Outcomes of computed tomography and magnetic resonance enterography in clinical practice of inflammatory bowel disease

Refining nanoprobes for monitoring of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a gastrointestinal immune disease that requires clear diagnosis, timely treatment, and lifelong monitoring. The diagnosis and monitoring methods of IBD mainly include endoscopy, imaging examination, and laboratory examination, which are constantly developed to achieve early definite diagnosis and accurate monitoring. In recent years, with the development of nanotechnology, the diagnosis and monitoring methods of IBD have been remarkably enriched. Nanomaterials, characterized by their minuscule dimensions that can be tailored, along with their distinctive optical, magnetic, and biodistribution properties, have emerged as valuable contrast agents for imaging and targeted agents for endoscopy. Through both active and passive targeting mechanisms, nanoparticles accumulate at the site of inflammation, thereby enhancing IBD detection. This review comprehensively outlines the existing IBD detection techniques, expounds upon the utilization of nanoparticles in IBD detection and diagnosis, and offers insights into the future potential of in vitro diagnostics. STATEMENT OF SIGNIFICANCE: Due to their small size and unique physical and chemical properties, nanomaterials are widely used in the biological and medical fields. In the area of oncology and inflammatory disease, an increasing number of nanomaterials are being developed for diagnostics and drug delivery. Here, we focus on inflammatory bowel disease, an autoimmune inflammatory disease that requires early diagnosis and lifelong monitoring. Nanomaterials can be used as contrast agents to visualize areas of inflammation by actively or passively targeting them through the intestinal mucosal epithelium where gaps exist due to inflammation stimulation. In this article, we summarize the utilization of nanoparticles in inflammatory bowel disease detection and diagnosis, and offers insights into the future potential of in vitro diagnostics.

Simplified Magnetic Resonance Index of Activity Is Useful for Terminal Ileal but not Colonic Disease in Pediatric Crohn Disease

BACKGROUND

Ileocolonoscopy (IC) detects mucosal inflammation and magnetic resonance enterography (MRE) detects transmural inflammation in Crohn disease (CD). We aimed to evaluate the relationship between the simplified magnetic resonance index of activity (MARIAs) and measures of inflammation by IC in children with newly diagnosed CD.

METHODS

Retrospective review of 140 patients 6-18 years of age with CD who had baseline IC and MRE within 5 weeks of diagnosis. MARIAs was calculated for each intestinal segment (terminal ileum [TI], ascending colon, transverse colon, descending colon, sigmoid colon, rectum), defined as (1 × thickness > 3 mm) + (1 × edema) + (1 × fat stranding) + (2 × ulcers). Sensitivity and specificity were derived using receiver operating characteristic (ROC) curves to compare MARIAs to IC findings.

RESULTS

Using IC as the reference standard, the cutoff MARIAs ≥1 identified TI segments with active inflammation with 84% sensitivity, 73% specificity, 85% positive predictive value (PPV), 70% negative predictive value (NPV), and area under the curve (AUC) 0.782 (95% confidence interval [CI] 0.689-0.876). The cutoff MARIAs ≥2 identified TI segments with severe lesions with 87% sensitivity, 76% specificity, 87% PPV, 76% NPV, and AUC 0.814 (95% CI 0.712-0.916). There was poor sensitivity for all colonic segments.

CONCLUSION

The MARIAs is feasible and accurate in reflecting disease activity in the TI, but not in the colon, in children with newly diagnosed CD. Although the MARIAs may be useful for monitoring TI disease activity over time, full assessment continues to require both IC and MRE.

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

BACKGROUND

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

OBJECTIVE

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

DESIGN

Prospective multicentre cohort study.

SETTING

Eight NHS hospitals.

PARTICIPANTS

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

INTERVENTIONS

Magnetic resonance enterography and ultrasonography.

MAIN OUTCOME MEASURES

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

RESULTS

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

LIMITATIONS

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

CONCLUSIONS

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

TRIAL REGISTRATION

Current Controlled Trials ISRCTN03982913.

