Comparison of MR enterography and histopathology in the evaluation of pediatric Crohn disease

ACR Appropriateness Criteria® Crohn Disease-Child

Crohn disease is an inflammatory condition of the gastrointestinal tract with episodes of exacerbation and remission occurring in children, adolescents, and adults. Crohn disease diagnosis and treatment depend upon a combination of clinical, laboratory, endoscopic, histological, and imaging findings. Appropriate use of imaging provides critical information in the settings of diagnosis, assessment of acute symptoms, disease surveillance, and therapy monitoring. Four variants are discussed. The first variant discusses the initial imaging for suspected Crohn disease before established diagnosis. The second variant pertains to appropriateness of imaging modalities during suspected acute exacerbation. The third variant is a substantial discussion of recommendations related to disease surveillance and monitoring of Crohn disease. Finally, panel recommendations and discussion of perianal fistulizing disease imaging completes the document. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Diagnostic Accuracy of Magnetic Resonance Enterography in the Evaluation of Colonic Abnormalities in Crohn's Disease: A Systematic Review and Meta-Analysis

OBJECTIVES

To Evaluate the diagnostic performance of magnetic resonance enterography (MRE) for detecting colonic involvement of Crohn's disease (CD).

MATERIALS AND METHODS

A systematic search of the electronic bibliographic databases was conducted. The inclusion criteria of published original articles were: (1) Utilized MRE to evaluate colon; (2) Patients with documented CD by colonoscopy; (3) Provided crude data of diagnostic performance in the large bowel; (4) Performed segmental evaluation. The colorectal segments were defined as the right colon, transverse colon, left colon, and rectum. A hierarchical bivariate method was used for analysis.

RESULTS

Eleven articles (12 populations and 987 patients) were included. The pooled sensitivity and specificity of the studies were 69% (95% CI: 0.52-0.82) and 95% (95% CI:0.92-0.97), respectively (AUC = 0.95). The pooled positive and negative likelihood ratios were 14 (95% CI:7.5-26.3) and 0.31 (95% CI:0.19-0.51), respectively. Regarding segments, the left colon had the highest sensitivity (60%) and lowest specificity (92%), while the transverse colon showed lowest sensitivity (49%) and highest specificity (95%). Comparing the age groups, MRE sensitivity and specificity was 80% and 95%, versus 62% and 94%, in pediatrics and adults respectively.

CONCLUSION

MRE has a high specificity to detect colon pathologies in CD, while the sensitivity is low. Therefore, the test has a high value to rule in CD, while negative results are not sufficient to rule it out. Meanwhile, considering the higher sensitivity rate of the test in pediatrics, it has the potential to be used as a first-line investigation.

Diagnostic Accuracy of Non-Invasive Imaging for Detection of Colonic Inflammation in Patients with Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

Endoscopy is the gold standard for objective assessment of colonic disease activity in inflammatory bowel disease (IBD). Non-invasive colonic imaging using bowel ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) may have a role in quantifying colonic disease activity. We reviewed the diagnostic accuracy of these modalities for assessment of endoscopically or histopathologically defined colonic disease activity in IBD. We searched Embase, MEDLINE, and the Web of Science from inception to 20 September 2021. QUADAS-2 was used to evaluate the studies' quality. A meta-analysis was performed using a bivariate model approach separately for MRI and US studies only, and summary receiver operating characteristic (ROC) curves were obtained. CT studies were excluded due to the absence of diagnostic test data. Thirty-seven studies were included. The mean sensitivity and specificity for MRI studies was 0.75 and 0.91, respectively, while for US studies it was 0.82 and 0.90, respectively. The area under the ROC curves (AUC) was 0.88 (95% CI, 0.82 to 0.93) for MRI, and 0.90 (95% CI, 0.75 to 1.00) for US. Both MRI and US show high diagnostic accuracy in the assessment of colonic disease activity in IBD patients.

Impact of Magnetic Resonance Imaging in Management of Pediatric Crohn's Disease

Crohn's disease (CD) is a chronic illness and radiographic evaluation is frequently used. Consequently, pediatric patients with CD who are diagnosed in childhood are at risk for high levels of radiation exposure during their lifetimes. We sought to evaluate the impact of magnetic resonance enterography (MRE) in management of pediatric patients with known or suspected Crohn's disease. A retrospective review of patients with known or suspected CD who underwent MRE for new onset of symptoms was conducted. All demographic data, clinical history, and results of all radiographic, endoscopic, and pathology studies were recorded. Twenty-eight patients with known or suspected CD underwent 31 MRE examinations. MRE showed active disease in 16 (52%), fistula or abscess in seven (22%), and no evidence of active disease in eight (26%). Sixty-five per cent of patients underwent MRE with no other radiation-based imaging used. Surgical intervention was deemed necessary after the MRE in 16 per cent. In all cases, surgical findings were consistent with MRE results. Nearly 60 per cent of patients with CD are managed based on the findings of MRE without additional radiographic evaluation. Based on the results of this retrospective study, we propose a clinical pathway for use of MRE in patients with known or suspected CD with new onset of symptoms.

Role of MR Enterography in Evaluation of Disease Activity in Pediatric Crohn’s Disease: Correlation between MR Enterography and Pediatric Crohn’s Disease Activity Index Scores

Objectives The aim of the study was to assess the role of MR Enterography (MRE) in the diagnosis and follow-up of children with Crohn’s disease (CD) and to correlate disease activity indices with known MRE features of active disease.

Methods This was a retrospective study including 24 patients (median age 11 years, 17 males) with clinically and histologically proven CD who underwent MRE. Two previously validated MRE scores—Magnetic Resonance Enterography Global Score (MEGS) and CD MRI index (CDMI)—were calculated. A correlative analysis was made between the Pediatric Crohn’s Disease Activity Index (PCDAI) score and MRE scores as well as individually with each MR variable. Comparison of both the MR scores was made between patients with different disease activity.

