symptoms do not correlate well with biological disease activity, and endoscopy potentially misses or underestimates disease extent and severity in small bowel Crohn's disease. Computed tomography enterography and magnetic resonance enterography (MRE) are potential tools to identify and quantify transmural structural damage and disease activity in the small bowel. In this review, we discuss the role of computed tomography enterography and MRE in disease management algorithms in clinical practice. We also compare the currently developed MRE-based scoring systems, their strengths and pitfalls, as well as the role for MRE in clinical trials for Crohn's disease.

Endoscopy and cross-sectional imaging for assessing Crohn׳s disease activity

Crohn's disease (CD) is principally characterized by chronic and recurrent inflammation of the gastrointestinal tract, most commonly found in the ileo-colonic region. The chronicity and severity of intestinal inflammation together contribute to progressive, cumulative, deep, transmural intestinal damage, including stricturing, obstruction, abscesses, and fistulae. Both intestinal inflammation and its chronic complications result in a range of symptoms subsequently leading to patient presentations with diarrhea, abdominal pain, and anemia related to intestinal blood loss. Measuring disease activity and severity are essential for decision of treatment intensity early in the disease course and longitudinal monitoring of therapeutic efficacy. This review will summarize the transition from subjective symptoms driving disease activity indices, into increasingly objective and quantitative measures of intestinal injury by direct mucosal assessment (endoscopy), cross-sectional imaging, and surrogate biomarkers. Specific commentary on intestinal stricture and perianal fistula assessment and management are presented in accompanying sections of this series.

Radiological Response Is Associated With Better Long-Term Outcomes and Is a Potential Treatment Target in Patients With Small Bowel Crohn's Disease

OBJECTIVES

Crohn's disease (CD) management targets mucosal healing on ileocolonoscopy as a treatment goal. We hypothesized that radiologic response is also associated with better long-term outcomes.

METHODS

Small bowel CD patients between 1 January 2002 and 31 October 2014 were identified. All patients had pre-therapy computed tomography enterography (CTE)/magnetic resonance enterography (MRE) with follow-up CTE or MRE after 6 months, or 2 CTE/MREs≥6 months apart while on maintenance therapy. Radiologists characterized inflammation in up to five small bowel lesions per patient. At second CTE/MRE, complete responders had all improved lesions, non-responders had worsening or new lesions, and partial responders had other scenarios. CD-related outcomes of corticosteroid usage, hospitalization, and surgery were assessed using Kaplan-Meier survival analysis and multivariable Cox models.

RESULTS

CD patients (n=150), with a median disease duration of 9 years, had 223 inflamed small bowel segments (76 with strictures and 62 with penetrating, non-perianal disease), 49% having ileal distribution. Fifty-five patients (37%) were complete radiologic responders, 39 partial (26%), and 56 non-responders (37%). In multivariable Cox models, complete and partial response decreased risk for steroid usage by over 50% (hazard ratio (HR)s: 0.37 (95% confidence interval (CI), 0.21-0.64); 0.45 (95% CI, 0.26-0.79)), and complete response decreased the risk of subsequent hospitalizations and surgery by over two-thirds (HRs: HR, 0.28 (95% CI, 0.15-0.50); HR, 0.34 (95% CI, 0.18-0.63)).

CONCLUSIONS

Radiological response to medical therapy is associated with significant reductions in long-term risk of hospitalization, surgery, or corticosteroid usage among small bowel CD patients. These findings suggest the significance of radiological response as a treatment target.

Observer performance for adaptive, image-based denoising and filtered back projection compared to scanner-based iterative reconstruction for lower dose CT enterography

PURPOSE

The purpose of this study was to compare observer performance for detection of intestinal inflammation for low-dose CT enterography (LD-CTE) using scanner-based iterative reconstruction (IR) vs. vendor-independent, adaptive image-based noise reduction (ANLM) or filtered back projection (FBP).

METHODS

Sixty-two LD-CTE exams were performed. LD-CTE images were reconstructed using IR, ANLM, and FBP. Three readers, blinded to image type, marked intestinal inflammation directly on patient images using a specialized workstation over three sessions, interpreting one image type/patient/session. Reference standard was created by a gastroenterologist and radiologist, who reviewed all available data including dismissal Gastroenterology records, and who marked all inflamed bowel segments on the same workstation. Reader and reference localizations were then compared. Non-inferiority was tested using Jackknife free-response ROC (JAFROC) figures of merit (FOM) for ANLM and FBP compared to IR. Patient-level analyses for the presence or absence of inflammation were also conducted.