FUNDING

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

CT Enterography score: a potential predictor for severity assessment of active ulcerative colitis

BACKGROUND

Evaluate the possibility of CT enterography (CTE) score system as a predictor in assessing active ulcerative colitis (UC) severity.

METHODS

Forty-six patients with active UC with CTE and colonoscopy were enrolled. Based on modified Mayo score, patients were divided into three groups: mild (n = 10), moderate (n = 17) and severe (n = 19). A cumulative CTE score was calculated in each patient and its correlation with modified Mayo score was analyzed. The optimal cutoff values of CTE score were determined by receiver operating characteristic (ROC) curves analysis.

RESULTS

Significant between-group differences were observed in CTE spectrums of mucosal bubbles, mural stratification, loss of haustration, enlarged mesenteric lymph nodes and engorged mesenteric vessels (P < 0.05). The cumulative CTE scores were significant difference between three groups (CTE score:4.9 ± 2.3, 7.6 ± 2.6, and 10.9 ± 2.0, respectively, P < 0.01). The cumulative CTE score showed a positive correlation with modified Mayo score (r = 0.835, P < 0.05). The optimal cut-off value for CTE score predicting moderate and severe UC was 9.5 (area under the curve [AUC]:0.847, sensitivity:78.9%, specificity:82.4%).

CONCLUSION

Disease severity assessment by CTE score demonstrates strong positive correlation with severity established modified Mayo score. CTE score system maybe a potential predictor for active UC severity assessment.

An expert consensus to standardise definitions, diagnosis and treatment targets for anti-fibrotic stricture therapies in Crohn's disease

BACKGROUND

Fibrotic stricture is a common complication of Crohn's disease (CD) affecting approximately half of all patients. No specific anti-fibrotic therapies are available; however, several therapies are currently under evaluation. Drug development for the indication of stricturing CD is hampered by a lack of standardised definitions, diagnostic modalities, clinical trial eligibility criteria, endpoints and treatment targets in stricturing CD.

AIM

To standardise definitions, diagnosis and treatment targets for anti-fibrotic stricture therapies in Chron's disease.

METHODS

An interdisciplinary expert panel consisting of 15 gastroenterologists and radiologists was assembled. Using modified RAND/University of California Los Angeles appropriateness methodology, 109 candidate items derived from systematic review and expert opinion focusing on small intestinal strictures were anonymously rated as inappropriate, uncertain or appropriate. Survey results were discussed as a group before a second and third round of voting.

RESULTS

Fibrotic strictures are defined by the combination of luminal narrowing, wall thickening and pre-stenotic dilation. Definitions of anastomotic (at site of prior intestinal resection with anastomosis) and naïve small bowel strictures were similar; however, there was uncertainty regarding wall thickness in anastomotic strictures. Magnetic resonance imaging is considered the optimal technique to define fibrotic strictures and assess response to therapy. Symptomatic strictures are defined by abdominal distension, cramping, dietary restrictions, nausea, vomiting, abdominal pain and post-prandial abdominal pain. Need for intervention (endoscopic balloon dilation or surgery) within 24-48 weeks is considered the appropriate endpoint in pharmacological trials.

CONCLUSIONS

Consensus criteria for diagnosis and response to therapy in stricturing Crohn's disease should inform both clinical practice and trial design.

A Simple Ultrasound Score for the Accurate Detection of Inflammatory Activity in Crohn's Disease

BACKGROUND

Ultrasound is accurate in the detection of Crohn's disease. Our aim was to identify ultrasound parameters contributing to inflammatory disease activity, develop a simple score, and validate this score prospectively.

METHODS

This study comprised 2 single-center investigations. The first was a retrospective study on a population that had received colonoscopies (as a gold-standard diagnostic) within 60 days of ultrasound. The second was a prospective study on 2 populations: patients requiring induction with adalimumab and patients on adalimumab maintenance therapy. Ultrasound and endoscopy were preformed within 14 days in both prospective groups. The endoscopy results were graded with the Simple Endoscopic Score and the Rutgeerts score and compared with 5 ultrasound parameters. We used a proportional odds model to determine which ultrasound parameters correlated significantly with the endoscopy results. We then developed a predictive ultrasound score for disease activity, plotted the receiver operating characteristic curves, and undertook prospective validation of the score.