Results MEGS and PCDAI scores showed strong positive correlation (r = 0.724, p = < 0.001); CDMI and PCDAI scores showed moderate positive correlation (r = 0.661, p = 0.0004). There was statistically significant difference in the MR scores between patients grouped by clinical activity. Among individual MR variables, mural thickness and enhancement best predicted the disease activity.

Conclusions MRE-based scores and findings correlate with clinical activity in pediatric CD. Thereby, MRE can be considered a valuable tool in the management of CD, predicting disease activity and offering a potential alternative to endoscopy in monitoring patients during follow-up.

Comparison of two small bowel distending agents for enterography in pediatric small bowel imaging

OBJECTIVE

To evaluate the ability of pediatric patients with known or suspected inflammatory bowel disease to ingest a new oral distending agent at CT or MR enterography (CTE/MRE), and to determine the impact on small bowel (SB) distension and diagnostic confidence.

MATERIALS AND METHODS

The study design is that of retrospective review of pediatric patients who underwent CTE or MRE from January 2014 to June 2016. Patients ingested low-concentration barium suspension or flavored beverage containing sorbitol and mannitol. The need for nasogastric tube (NGT) administration, amount ingested, emesis, distal extent of contrast, SB distension, terminal ileum (TI) transverse dimension, and diagnostic confidence in TI disease were assessed. Three radiologists each blindly reviewed a subset of the studies.

RESULTS

Of the total 591 scans in 504 patients, 316 scans used low-concentration barium suspension and 275 scans flavored beverage. Nearly all consumed the entire amount (97% vs. 96%). Low-concentration barium suspension exams required NGT more often (7% [23/316] vs. 1% [3/275]; p < 0.0003), and tended to have more emesis (3% [9/316] vs. 1% [3/275]; p = 0.13). Diagnostic confidence score was nearly identical (p = 0.94). Qualitative and quantitative analyses showed no difference in SB distension, except for distension of mid-ileum (flavored beverage > low-concentration barium suspension; p = 0.02). Flavored beverage exams demonstrated a slight increase in distal extent of luminal distension (p = 0.02).

CONCLUSIONS

A new flavored beverage distends small bowel as well as low-concentration barium suspension, with decreased requirement for NGT insertion and improved distal extent of luminal distension, and without any decrease in diagnostic confidence in the presence or the absence of TI disease.

Capsule Endoscopy Complements Magnetic Resonance Enterography and Endoscopy in Evaluating Small Bowel Crohn's Disease

Aims

Wireless capsule endoscopy (WCE) and magnetic resonance enterography (MRE) are increasingly utilized to evaluate the small bowel (SB) in Crohn's disease (CD). The primary aims were to compare the ability of WCE and MRE to detect SB inflammation in children with newly diagnosed CD, and in the terminal ileum (TI) to compare them to ileo-colonoscopy. Secondary aims were to compare diagnostic accuracy of WCE and MRE and changes in Paris classification after each study.

Methods

Patients (10 to 17 years of age) requiring ileo-colonoscopy for suspected CD were invited to participate. Only patients with endoscopic/histologic evidence of CD underwent MRE and WCE. SB inflammation and extent were documented and comparative analyses performed.

Results

Of 38 initially recruited subjects, 20 completed the study. WCE and MRE were similarly sensitive in identifying active TI inflammation (16 [80%] versus 12 [60%]) and any SB inflammation (17 [85%] versus 16 [80%]). However, WCE detected more extensive SB disease than MRE with active inflammation throughout the SB in 15 [75%] versus 1 [5%] patient (P < 0.001). Moreover, WCE was more likely to detect proximal SB disease (jejunum and ileum) compared to MRE (85% versus 50%, P = 0.04). Overall, the Paris classification changed in 65% and 85% of patients following MRE and WCE, respectively.

Conclusions

WCE is as sensitive as MRE for identifying active TI inflammation, but appears more sensitive in identifying more proximal SB inflammation. In the absence of concern regarding stricturing or extra-luminal disease WCE can be considered for the evaluation of suspected SB CD.

Diagnostic accuracy of non-contrast magnetic resonance enterography in detecting active bowel inflammation in pediatric patients with diagnosed or suspected inflammatory bowel disease to determine necessity of gadolinium-based contrast agents

BACKGROUND

Pediatric patients with inflammatory bowel disease (IBD) are at increased risk of gadolinium deposition given the potential need for multiple contrast-enhanced magnetic resonance enterography (MRE) exams over their lifetime.

OBJECTIVE

To determine whether gadolinium-based contrast agents are necessary in assessing active bowel inflammation on MRE in pediatric patients with known or suspected IBD.

MATERIALS AND METHODS

We conducted a retrospective study of 77 patients (7-18 years; 68.8% male) with known (n=58) or suspected (n=19) IBD and endoscopy with biopsy performed within 30 days of MRE without and with contrast evaluated bowel and non-bowel findings. During three visual analysis sessions, two radiologists reviewed pre-, post-, and pre-/post-contrast MRE images. A third radiologist independently reviewed 27 studies to assess inter-reader reliability. We used Cohen kappa (κ), Fleiss kappa, (κ_F), McNemar test, and sensitivity and specificity to compare MRE readings to combined endoscopic/histopathological findings (the reference standard).

RESULTS

The pre- and pre-/post-contrast-enhanced MRE vs. combined endoscopic/histopathological results had moderate agreement (85.7%; κ 0.713, P<0.001; P-value 0.549). Compared to combined endoscopy/histopathology, pre- vs. pre-/post-contrast sensitivity (67%, confidence interval [CI] 0.53-0.79 vs. 67%, CI 0.53-0.79) and specificity (80%, CI 0.59-0.92 vs. 68%, CI 0.46-0.84) varied little (κ 0.42, P<0.001 and κ 0.32, P=0.003, respectively). The three readers had moderate agreement (85.2%; κ 0.695, P=0.001; P-value 0.625). More penetrating complications were identified following contrast administration (P-value 0.04).