RESULTS

There were 46 inflamed bowel segments in 24/62 patients (CTDIvol interquartile range 6.9-10.1 mGy). JAFROC FOM for ANLM and FBP were 0.84 (95% CI 0.75-0.92) and 0.84 (95% CI 0.75-0.92), and were statistically non-inferior to IR (FOM 0.84; 95% CI 0.76-0.93). Patient-level pooled confidence intervals for sensitivity widely overlapped, as did specificities. Image quality was rated as better with IR and AMLM compared to FBP (p < 0.0001), with no difference in reading times (p = 0.89).

CONCLUSIONS

Vendor-independent adaptive image-based noise reduction and FBP provided observer performance that was non-inferior to scanner-based IR methods. Adaptive image-based noise reduction maintained or improved upon image quality ratings compared to FBP when performing CTE at lower dose levels.

CT enterography: technical and interpretive pitfalls

CT enterography is a first-line test at many institutions to investigate potential small bowel disorders. While numerous articles have focused on the ability of CT enterography to diagnose and stage Crohn's disease, small bowel neoplasia, and malabsorptive or vascular disorders, this article reviews CT enterography limitations, technical and interpretive pitfalls, image review tactics, and complementary radiologic and endoscopic examinations to improve diagnostic accuracy. CT enterography limitations include its inability to demonstrate isolated mucosal abnormalities such as aphthous ulcers and its use of ionizing radiation. The most common technical pitfall of CT enterography is inadequate small bowel distention resulting from inadequate ingestion, gastric retention, or rapid small bowel transit of a large volume of neutral enteric contrast material. Additionally, segments of jejunum are frequently collapsed. Interpretive pitfalls commonly result from peristaltic contractions, transient intussusception and opaque intraluminal debris. Opaque debris is especially problematic during multiphasic CT enterography performed to identify potential small bowel sources of obscure gastrointestinal bleeding. False-negative examinations may result from inadequate radiation dose. Examinations complementary to CT enterography include small bowel follow through, enteroclysis, CT enteroclysis, MR enterography, MR enteroclysis, capsule endoscopy, and balloon-assisted endoscopy. Properly performed and accurately interpreted CT enterography contributes to the diagnosis and management of small bowel disease by itself and as a complement to other radiologic and optical small bowel imaging examinations.

Impact of Intestinal Ultrasound on Classification and Management of Crohn's Disease Patients with Inconclusive Colonoscopy

Background and Aims. We aim to evaluate the benefit of ultrasound in the assessment of Crohn's disease and to demonstrate its potential contribution to disease management. Methods. We conduct a retrospective review of adult patients with Crohn's disease examined with sonography and colonoscopy within 30 days. Study patients were identified in whom colonoscopy did not access a pathological segment, detected and evaluated by ultrasonography. Changes in management were predominantly attributed to ultrasound in those cases where the diseased segment was not assessed on endoscopy. Results. From 115 patients with temporally related ileocolonoscopy and ultrasound, 41 had disease fully assessed on ultrasound only, with complications in 26/41. Twenty-nine of 41 had mild or no endoscopic inflammation with moderate or severe disease on ultrasound at the same segment or at a segment proximal to the reach of the endoscope. Changes in management were significantly attributed to ultrasound in 22 of these 29 patients. Conclusion. The benefit of cross-sectional imaging is invaluable for the comprehensive assessment of bowel not shown on ileocolonoscopy. Ultrasound may make a significant contribution to correct classification of disease extent and severity of Crohn's disease. Prospective studies are needed to further understand the contribution of US in patient management.

Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE): Determining Therapeutic Goals for Treat-to-Target

OBJECTIVES

The Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE) program was initiated by the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD). It examined potential treatment targets for inflammatory bowel disease (IBD) to be used for a "treat-to-target" clinical management strategy using an evidence-based expert consensus process.

METHODS

A Steering Committee of 28 IBD specialists developed recommendations based on a systematic literature review and expert opinion. Consensus was gained if ≥75% of participants scored the recommendation as 7-10 on a 10-point rating scale (where 10=agree completely).

RESULTS

The group agreed upon 12 recommendations for ulcerative colitis (UC) and Crohn's disease (CD). The agreed target for UC was clinical/patient-reported outcome (PRO) remission (defined as resolution of rectal bleeding and diarrhea/altered bowel habit) and endoscopic remission (defined as a Mayo endoscopic subscore of 0-1). Histological remission was considered as an adjunctive goal. Clinical/PRO remission was also agreed upon as a target for CD and defined as resolution of abdominal pain and diarrhea/altered bowel habit; and endoscopic remission, defined as resolution of ulceration at ileocolonoscopy, or resolution of findings of inflammation on cross-sectional imaging in patients who cannot be adequately assessed with ileocolonoscopy. Biomarker remission (normal C-reactive protein (CRP) and calprotectin) was considered as an adjunctive target.