RESULTS

We evaluated 160 patients retrospectively to compare ultrasound and colonoscopy. Two of 5 parameters were found to correlate significantly with disease activity: bowel wall thickness (P = <0.0001) and color Doppler signal (P = 0.0292). We developed a score that uses weighted variables. The area under the corresponding receiver operating characteristic curve was 0.8658.

CONCLUSIONS

A simple ultrasonographic score that accurately identifies Crohn's disease activity has been developed and validated. Ultrasound may be a surrogate for endoscopy to guide disease management, but future studies should be conducted to establish interrater variability.

Accuracy of Diffusion-weighted Magnetic Resonance Colonography in Assessing Mucosal Healing and the Treatment Response in Patients with Ulcerative Colitis

BACKGROUND AND AIMS

Using sigmoidoscopy as the gold standard, we assessed the accuracy, and the responsiveness to change, of diffusion-weighted magnetic resonance colonography in ulcerative colitis, using the Nancy score.

METHODS

A total of 29 ulcerative colitis patients, having undergone at least two diffusion-weighted magnetic resonance colonographies, were included. Disease activity was evaluated using the Mayo endoscopic subscore and the Nancy score. We determined the accuracy of the Nancy score in the diagnosis of mucosal healing. We also assessed its responsiveness to change in 17 patients with a Mayo endoscopic subscore of 2 or 3 at treatment initiation.

RESULTS

A total Nancy score < 7 had a sensitivity of 0.75 and a specificity of 0.67 (area under the curve: 0.72; 95% confidence interval: [0.56-0.88]; p = 0.0063) in the diagnosis of mucosal healing. The total Nancy score was sensitive to change in ulcerative colitis [Guyatt's responsiveness index: 1.8; standardised effect size ratio: 1.36]. The Nancy score was reliable [intra-class correlation coefficient: 0.63; p = 0.01]. The mean Mayo endoscopic subscore and the mean Nancy score both fell significantly in patients who achieved mucosal healing (mean ± standard deviation [SD] Mayo endoscopic subscore: 2.4 ± 0.55 at baseline and 0.6 ± 0.55 at reassessment, p = 0.02; mean Nancy score: 18.2 ± 9.1 at baseline and 3 ± 1.6 at reassessment, p = 0.006). No significant changes in Nancy score were observed in active patients at reassessment.

CONCLUSIONS

The Nancy score is a highly responsive, reliable tool for assessing treatment response in patients with ulcerative colitis. The Nancy score accurately detects mucosal healing.

Approach to the Patient with Mild Crohn's Disease: a 2016 Update

Mild Crohn's disease (CD) is classified as those patients who are ambulatory, with <10 % weight loss, are eating and drinking without abdominal mass, tenderness, obstructive symptoms, or fever, and endoscopically they have non-progressive mild findings. Initial evaluation of mild CD should focus on assessment for high-risk features requiring more aggressive therapy. In contrast to moderate-to-severe disease, where therapy is focused on mucosal healing, the management of mild CD is focused on symptom management, while exposing the individual to minimal therapeutic risks. Budesonide is the most commonly used medication for mild CD given its safety profile. Assessment of inflammatory markers, in concert with computed-tomography (CT) or magnetic resonance (MR) enterographies and endoscopic studies, should be considered in clinical remission to ensure that mucosal inflammation is not present. Endoscopic inflammation can precede clinical recurrence. Individuals with mild CD require routine vaccination, monitoring for iron-deficiency anemia and vitamin D deficiency, and colorectal cancer screening when appropriate.

The role of small bowel endoscopy in small bowel Crohn's disease: when and how?