CONCLUSION

Use of a contrast agent does not improve the detection of active inflammation in the terminal ileum and colon compared to non-contrast MRE, although use of a contrast agent does aid in the detection of penetrating disease.

Can diffusion weighting replace gadolinium enhancement in magnetic resonance enterography for inflammatory bowel disease in children?

BACKGROUND

Contrast-enhanced MRI is often used for diagnosis and follow-up of children with inflammatory bowel disease.

OBJECTIVE

To compare the accuracy of diffusion-weighted MRI (DWI) to contrast-enhanced MRI in children with known or suspected inflammatory bowel disease.

MATERIALS AND METHODS

This retrospective, consecutive study included 55 children. We used ileo-colonoscopy and histology as the reference standard from the terminal ileum to the rectum, and contrast-enhanced MRI as the reference standard proximal to the terminal ileum. DWI and contrast-enhanced MRI sequences were independently reviewed and compared per patient and per segment to these reference standards and to the follow-up for each child.

RESULTS

We obtained endoscopic data for 340/385 colonic and ileal segments (88%). The rate of agreement per segment between DWI and endoscopy was 64%, and the rate of agreement between contrast-enhanced MRI and endoscopy was 59%. Per patient, sensitivity and specificity of bowel wall abnormalities as compared to the endoscopy were 87% and 100% for DWI, and 70% and 100% for contrast-enhanced MRI, respectively. Positive and negative predictive values were, respectively, 100% and 57% for DWI, and 96% and 41% for contrast-enhanced MRI. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of DWI compare to contrast-enhanced MRI in the segments proximal to the terminal ileum were 90%, 98%, 90%, 98% and 96%, respectively.

CONCLUSION

The diagnostic performance of DWI is competitive to that of contrast-enhanced MRI in children with known or suspected inflammatory bowel disease.

Magnetic resonance enterography evaluation of Crohn disease activity and mucosal healing in young patients

MR enterography (MRE) has become the primary imaging modality for assessing Crohn disease in young patients because of its lack of ionizing radiation, superior soft-tissue contrast, and cross-sectional capability to evaluate disease activity as well as extraluminal and extra-intestinal complications. MRE has been extensively validated against both histological and endoscopic references as a noninvasive imaging biomarker of Crohn disease activity. More recent studies have also validated MRE as a noninvasive biomarker of mucosal healing, an important endpoint of Crohn disease therapy. In this review, we summarize the current evidence supporting the use of MRE features as imaging biomarkers of Crohn disease activity and treatment response.

Diagnostic Performance of Magnetic Resonance Enterography for Detection of Active Inflammation in Children and Adolescents With Inflammatory Bowel Disease: A Systematic Review and Diagnostic Meta-analysis

Importance

Magnetic resonance (MR) enterography has the advantage over other techniques of being noninvasive, lacking ionizing radiation, and demonstrating excellent soft-tissue contrast to evaluate pediatric patients with inflammatory bowel disease (IBD).

Objective

To evaluate the diagnostic performance of MR enterography for detection of active inflammation in children and adolescents with known or suspected IBD.

Data Sources

A search of MEDLINE and EMBASE up to January 2, 2017, was performed to identify studies. Search terms included child, pediatric, adolescent, Crohn disease, inflammatory bowel disease, and magnetic resonance enterography. The search was limited to English-language publications.

Study Selection

Studies evaluating the diagnostic performance of MR enterography for detection of active inflammation in pediatric patients with known or suspected IBD were selected. Two reviewers independently assessed the eligibility of the selected articles.

Data Extraction and Synthesis

The study was performed and reported in accordance with the PRISMA guidelines. Pooled summary estimates of sensitivity and specificity were calculated using hierarchical logistic regression modeling.

Main Outcomes and Measures

The diagnostic performance of MR enterography for detection of active inflammation in pediatric patients with known or suspected IBD was the primary outcome. Subgroup analyses and meta-regression were performed.

Results

Eighteen original articles involving a total of 687 patients were included. The summary sensitivity was 83% (95% CI, 75%-89%), the summary specificity was 93% (95% CI, 90%-95%), and the area under the hierarchical summary receiver operating characteristic curve was 0.95 (95% CI, 0.93-0.97). The Higgins I2 statistics demonstrated substantial heterogeneity in terms of sensitivity (I2 = 84.1%) and specificity (I2 = 68.8%). Based on per-patient analysis, the summary sensitivity was 86% (95% CI, 78%-91%) and specificity was 91% (95% CI, 82%-96%). In meta-regression, among the various potential covariates, scanner manufacturer was associated with study heterogeneity.

Conclusions and Relevance

Magnetic resonance enterography, which is a noninvasive, radiation-free modality, demonstrates high diagnostic performance in the diagnosis of active inflammation in pediatric patients with IBD, especially at the per-patient level.

Colonic inflammation in pediatric inflammatory bowel disease: detection with magnetic resonance enterography

BACKGROUND

Colonic involvement in pediatric inflammatory bowel disease is common. Magnetic resonance (MR) enterography is considered the best imaging modality for pediatric inflammatory bowel disease evaluation. It is unclear whether the lack of a dedicated large bowel preparation prevents a reliable colonic assessment.

OBJECTIVE

To determine the diagnostic performance of standard MR enterography in detecting and grading colonic inflammatory activity.

MATERIALS AND METHODS

We retrospectively evaluated children who underwent both MR enterography and ileocolonoscopy with biopsies <4 weeks apart. Two radiologists independently reviewed MR examinations and quantified inflammation in each of the five colonic segments using a standardized MR score system. Findings were compared with histological examination of the corresponding segment. Mann-Whitney, Kruskal-Wallis, Jonckheere-Terpstra and Bland-Altman statistics were used.

