Early Biological Therapy Within 12 Months of Diagnosis Leads to Higher Transmural Healing Rates in Crohn's Disease.

BACKGROUND & AIMS: Transmural healing (TH) is emerging as a potential Crohn's disease (CD) treatment target. Early biological treatment seems to be associated with improved disease outcomes, but its impact on TH remains unclear. We aimed to assess the impact of early biological treatment initiation on TH and its influence on CD prognosis. METHODS: This multicenter retrospective study included adult patients with CD starting biological therapy. TH was assessed using magnetic resonance enterography (MRE) at 12 ± 6 months post-therapy initiation, with radiological examinations reviewed by blinded expert radiologists. TH was defined as complete normalization of all MRE parameters. Timing of biological therapy initiation was analyzed as a continuous variable, with optimal cutoff determined using the Youden index and clinical relevance. Logistic regression with propensity score-adjusted analysis was used to assess the association between early biological therapy initiation and TH. Long-term outcomes (bowel damage progression, CD-related surgery, CD-flare hospitalization, and therapy escalation) were evaluated. RESULTS: Among 154 patients with CD, early biological therapy initiation within 12 months of diagnosis was associated with significantly higher TH rates (adjusted odds ratio [aOR], 3.23; 95% confidence interval [CI], 1.36-7.70; P < .01), which persisted after adjusting for previous biological therapy use (aOR, 2.82; 95% CI, 1.13-7.06; P = .03). Time-to-event analysis demonstrated that TH was significantly associated with reduced time until bowel damage progression (adjusted hazard ratio [aHR], 0.28; 95% CI, 0.10-0.79; P = .02), CD-related surgery (aHR, 0.21; 95% CI, 0.05-0.88; P = .03) and therapy escalation (aHR, 0.35; 95% CI, 0.14-0.88; P = .02), independently of early biological therapy. CONCLUSIONS: Early initiation of biological therapy within 12 months of diagnosis significantly increases TH rates, leading to improved long-term outcomes in patients with CD.

Volumetric measurement of terminal ileal Crohn's disease by magnetic resonance enterography: a feasibility study.

OBJECTIVES: Magnetic resonance enterography (MRE) interpretation of Crohn's disease (CD) is subjective and uses 2D analysis. We evaluated the feasibility of volumetric measurement of terminal ileal CD on MRE compared to endoscopy and sMARIA, and the responsiveness of volumetric changes to biologics. METHODS: CD patients with MRE and contemporaneous CD endoscopic index of severity-scored ileocolonoscopy were included. A centreline was placed through the terminal ileum (TI) lumen defining the diseased bowel length on the T2-weighted non-fat saturated sequence, used by two radiologists to independently segment the bowel wall to measure volume (phase 1). In phase 2, we measured disease volume in patients treated with biologics, who had undergone pre- and post-treatment MRE, with treatment response classified via global physician assessment. RESULTS: Phase 1 comprised 30 patients (median age 29 (IQR 24, 34) years). Phase 2 included 12 patients (25 years (22, 38)). In phase 1, the mean of the radiologist-measured volumes was used for analysis. The median disease volume in those with endoscopically active CD was 20.9 cm3 (IQR 11.3, 44.0) compared to 5.7 cm3 (2.9, 9.8) with normal endoscopy. The mean difference in disease volume between the radiologists was 3.0 cm3 (limits of agreement -21.8, 15.9). The median disease volume of patients with active CD by sMARIA was 15.0 cm3 (8.7, 44.0) compared to 2.85 cm3 (2.6, 3.1) for those with inactive CD. Pre- and post-treatment median disease volumes were 28.5 cm3 (26.4, 31.2), 11 cm3 (4.8, 16.6), respectively in biological responders, vs 26.8 cm3 (12.3, 48.7), 40.1 cm3 (10, 56.7) in non-responders. CONCLUSION: Volumetric measurement of terminal ileal CD by MRE is feasible, related to endoscopy and sMARIA activity, and responsive to biologics. CLINICAL RELEVANCE STATEMENT: Measuring the whole volume of diseased bowel on MRE in CD is feasible, related to how biologically active the disease is when assessed by endoscopy and by existing MRE activity scores, and is sensitive to treatment response. KEY POINTS: MRE reporting for CD is subjective and uses 2D images rather than assessing the full disease volume. Volumetric measurement of CD relates to endoscopic activity and shows reduced disease volumes in treatment responders. This technique is an objective biomarker that can assess disease activity and treatment response, warranting validation.

Development, Validation, and Evaluation of the Pediatric Inflammatory Crohn's Magnetic Resonance Enterography Index From the ImageKids Study.