Endoscopy has a crucial role in the diagnosis, management, and surveillance of inflammatory bowel disease (IBD). It contributes in supporting the diagnosis of IBD with the clinical history, physical examination, laboratory findings, and targeted biopsies. Furthermore, endoscopy has a significant role in assessing disease activity and distribution in treatment efficacy evaluation, post-surgical recurrence risk, and cancer surveillance in patients with long-lasting illness. Endoscopy also provides therapeutic potential for the treatment of IBD, especially with stricture dilatation and treatment of bleeding. Small bowel (SB) endoscopy (capsule endoscopy and device-assisted enteroscopy) and cross-sectional radiologic imaging (computed tomography enterography and magnetic resonance enterography) have become important diagnostic options to diagnose and treat patients with SB Crohn's disease. We reviewed the present role of SB endoscopy in patients with SB Crohn's disease.

The Diagnostic Role of Magnetic Resonance Enterography as a Complementary Test to Colonoscopy in Active Crohn's Disease

BACKGROUND

According to recent studies comparing magnetic resonance enterography (MRE) with ileocolonoscopy for assessing inflammation of small bowel and colonic segments in adults with active Crohn’s disease (CD), we aimed to compare the accuracy of these two diagnostic methods in Iranian population.

METHODS

During 2013-2014 a follow-up study was done on 30 patients with active CD in a gastroenterology clinic affiliated to Tehran University of Medical Sciences. MRE and ileocolonoscopy were performed for all the patients. All statistical analyses were performed using SPSS (version 18) and p-value<0.05 was considered as statistically significant.

RESULTS

Of the 30 patients with active CD, 11(36.7%) were men and 19 (63.3%) were women with mean age of 37.30±13.66 years (range: 19-67 years). MRE had sensitivity and specificity of 50% and 90% with positive predictive value (PPV) and negative predictive value (NPV) of 71.43 and 78.26, respectively for localizing sigmoid lesions and ileum had sensitivity and specificity of 84.21 and 45.45 with PPV and NPV of 72.73 and 62.50, respectively.

CONCLUSION

While moderate sensitivity and high specificity of MRE in localizing colonic lesions makes it an appropriate confirmatory test after colonoscopy, the reported high sensitivity and moderate specificity of MRE versus colonoscopy in detecting ileal lesions makes it a suitable screening test for ileal lesions. Finally we can conclude that MRE can be an important complementary test to colonoscopy in detecting active disease.

Magnetic Resonance Enterography Healing and Magnetic Resonance Enterography Remission Predicts Improved Outcome in Pediatric Crohn Disease

BACKGROUND

Mucosal healing predicts clinical remission and improved outcomes in patients with Crohn disease (CD). Magnetic resonance enterography (MRE) is a noninvasive imaging modality that can assess small and large bowel wall inflammation. Evidence suggests that MRE may be an acceptable alternative to evaluate mucosal healing over endoscopy. Our objective is to determine whether MRE remission predicts clinical remission at follow-up in children with CD.

METHODS

We performed an institutional review board-approved retrospecitve chart review using our prospectively maintained MRE CD database. Inclusion criteria were all children who underwent an MRE more than 6 months after diagnosis with CD who had follow-up of at least 1 year from imaging.

RESULTS

A total of 101 children with CD underwent MRE, a median of 1.3 years from diagnosis with a median follow-up of 2.8 years after MRE. Active inflammation was detected in 65 MRE studies, whereas 36 MRE studies demonstrated MRE remission. A total of 88.9% of children demonstrating MRE remission were in clinical remission at follow-up, whereas only 44.6% of those demonstrating MRE active inflammation achieved clinical remission. Children demonstrating MRE-active inflammation were more likely to have a change in medication (44.6% vs 8.3%) and more likely to undergo surgery (18.5% vs 2.8%).

CONCLUSIONS

MRE remission is associated with clinical remission at follow-up at least 1 year after MRE. MRE remission was associated with fewer medication changes and fewer surgeries suggesting that, similar to endoscopic remission, MRE remission demonstrates improved outcome. Additional research is needed to confirm that MRE can be used as a surrogate for mucosal healing.