RESULTS

One hundred seventy-five segments from 37 examinations were included. MR enterography diagnostic performance for inflammation was as follows: sensitivity 94% (95% confidence interval [CI]: 90-97%), specificity: 64% (95% CI: 57-71%). A significant positive correlation was found between MR score and inflammatory activity histologically graded (P<0.001, Jonckheere-Terpstra test). The interobserver agreement was good (mean difference between MR enterography scores was -0.03; limits of agreement -2.8 to 2.7).

CONCLUSION

Standard MR enterography is sensitive for the detection of actively inflamed colonic segments. MR enterography might provide useful information for guiding biopsies and its role as an alternative to ileocolonoscopy in monitoring colonic disease activity in children should be further investigated.

The role of imaging in the preoperative assessment of children with inflammatory colitis

BACKGROUND

Accurate diagnosis of Crohn's disease or ulcerative colitis is essential for surgical planning. This study compared the accuracy, safety, and utility of small bowel follow-through (SBFT) and magnetic resonance enterography (MRE) for detecting small bowel (SB) involvement preoperatively.

METHODS

A retrospective review of children who underwent colectomy for inflammatory bowel disease (2000-2014) was performed. Preoperative SBFT and MRE were independently reviewed by two radiologists blinded to clinical data. Gold standard for diagnosis was surgical pathology.

RESULTS

68 patients (36 female) were included. 45 patients had SBFT prior to colectomy, 17 patients had MRE, and 6 both. Interrater reliability for radiologic interpretation was 90% (SBFT) and 91% (MRE). Mean study durations were 190min (SBFT) and 59min (MRE). Median effective dose for SBFT was 1.5mSv, while MRE involved no ionizing radiation. Specificities for diagnosing SB involvement were 87.5% (SBFT) and 94% (MRE). 54 patients underwent subtotal colectomy and ileostomy, 12 restorative proctocolectomy, and 2 colectomy with ileorectal anastomosis. Preoperative imaging correlated with surgical pathology in 83% (SBFT) and 90% (MRE).

CONCLUSION

MRE is at least as effective as SBFT for assessing SB disease in children with colitis prior to colectomy. MRE requires less time and does not expose children to ionizing radiation. Retrospective Case Series, Level 4 Evidence.

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

BACKGROUND

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

ACR Appropriateness Criteria Crohn Disease

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

Assessing pediatric ileocolonic Crohn's disease activity based on global MR enterography scores

OBJECTIVES

This study was aimed at correlating a magnetic resonance index of activity (MaRIA) and a magnetic resonance enterography global score (MEGS) with activity indexes in a paediatric population with Crohn's disease (CD).

METHODS

This retrospective study included 32 paediatric patients (median age 14.5 years, 18 male) with proven CD who underwent magnetic resonance enterography (MRE). A correlation analysis was performed on the MRE-based scores, the simplified endoscopic score for CD (SES-CD), the paediatric Crohn's disease activity index (PCDAI), and C-reactive protein (CRP) levels. Based on PCDAI, comparison of both global MaRIA and MEGS was made between patients with mild and moderate/severe disease activity.

RESULTS

Global MaRIA correlated with SES-CD (r = 0.70, p = 0.001) and PCDAI (r = 0.42, p = 0.016). MEGS correlated with PCDAI (r = 0.46, p = 0.007) and CRP levels (r = 0.35, p = 0.046). MEGS differed significantly (p = 0.027) between patients grouped by clinical disease severity.

CONCLUSIONS

MRE-based global scores correlated with clinical indexes of CD activity. Therefore, they represent a potential useful tool to predict CD activity and severity, as well as a possible promising alternative to endoscopy, to monitor paediatric patients with CD during their follow-up.

KEY POINTS

• MRE is widely used to for accurate assessment of CD. • Global MaRIA and MEGS have been suggested as indicators of CD activity. • Paediatric studies comparing MRE-based global scores with clinical CD activity are lacking. • Such scores can serve as predictors of CD activity/severity in paediatric patients. • MRE offers an alternative to clinical score/endoscopy for paediatric CD monitoring.

MR enterography: how to deliver added value

MR enterography (MRE) is increasingly vital to the diagnosis and follow-up of children with Crohn disease. This diagnostic test, which can provide valuable information regarding the presence of intestinal inflammation, intestinal and intra-abdominal complications, and extra-intestinal disease-related manifestations, has the potential to directly impact both medical and surgical decision-making. Consequently, it is imperative that the interpretation and reporting of these examinations provide as much clinical information as possible. This article reviews specific ways radiologists can provide added value when interpreting MRE examinations in the setting of pediatric Crohn disease by (1) establishing the true extent of disease involvement, (2) subjectively and objectively assessing response to medical treatment and (3) accurately characterizing disease-related complications.

Longitudinal diffusion-weighted imaging changes in children with small bowel Crohn's disease: preliminary experience

PURPOSE

Crohn's disease has been associated with restricted diffusion in diseased small bowel segments on diffusion-weighted imaging (DWI). However, data addressing longitudinal changes in DWI findings and their potential clinical ramifications in the pediatric population are lacking. The purpose of this study was to follow DWI changes in diseased small bowel segments between serial magnetic resonance enterography (MRE) examinations, and to correlate these changes with other imaging parameters and clinical status.

METHODS

This retrospective study evaluated patients less than 21 years of age undergoing serial MRE examinations including DWI for Crohn's disease involving the small bowel. All patients carried a diagnosis of Crohn's disease established by pathology or corroborative clinical and imaging findings. Longitudinal changes in mean apparent diffusion coefficient (ADC) values within the wall of affected small bowel lesions were recorded and normalized to both unaffected bowel and skeletal muscle. ADC changes were correlated with qualitative imaging phenotype, as reflected by a defined set of non-DWI imaging parameters, as well as with clinical disease activity.