CONCLUSIONS

Evidence- and consensus-based recommendations for selecting the goals for treat-to-target strategies in patients with IBD are made available. Prospective studies are needed to determine how these targets will change disease course and patients' quality of life.

Diagnostic Performance and Dose Comparison of Filtered Back Projection and Adaptive Iterative Dose Reduction Three-dimensional CT Enterography in Children and Young Adults

PURPOSE

To investigate diagnostic performance and radiation dose with the use of computed tomographic (CT) enterography in children and young adults and to compare reconstruction with filtered back projection (FBP) to that with adaptive iterative dose reduction (AIDR) with three-dimensional (3D) processing.

MATERIALS AND METHODS

This retrospective investigation was HIPAA compliant and approved by the institutional review board. Informed consent was waived. CT enterographic examinations performed between October 2008 and June 2009 with FBP and between August 2012 and April 2014 with AIDR 3D in patients who had received histologic evaluation within 45 days of imaging were included. Two reviewers retrospectively and independently evaluated the studies for findings of active inflammation, and diagnostic performance and interreader reliability were assessed. The reference standard was histologic findings. Objective and subjective image quality also was assessed. The size-specific dose estimate was compared between the two groups. Two-sample t tests or analysis of variance tests were performed to assess for differences in diagnostic accuracy, image quality, and radiation dose between the FBP and AIDR 3D examinations.

RESULTS

Fifty patients were included in the FBP group (mean age, 14.1 years; range, 8-21 years) and 68 patients were in the AIDR 3D group (mean age, 13.2 years; range, 2-29 years). Sensitivity and specificity for detection of active inflammation were 96% (26 of 27) and 96% (22 of 23), respectively, for the FBP group and 90% (45 of 50) and 89% (16 of 18), respectively, for the AIDR 3D group. Dichotomous interreader reliability (κ) for the entire group was 0.86. The mean size-specific dose estimate for all weights was significantly lower for the AIDR 3D group (6.1 mGy ± 2.1) than that for the FBP group (16.7 mGy ± 5.2; P < .0001). No significant difference was found in objective image noise for soft-tissue structures (P = .2-.8).

CONCLUSION

CT enterography is highly accurate for detection of active inflammation in pediatric patients and has excellent interreader reliability. Reduced-dose CT enterography with AIDR 3D allowed substantial dose reduction compared with that used with FBP CT enterographic examinations, while maintaining a high diagnostic performance.

Accuracy of CT enterography and magnetic resonance enterography imaging to detect lesions preoperatively in patients undergoing surgery for Crohn's disease

BACKGROUND

CT enterography and magnetic resonance enterography have emerged as first-line imaging technologies for the evaluation of the gastrointestinal tract in Crohn's disease.

OBJECTIVE

The purpose of this work was to evaluate the accuracy of these imaging modalities to identify Crohn's disease lesions preoperatively.

DESIGN

This was a retrospective chart review.

SETTINGS

The study was conducted at a single institution.

PATIENTS

Seventy-six patients with Crohn's disease with preoperative CT enterography and/or magnetic resonance enterography were included in the study.

MAIN OUTCOME MEASURES

The number of stenoses, fistulas, and abscesses on CT enterography and/or magnetic resonance enterography before surgery were compared with operative findings.

RESULTS

Forty patients (53%) were women, 46 (60%) underwent surgery for recurrent Crohn's disease, and 46 (57%) had previous abdominal surgery. Thirty-six (47%) had a preoperative CT enterography and 43 (57%) had a preoperative magnetic resonance enterography. CT enterography sensitivity was 75% for stenosis and 50% for fistula. MRE sensitivity was 68% for stenosis and 60% for fistula. The negative predictive values of CT enterography and magnetic resonance enterography for stenosis were very low (54% and 65%) and were 85% and 81% for fistula. CT enterography had 76% accuracy for stenosis and 79% for fistula; magnetic resonance enterography had 78% accuracy for stenosis and 85% for fistula. Both were accurate for abscess. False-negative rates for CT enterography were 50% for fistula and 25% for stenosis. False-negative rates for magnetic resonance enterography were 40% for fistula and 32% for stenosis. Unexpected intraoperative findings led to modification of the planned surgical procedure in 20 patients (26%).

LIMITATIONS

This study was limited by its small sample size, its retrospective nature, and that some studies were performed at outside institutions.

CONCLUSIONS

CT enterography and magnetic resonance enterography in patients with Crohn's disease were accurate for the identification of abscesses but not for fistulas or stenoses. Surgeons should search for additional lesions intraoperatively. Patients should be appropriately counseled regarding the need for unexpected interventions (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A162).