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.

Imaging of perianal fistulizing Crohn's disease

Perianal fistula is a complication of Crohn's disease that carries a high morbidity. It is a channel that develops between the lower rectum, anal canal and perianal or perineal skin. The development of perianal fistulas typically connotes a more aggressive disease phenotype and may warrant escalation of treatment to prevent poor outcomes over time. Based on fistula anatomy, debris can form inside these tracts and cause occlusion, which subsequently leads to abscess formation, fever and malaise. The clinical presentation is often with complaints of pain, continuous rectal drainage of fecal matter as well as malodorous discharge. Considering that the presence of fistulas often indicates refractory and aggressive disease, early identification of its presence is important. Some patients may not have the classic symptoms of fistulizing disease at presentation and others may have significant scarring and/or pain from previous fistulizing episodes, which can make an accurate assessment on physical exam alone problematic. As a result, utilizing diagnostic imaging is the best means of identifying the early signs of perianal fistulas or abscess formation in these patients. Several imaging modalities exist which can be used for diagnosis and management. Endoscopic ultrasound and pelvic MRI are considered the most useful in establishing the diagnosis. However, a combination of multiple imaging modalities and/or examination under anesthesia is probably the most ideal. Incomplete characterization of the fistula tract(s) extent or the presence of abscess carries a high morbidity and far-reaching personal expense for the patient - promoting worsening of the disease.

The multidisciplinary health care team in the management of stenosis in Crohn's disease

Background

Stricture formation is a common complication of Crohn’s disease (CD), occurring in approximately one-third of all patients with this condition. Our aim was to summarize the available epidemiology data on strictures in patients with CD, to outline the principal evidence on diagnostic imaging, and to provide an overview of the current knowledge on treatment strategies, including surgical and endoscopic options. Overall, the unifying theme of this narrative review is the multidisciplinary approach in the clinical management of patients with stricturing CD.

Methods

A Medline search was performed, using “Inflammatory Bowel Disease”, “stricture”, “Crohn’s Disease”, “Ulcerative Colitis”, “endoscopic balloon dilatation” and “strictureplasty” as keywords. A selection of clinical cohort studies and systematic reviews were reviewed.

Results

Strictures in CD are described as either inflammatory or fibrotic. They can occur de novo, at sites of bowel anastomosis or in the ileal pouch. CD-related strictures generally show a poor response to medical therapies, and surgical bowel resection or surgical strictureplasty are often required. Over the last three decades, the potential role of endoscopic balloon dilatation has grown in importance, and nowadays this technique is a valid option, complementary to surgery.

Conclusion

Patients with stricturing CD require complex clinical management, which benefits from a multidisciplinary approach: gastroenterologists, pediatricians, radiologists, surgeons, specialist nurses, and dieticians are among the health care providers involved in supporting these patients throughout diagnosis, prevention of complications, and treatment.

Distinct management issues with Crohn's disease of the small intestine

PURPOSE OF REVIEW

Small bowel Crohn's disease can present with clinical challenges that are specific to its location. In this review, we address some of the areas that present particular problems in small bowel Crohn's disease.

RECENT FINDINGS

A key issue specific to small bowel Crohn's disease relates to its diagnosis given that access to the small bowel is limited. Radiological advances, particularly in small bowel ultrasonography and MRI, as well as the introduction of capsule endoscopy and balloon enteroscopy are helping to address this. In addition, our ability to differentiate small bowel Crohn's disease from other causes of inflammation, such as tuberculosis, is improving on the basis of better understanding of the features that differentiate these conditions. It is also becoming apparent that jejunal Crohn's disease represents a distinct disease phenotype with potentially worse clinical outcomes. Finally, because it is a rare complication, our understanding of small bowel cancer associated with Crohn's disease remains limited. Recent publications are, however, starting to improve our knowledge of this condition.

SUMMARY

Although small bowel Crohn's disease presents specific management issues not seen in patients with Crohn's disease elsewhere in the gastrointestinal tract, our knowledge of how to manage these is improving.