RESULTS

Seventeen lesions were evaluated longitudinally, distributed among 13 patients (9 boys and 4 girls, mean age at baseline 16.6 years), each of whom had two sequential MRE examinations. Lesions demonstrating a fibrostenotic imaging phenotype at follow-up MRE had a significantly lower change in mean ADC value between examinations than lesions that did not have a fibrostenotic imaging phenotype (p = 0.0005), an effect that persisted when ADC values were normalized to unaffected bowel and skeletal muscle. Across all studies, lesions with a fibrostenotic imaging phenotype had lower ADC values than those with an inflammatory imaging phenotype, which were in turn lower than those with a normal imaging phenotype (p = 0.0001).

CONCLUSION

Patterns of longitudinal DWI changes in Crohn's disease may differ among small bowel lesions depending upon their specific natural histories. These findings may assist in the evaluation of the ADC value as a potential imaging surrogate when evaluating lesion status, particularly as it pertains to relative contributions of inflammation and fibrosis.

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.

Prospective evaluation of free-breathing diffusion-weighted imaging for the detection of inflammatory bowel disease with MR enterography in childhood population

OBJECTIVE

To evaluate prospectively the performance of diffusion-weighted imaging (DWI) for the detection of active lesions on MR enterography (MRE) in children with inflammatory bowel disease (IBD).

METHODS

MRE of 48 children (mean age 13 years) with suspected or known IBD were blindly analysed by 2 independent readers for the presence of active lesions. Two sets of imaging including DWI and gadolinium-enhanced imaging (GEI) were reviewed. A reader consensus was obtained. The gold standard was histopathological findings. In patient-level analysis and segment-level analysis, sensitivity and specificity were calculated for DWI and GEI and compared using McNemar's test or logistic random-effects models.

RESULTS

At least 1 active lesion was confirmed in 42 (87.5%) children. Sensitivity and specificity for the detection of at least one lesion were 88.1% (95% CI, 74.3-96.1) and 83.3% (95% CI, 35.9-99.6), respectively, for DWI and 66.7% (95% CI, 50.4-80.4) and 83.3% (95% CI, 35.9-99.6), respectively, for GEI. In segment-level analysis, sensitivity and specificity for the detection of specific segment lesions were 62.5% (95% CI, 48.1-75) and 97.1% (95% CI, 93.5-98.7), respectively, for DWI and 45.7% (95% CI, 30.8-61.3) and 98.2% (95% CI, 95.3-99.4), respectively, for GEI. The sensitivity of DWI was significantly better than that of GEI per patient (p = 0.004) and per segment (p = 0.028).

CONCLUSION

DWI demonstrates better performance than GEI for the detection of active lesions in children with IBD.

ADVANCES IN KNOWLEDGE

Examination with no intravenous injection-DWI can replace T1 weighted images when paediatric patients are screened with MRE for IBD. Examination performed in free breathing is better tolerated by children.

Magnetic resonance colonography including diffusion-weighted imaging in children and adolescents with inflammatory bowel disease: do we really need intravenous contrast?

OBJECTIVES

Magnetic resonance colonography (MRC) is a well-accepted, noninvasive imaging modality for the depiction of inflammatory bowel disease. Diffusion-weighted imaging (DWI) is very helpful to display inflammatory lesions. The aim of this retrospective study was to assess whether intravenous contrast is needed to depict inflammatory lesions in bowel magnetic resonance imaging if DWI is available.

MATERIALS AND METHODS

Thirty-seven patients (23 females, 14 males; mean age, 14.6 years) underwent MRC on a 1.5-T scanner (MAGNETOM Avanto; Siemens). Contrast-enhanced T1-weighted (ce-T1-w) sequences and DWI sequences in axial and coronal planes (b = 50, 500, 1000) were acquired. Two reviewers evaluated (1) DWI, (2) ce-T1-w MRC, as well as (3) DWI and ce-T1-w MRC concerning lesion conspicuity. The preferred b value was assessed. Colonoscopy was performed within 1 week, including biopsies serving as the reference standard. Sensitivities and specificities were calculated, and interobserver variability was assessed.

RESULTS

Mean sensitivity and specificity of the 2 readers for the depiction of inflammatory lesions were 78.4%/100% using ce-T1-w MRC, 95.2%/100% using DWI, and 93.5%/100% combining both imaging techniques compared with colonoscopy including results of the histopathological samples. In 6 patients, inflammatory lesions were only detected by DWI; in another 6 patients, DWI detected additional lesions. The κ values for the 2 readers were excellent (k = 0.92-0.96). The preferred b value with the best detectability of the lesion was b1000 in 28 of the 30 patients (93.3%) with restricted diffusion.

CONCLUSIONS

Diffusion-weighted imaging of the bowel identified inflammatory lesions with high accuracy and revealed lesions that were not detectable with ce-T1-w imaging alone. A b value of 1000 showed the best lesion detectability.

Magnetic resonance enterography of Crohn's disease

Magnetic resonance enterography (MRE) has been reported to be a useful modality for the evaluation of luminal inflammation and extraintestinal complications in Crohn's disease (CD). A recent study indicated that the diagnostic ability of MRE was comparable to the diagnostic ability of other devices, such as ileocolonoscopy. MRE can be performed repeatedly because there is no radiation exposure. Therefore, MRE is useful as a method of follow-up for younger patients with established CD. It is useful for evaluating the efficacy of medical treatments, such as biologics. MRE can detect small intestinal lesions even if the endoscope does not pass through the stenosis. The concerns of availability of expertise and the costs associated with MRE should be addressed so MRE can be widely used for CD patients in the near future.

Cinematic magnetic resonance enterography for non-organic abdominal pain in infants and children

BACKGROUND

Recurrent non-organic abdominal pain is the most commonly diagnosed medical problem in children. However, excluding small bowel disease remains a challenge. We evaluated our exclusion criteria for organic small intestinal diseases in pediatric patients with recurrent non-organic abdominal pain using cinematic magnetic resonance (cine-MR) enterography.