MR imaging of the small bowel in Crohn disease

MR enterography has an established role in evaluating patients with Crohn disease providing essential complementary information to clinical assessment, and as an indispensible adjunct to clinical tools such as colonoscopy. MR enterography examinations can establish the diagnosis of Crohn disease, evaluate disease activity and complications, and assess treatment response, thus providing support for clinical decision-making. Currently, MR imaging findings are highly predictive of tissue inflammation and can be used clinically to guide clinical care.

Capsule endoscopy is superior to small-bowel follow-through and equivalent to ileocolonoscopy in suspected Crohn's disease

BACKGROUND & AIMS

Evaluation of the small intestine for inflammation has traditionally relied on small-bowel follow-through (SBFT), but multiple studies have demonstrated its low diagnostic accuracy. Capsule endoscopy (CE) transmits high-quality images of the small intestinal mucosa; it can be used to visualize the entire length of the small bowel and much of the mucosa. We compared the diagnostic yields of CE vs SBFT in a prospective study of patients with suspected small-bowel Crohn's disease.

METHODS

Eighty patients with signs and/or symptoms of small-bowel Crohn's disease (age, 10-65 years) underwent CE, followed by SBFT and ileocolonoscopy. Readers were blinded to other test results. The primary outcome was the diagnostic yield for inflammatory lesions found with CE before ileocolonoscopy compared with SBFT and ileocolonoscopy. A secondary outcome was the incremental diagnostic yield of CE compared with ileocolonoscopy and CE compared with SBFT.

RESULTS

The combination of CE and ileocolonoscopy detected 107 of 110 inflammatory lesions (97.3%), whereas the combination of SBFT and ileocolonoscopy detected only 63 lesions (57.3%) (P < .001). The diagnostic yield of CE compared with ileocolonoscopy was not different (P = .09). The diagnostic yield was higher for CE than for SBFT (P < .001). Of the 80 patients with suspected Crohn's disease, 25 (31.3%) had the diagnosis confirmed. Eleven were diagnosed by CE findings alone and 5 by ileocolonoscopy findings alone. In the remaining 9 patients, diagnostic findings were identified by at least 2 of the 3 modalities. No diagnoses were made on the basis of SBFT findings alone.

CONCLUSIONS

CE was better than SBFT and equivalent to ileocolonoscopy in detecting small-bowel inflammation. Although ileocolonoscopy remains the initial diagnostic test of choice, CE is safe and can establish the diagnosis of Crohn's disease in patients when ileocolonoscopy results are negative or the terminal ileum cannot be evaluated. ClinicalTrials.gov Number: NCT00487396.

Increased prevalence of luminal narrowing and stricturing identified by enterography in pediatric Crohn's disease patients with elevated granulocyte-macrophage colony stimulating factor autoantibodies

BACKGROUND

Crohn's disease (CD) patients with elevated granulocyte-macrophage colony-stimulating factor autoantibodies (GM-CSF Ab) are more likely to develop stricturing behavior requiring surgery. Computed tomography or magnetic resonance enterography (CTE or MRE) may detect luminal narrowing (LN) before stricture development. The objective of this study was to determine whether CD patients with elevated GM-CSF Ab (≥1.6 μg/mL) have a higher prevalence of LN and stricturing on CTE or MRE.

METHODS

A single-center, cross-sectional study of 153 pediatric patients with CD and control subjects undergoing diagnostic CTE or MRE. Examinations were evaluated for disease activity using a novel scoring system and for the presence of LN, stricture, intra-abdominal abscess, or fistulae. Dichotomous outcomes were compared with respect to antibody status (high or low) using Fisher's exact test and logistic regression, whereas continuous outcomes were evaluated using unpaired t test.

RESULTS

GM-CSF Ab were elevated in CD patients (n = 114) with a median (interquartile range) GM-CSF Ab level of 2.3 μg/mL (0.5-6.6 μg/mL) compared with 0.6 μg/mL (0.3-1.3 μg/mL) in healthy and disease control subjects (n = 39) (P = 0.001). Ileal disease location was more common in CD patients with high GM-CSF Ab (P < 0.001). LN increased from 39% in CD patients with low GM-CSF Ab to 71% in those with high levels (P = 0.004) and remained significantly associated with high GM-CSF Ab in a multivariate logistic model, which included age, gender, small bowel location, and duration of disease. Stricturing prevalence on CTE or MRE examination increased from 4% in CD patients with low GM-CSF Ab to 19% in those with high GM-CSF Ab (P = 0.03).

CONCLUSIONS

Pediatric CD patients with high GM-CSF Ab levels have a higher prevalence of LN on CTE or MRE. Further study will be needed to determine whether medical therapy will reduce progression to stricturing behavior in these patients.