METHODS

The non-intestinal organic (non-IO) group as classified by the Rome III criteria system and the intestinal organic (IO) group consisted of 81 and 19 patients, with 35 and 12 male and 46 and 7 female patients with an age range of 5-18 and 4-15 years (average 10.5 and 10.5 years), respectively. Cine-MR enterography was performed by dynamically balanced first-field-echo imaging with thick-slice water-selective excitation without breath holding. In our original small intestinal motility test, cine-MR enterography was taken at three different times (fasting state [P1], immediately after [P2] and 30 min after [P3] drinking liquid material), with images taken sequentially for 5 min at each time-point to evaluate the motion of water in the gastrointestinal tract. Positive findings for organic intestinal problems were concluded when persistent visible intestinal loops appeared in both the P1 and P2 phases.

RESULTS

Cine-MR enterography showed 6/81 (7.4%) and 18/19 (94.7%) (P < 0.01) positive cases of organic intestinal problems in the non-IO and IO groups, respectively. Positive and negative predictive values of this examination were 78.3% and 97.4%, respectively.

CONCLUSIONS

The unique capabilities of cine-MR enterography technology in this clinical setting render it an important additional diagnostic tool when specific disease management issues must be addressed.

Imaging in the evaluation of the young patient with inflammatory bowel disease: what the gastroenterologist needs to know

Imaging plays a pivotal role in the diagnosis and management of children and young adults with inflammatory bowel disease. The clinician is presented with numerous imaging options, and it can be challenging to decide which test is the best option. In this article we review the present imaging techniques available in the evaluation of inflammatory bowel disease, with emphasis on the advantages, disadvantages, and radiation burden of each test. Finally, we highlight a few common clinical scenarios and propose an imaging algorithm to approach these diagnostic challenges.

Evolving role of MRI in Crohn's disease

MR enterography is playing an evolving role in the evaluation of small bowel Crohn's disease (CD). Standard MR enterography includes a combination of rapidly acquired T2 sequence, balanced steady-state acquisition, and contrast enhanced T1-weighted gradient echo sequence. The diagnostic performance of these sequences has been shown to be comparable, and in some respects superior, to other small bowel imaging modalities. The findings of CD on MR enterography have been well described in the literature. New and emerging techniques such as diffusion-weighted imaging (DWI), dynamic contrast enhanced MRI (DCE-MRI), cinematography, and magnetization transfer, may lead to improved accuracy in characterizing the disease. These advanced techniques can provide quantitative parameters that may prove to be useful in assessing disease activity, severity, and response to treatment. In the future, MR enterography may play an increasing role in management decisions for patients with small bowel CD; however, larger studies are needed to validate these emerging MRI parameters as imaging biomarkers.

I.v. glucagon use in pediatric MR enterography: effect on image quality, length of examination, and patient tolerance

OBJECTIVE

The objective of our study was to evaluate the use of i.v. glucagon in pediatric patients undergoing MR enterography.

SUBJECTS AND METHODS

Forty-seven patients underwent clinical MR enterography examinations consisting of identical breath-hold T1-weighted 3D gradient-recalled echo fat-saturated pulse sequences before and after i.v. glucagon administration. Images were reviewed in a blinded manner by two pediatric radiologists to determine the effect of glucagon on visualization of the small and large bowel. Image time stamps were documented separately to determine how this adjunctive medication affected examination length. A separate cohort of 50 patients was evaluated for glucagon-related symptoms, including nausea and emesis. Exact binomial testing was performed to establish whether overall visualization of the bowel and visualization of the terminal ileum were better on images with i.v. glucagon. The two-tailed Wilcoxon signed rank test was used to compare Likertlike scores for bowel visualization before and after i.v. glucagon administration.

RESULTS

Glucagon improved overall bowel visualization in 40 of 47 (85%) examinations for reader 1 (p < 0.0001) and 36 of 47 (77%) for reader 2 (p = 0.0001). Visualization of the terminal ileum was improved after glucagon administration in 29 of 47 (62%) examinations for both readers (p = 0.03). Glucagon improved visualization of the small bowel for reader 1 (mean score on 5-point Likertlike scale: 3.3 ± 1.0 [SD] vs 2.2 ± 0.7, respectively; p < 0.0001) and reader 2 (3.4 ± 1.1 vs 2.5 ± 0.9; p < 0.0001). Glucagon also improved large-bowel visualization for reader 1 (3.3 ± 0.9 vs 3.0 ± 0.8; p = 0.005) and reader 2 (3.4 ± 1.1 vs 3.0 ± 1.0; p = 0.002). On average, the use of glucagon added 13.7 minutes to the examination. Twenty-four of 50 (48%) patients self-reported glucagon-related nausea and four patients experienced emesis.

CONCLUSION

I.v. glucagon improves bowel visualization at pediatric MR enterography, increases examination length, and commonly causes nausea. Fewer than 10% of patients experience glucagon-related emesis in our practice.

MRI diffusion-weighted imaging (DWI) in pediatric small bowel Crohn disease: correlation with MRI findings of active bowel wall inflammation

BACKGROUND

Restricted diffusion on diffusion-weighted imaging (DWI) sequences during magnetic resonance enterography (MRE) has been shown in segments of bowel affected by Crohn disease. However, the exact meaning of this finding, particularly within the pediatric Crohn disease population, is poorly understood.

OBJECTIVE

The purpose of this study was to determine the significance of bowel wall restricted diffusion in children with small bowel Crohn disease by correlating apparent diffusion coefficient (ADC) values with other MRI markers of disease activity.

MATERIALS AND METHODS

A retrospective review of pediatric patients (≤ 18 years of age) with Crohn disease terminal ileitis who underwent MRE with DWI at our institution between May 1, 2009 and May 31, 2011 was undertaken. All of the children had either biopsy-proven Crohn disease terminal ileitis or clinically diagnosed Crohn disease, including terminal ileal involvement by imaging. The mean minimum ADC value within the wall of the terminal ileum was determined for each examination. ADC values were tested for correlation/association with other MRI findings to determine whether a relationship exists between bowel wall restricted diffusion and disease activity.

RESULTS

Forty-six MRE examinations with DWI in children with terminal ileitis were identified (23 girls and 23 boys; mean age, 14.3 years). There was significant negative correlation or association between bowel wall minimum ADC value and established MRI markers of disease activity, including degree of bowel wall thickening (R = (-)0.43; P = 0.003), striated pattern of arterial enhancement (P = 0.01), degree of arterial enhancement (P = 0.01), degree of delayed enhancement (P = 0.045), amount of mesenteric inflammatory changes (P < 0.0001) and presence of a stricture (P = 0.02). ADC values were not significantly associated with bowel wall T2-weighted signal intensity, length of disease involvement or mesenteric fibrofatty proliferation.

CONCLUSION

Increasing bowel wall restricted diffusion (lower ADC values) is associated with multiple MRI findings that are traditionally associated with active inflammation in pediatric small bowel Crohn disease.

Systematic review: MRI enterography for assessment of small bowel involvement in paediatric Crohn's disease

BACKGROUND

Barium meal enteroclysis (BM) is the recommended imaging technique for small bowel inaccessible by ileo-colonoscopy when diagnosing paediatric-onset inflammatory bowel disease, but it has poor sensitivity and involves ionising radiation. MRI enterography (MRE) is an alternative methodology.

AIMS

To critically appraise the published evidence on MRE in the assessment of Paediatric inflammatory bowel disease by systematic review.

METHODS

Review of all English language data reporting MRE for the investigation of patients <18 years with known or suspected IBD. Primary searches of Medline (Jan 1950-April 2012), Cinahl (1966-April 2012) and Pubmed (Jan 1950-April 2012) were performed using keyword and MeSH terms; IBD; Magnetic resonance imaging; small bowel imaging; EMBASE was then searched. Two authors independently assessed the quality of studies using the quality assessment of diagnostic accuracy studies tool.

RESULTS

Searches yielded 930 035 hits, combination word searches limited to 1983 titles. Fifty-two studies were fully reviewed, 41 were excluded due to lack of paediatric data. Eleven studies of 496 children were included. All studies used endoscopy as the reference test. 10/496 patients required jejunal intubation for bowel preparation. Meta-analysis of six comparable studies gave a pooled sensitivity and specificity for MRE detection of active terminal ileal Crohn's disease of 84% and 97% respectively. Studies displayed heterogeneity in bowel preparation, scanning technique, reporting methodology and timing of ileo-colonoscopy in relation to MRE. In three studies comparing BM, MRE had greater sensitivity and specificity.

CONCLUSIONS

MRE is a sensitive and specific tool for diagnosis in paediatric inflammatory bowel disease. Technical considerations require refinement and standardisation; however, MRE has no radiation. Current data suggest that MRE should supersede BM as the SB imaging technique in centres with appropriate expertise.

A novel biphasic oral contrast solution for enterographic studies

PURPOSE

To compare the efficacy and patients' tolerance of a new mixed biphasic oral contrast solution with routine biphasic oral contrast agent in magnetic resonance (MR) enterography (MRE).

MATERIALS AND METHODS

Thirty-seven patients (group 1) had MRE with the new mixture, whereas 14 patients (group 2) had MRE with biphasic oral contrast agent (lactulose). Magnetic resonance enterography images were evaluated by 2 experienced radiologists. Each intestinal segment was evaluated for luminal distension (LD), distinction from the surrounding tissue (wall conspicuity), and the confidence of radiologist for evaluation of the specified segment (radiological evaluation confidence). Comparisons between the 2 groups were performed using the Mann-Whitney U test. Interrater and intrarater agreement values were obtained. In addition, patients' acceptability and tolerance were assessed.

RESULTS

The new mixture was more effective than the oral contrast agent used in group 2 for LD, wall conspicuity, and radiological confidence. The values of interrater and intrarater agreement in scoring LD, wall conspicuity, and radiological confidence were generally moderate.

CONCLUSION

Our new mixture allowed good-quality enterographic images, and this solution was well tolerated by patients. In addition, this mixture is useful for evaluation of small bowels and colonic segments. We suggest the use of it for enterographic examinations.

Small-bowel MRI in children and young adults with Crohn disease: retrospective head-to-head comparison of contrast-enhanced and diffusion-weighted MRI

BACKGROUND

Small-bowel MRI based on contrast-enhanced T1-weighted sequences has been challenged by diffusion-weighted imaging (DWI) for detection of inflammatory bowel lesions and complications in patients with Crohn disease.

OBJECTIVE

To evaluate free-breathing DWI, as compared to contrast-enhanced MRI, in children, adolescents and young adults with Crohn disease.

MATERIALS AND METHODS

This retrospective study included 33 children and young adults with Crohn disease ages 17 ± 3 years (mean ± standard deviation) and 27 matched controls who underwent small-bowel MRI with contrast-enhanced T1-weighted sequences and DWI at 1.5 T. The detectability of Crohn manifestations was determined. Concurrent colonoscopy as reference was available in two-thirds of the children with Crohn disease.

RESULTS

DWI and contrast-enhanced MRI correctly identified 32 and 31 patients, respectively. All 22 small-bowel lesions and all Crohn complications were detected. False-positive findings (two on DWI, one on contrast-enhanced MRI), compared to colonoscopy, were a result of large-bowel lumen collapse. Inflammatory wall thickening was comparable on DWI and contrast-enhanced MRI. DWI was superior to contrast-enhanced MRI for detection of lesions in 27% of the assessed bowel segments and equal to contrast-enhanced MRI in 71% of segments.

CONCLUSION

DWI facilitates fast, accurate and comprehensive workup in Crohn disease without the need for intravenous administration of contrast medium. Contrast-enhanced MRI is superior in terms of spatial resolution and multiplanar acquisition.

Radiation exposure in children with inflammatory bowel disease

PURPOSE OF REVIEW

Radiation exposure due to medical imaging has grown exponentially over the past two decades and the awareness has increased in the last few years with a number of articles in scientific publications and lay press. Radiation increases the risk of cancer and is particularly a concern in children. Limiting radiation exposure is most important in children, who are more sensitive to radiation, and specifically in children with a chronic lifelong disease such as inflammatory bowel disease (IBD).

RECENT FINDINGS

Children with IBD and specifically Crohn's disease demonstrate high exposure to ionizing radiation due to medical imaging. The yearly rate of medical imaging radiation exposure may seem small at approximately 3-5 mSv/year, which is only slightly higher than typical background radiation (3 mSv/year). However, this extra yearly radiation exposure to children with a lifelong chronic disease may increase the risk of cancer. Additionally, recent literature suggests that some children with more severe disease are exposed to high radiation doses within the first few years of diagnosis. Imaging modalities that do not utilize radiation, such as MRI and ultrasonography, have demonstrated utility in diagnosing and managing IBD and are particularly important for children.

SUMMARY

Pediatricians caring for children with chronic diseases should consider radiation exposure and limit exposure when possible. Future quality outcome benchmarks should include limiting exposure to radiation in children with chronic diseases.

Inflammatory bowel disease in children and adolescents: assessing the diagnostic performance and interreader agreement of magnetic resonance enterography compared to histopathology

RATIONALE AND OBJECTIVES

The purpose of this study was to determine the accuracy of magnetic resonance enterography (MRE) compared to histopathology in the evaluation of pediatric inflammatory bowel disease and to assess interreader reliability for image interpretation.

MATERIALS AND METHODS

All magnetic resonance enterography studies performed for known or suspected inflammatory bowel disease between July 2009 and July 2010 were retrospectively reviewed by two pediatric radiologists. Exams were evaluated for signs of enteric inflammation and extraenteric disease. A five-point, Likert-type scale was used to assess the overall likelihood of active inflammation, with scores ≥ 3 considered positive. Cohen's κ coefficient was calculated to assess interreader agreement. A subset of patients who had undergone ileocolonoscopy or surgery with confirmed histopathology within 45 days of MRE were used to assess the accuracy of MRE for detecting active inflammation in the terminal ileum and large bowel.

RESULTS

A total of 91 magnetic resonance enterography studies were reviewed. Of these, 45 had comparison histopathology within 45 days. The overall sensitivity of MRE for detecting active inflammation compared to ileocolonoscopy was 92% for both readers, while specificity was 100% for reader 1 and 75% for reader 2. Of the individual parameters evaluated, mucosal hyperenhancement and bowel wall thickening were the most sensitive indicators of active inflammation, each having sensitivity of 86% and specificity of 88%. Cohen's κ coefficient was 0.59, indicating moderate agreement between the readers.

CONCLUSIONS

MRE has high overall diagnostic accuracy for detecting active bowel inflammation in pediatric patients compared to ileocolonoscopy and demonstrates moderate interreader reliability.

Magnetic resonance enterography and wireless capsule endoscopy in the evaluation of patients with inflammatory bowel disease

BACKGROUND

Magnetic resonance enterography (MRE) is increasingly used in children due to growing concerns of radiation.

OBJECTIVE

To determine the performance of MRE, imaging findings were compared to wireless capsule endoscopy (WCE) and histology results in children with/or suspected inflammatory bowel disease (IBD).

MATERIALS AND METHODS

Pathology and WCE reports were retrospectively reviewed in 23 patients who had MRE.

RESULTS

The sensitivity of MRE was 75.0% while the sensitivity of WCE was 77.8%.

CONCLUSION

MRE and WCE are complementary techniques in evaluation of the small bowel in IBD.

MRI in Crohn's disease--current and future clinical applications

Crohn's disease is a chronic, disabling disease that, over time, can lead to irreversible bowel damage. MRI can be used to diagnose and assess the activity, severity and complications of Crohn's disease; however, the role of MRI in therapeutic monitoring of changes in disease-related intestinal damage is still to be defined. Objective, validated MRI-based scores have been developed to assess the activity of Crohn's disease; these indices are based on the extent and severity of intestinal inflammation, postoperative recurrence and perianal disease. MRI is accurate, safe, reproducible and can allow repeated evaluations of patients without radiation exposure. Evidence that MRI might be valuable in the therapeutic monitoring of patients with Crohn's disease is increasing and, in combination with endoscopy and surgical history, this imaging technique could enable clinicians to assess Crohn's-disease-related intestinal damage. MRI could, therefore, have a crucial role in a future 'damage-driven' treatment paradigm--in which imaging is used to monitor intestinal damage and medication use is targeted to prevent the accumulation of further damage. This damage-driven therapeutic approach could potentially change the course of Crohn's disease.

MRI in Crohn's disease--current and future clinical applications

Crohn's disease is a chronic, disabling disease that, over time, can lead to irreversible bowel damage. MRI can be used to diagnose and assess the activity, severity and complications of Crohn's disease; however, the role of MRI in therapeutic monitoring of changes in disease-related intestinal damage is still to be defined. Objective, validated MRI-based scores have been developed to assess the activity of Crohn's disease; these indices are based on the extent and severity of intestinal inflammation, postoperative recurrence and perianal disease. MRI is accurate, safe, reproducible and can allow repeated evaluations of patients without radiation exposure. Evidence that MRI might be valuable in the therapeutic monitoring of patients with Crohn's disease is increasing and, in combination with endoscopy and surgical history, this imaging technique could enable clinicians to assess Crohn's-disease-related intestinal damage. MRI could, therefore, have a crucial role in a future 'damage-driven' treatment paradigm--in which imaging is used to monitor intestinal damage and medication use is targeted to prevent the accumulation of further damage. This damage-driven therapeutic approach could potentially change the course of Crohn's disease.