BACKGROUND & AIMS: Cross-sectional imaging is important in the assessment of transmural inflammation in Crohn's disease (CD). Small bowel involvement is often more extensive in pediatric CD, requiring a panentering measuring tool. We undertook to develop a magnetic resonance enterography (MRE)-based index that would measure inflammation in all segments of the intestine, without rectal contrast. METHODS: Children with CD underwent ileocolonoscopy and MRE and half were prospectively followed for 18 months when MRE was repeated. Item generation and reduction were performed by a Delphi panel of pediatric radiologists, a systematic literature review, a cross-sectional study of 48 MREs, and a steering committee. Formatting and weighting were performed using multivariate modeling adjusted by a steering committee. MREs were read locally and centrally. Reliability, validity, and responsiveness were determined using several clinimetric and psychometric approaches. RESULTS: Thirty items were initially generated and reduced to 5 using regression analysis on 159 MREs: wall thickness, wall diffusion weighted imaging, ulcerations, mesenteric edema, and comb sign. In the validation cohort of 81 MREs, the weighted global PICMI correlated well with the radiologist global assessment (r = 0.85; P < .001) and with the simple endoscopic score in a subsample with ileocolonic disease (r = 0.63; P < .001). Interobserver and test-retest reliability were high (interclass correlation coefficients, 0.84; 95% confidence interval [CI], 0.79-0.87; and 0.81, 95% CI, 0.65-0.90, respectively; both P < .001). Excellent responsiveness was found at repeated visits (n = 116 MREs; area under the receiver operating characteristic curve 0.96; 95% CI, 0.93-0.99). Transmural healing was defined as PICMI ≤10 and response as a change of >20 points with excellent discriminative validity (area under the receiver operating characteristic curve = 0.96; 95% CI, 0.93-0.99). CONCLUSIONS: The PICMI is a valid, reliable, and responsive index for assessing transmural inflammation in pediatric CD. It scores the entire bowel length and does not require intravenous contrast or rectal enema and, therefore, is suitable for use in children. (ClinicalTrials.gov, Number: NCT01881490.).

Infliximab response associates with radiologic findings in bio-naïve Crohn's disease.

OBJECTIVES: Since a reliable model for predicting infliximab (IFX) benefits in bio-naïve Crohn's disease (CD) is still lacking, we constructed a magnetic resonance enterography (MRE)-based model to predict the risk of loss of response to IFX in bio-naïve patients with CD. METHODS: This retrospective multicenter study enrolled 188 bio-naïve patients with CD who underwent MRE before IFX therapy. Therapeutic outcomes were determined based on clinical symptoms and endoscopic findings within 52 weeks. The areas of bowel wall segmentation were decided by two experienced radiologists in consensus. Texture features were extracted using the least absolute shrinkage and selection operator, and a radiomic model was built using multivariate logistic regression. The model performance was validated by receiver operating characteristic, calibration curve, and decision curve analysis. RESULTS: The area under the curve of radiomic model was 0.88 (95% confidence interval: 0.82-0.95), and the model provided clinical net benefit in identifying the loss of response to IFX and exhibited remarkable robustness among centers, scanners, and disease characteristics. The high-risk patients defined by the radiomic model were more likely to develop IFX nonresponse than low-risk patients (all p < 0.05). CONCLUSIONS: This novel pretreatment MRE-based model could act as an effective tool for the early estimation of loss of response to IFX in bio-naïve patients with CD. KEY POINTS: • Magnetic resonance enterography model guides infliximab therapy in Crohn's disease. • The model presented significant discrimination and provided net clinical benefit. • Model divided patients into low- and high-risk groups for infliximab failure.

Validation of the simplified magnetic resonance index of activity by using DWI without gadolinium enhancement to evaluate bowel inflammation in Crohn's disease.

OBJECTIVES: To validate the modified simplified magnetic resonance index of activity (sMARIA) score using DWI on non-contrast magnetic resonance enterography (MRE) to evaluate active inflammation in patients with Crohn's disease (CD), compared to the original sMARIA scoring system, with and without contrast enhancement. METHODS: This retrospective study included 275 bowel segments from 55 CD patients who underwent ileocolonoscopy and MRE within a 2-week period. Two blinded radiologists evaluated original sMARIA on both conventional MRE (CE-sMARIA) and non-contrast MRE (T2-sMARIA). Modified sMARIA was then evaluated using non-contrast MRE, replacing ulcerations with DWI grades. Three scoring systems were compared for diagnostic accuracy of active inflammation, correlation with simple endoscopic score (SES)-CD, and interobserver reproducibility. RESULTS: The AUC of modified sMARIA for detecting active inflammation (0.863, 95% confidence interval [0.803-0.923]) was significantly higher than T2-sMARIA (0.827 [0.773-0.881], p = 0.017), and comparable to CE-sMARIA (0.908 [0.857-0.959], p = 0.122). CE-sMARIA, T2-sMARIA, and modified sMARIA all showed moderate correlation with SES-CD (r = 0.795, 0.722, and 0.777, respectively). Interobserver reproducibility of diffusion restriction (κ, 0.686 [0.602-0.770]) was significantly better than ulcers on conventional MRE (κ, 0.382 [0.212-0.552]; p = 0.001) and T2-weighted image (κ, 0.312 [0.034-0.590]; p = 0.012). CONCLUSIONS: Modified sMARIA using DWI can improve the diagnostic performance of sMARIA on non-contrast MRE, showing comparable performance to sMARIA using contrast-enhanced MRE. KEY POINTS: • DWI can improve the diagnostic performance of non-contrast magnetic resonance enterography (MRE) for assessing active inflammation in patients with Crohn's disease. • Modified simplified magnetic resonance index of activity (sMARIA) using DWI grades in place of ulcers showed comparable diagnostic performance to sMARIA using conventional MRE with contrast-enhanced sequences.

DWI ratios: New indexes for Crohn's disease activity at magnetic resonance enterography?

BACKGROUND: The aim of the study was to provide radiologists and clinicians a rapid tool for assessment of intestinal inflammation in Crohn's disease (CD) patients through quantification of diffusion-weighted imaging (DWI) signal intensity while performing magnetic resonance enterography (MRE). MATERIALS AND METHODS: A monocentric retrospective study was conducted between September 2018 and July 2021 on CD patients who underwent MRE. Two radiologists measured signal intensity on DWI scans at the highest b-value (800 s/mm2) within pathologic intestinal walls, lymph nodes, spleen and psoas muscle and calculated the relative ratios. Spearman, Mann-Whitney and Jonckheere-Terpstra tests were applied for estimating correlation among ratios, significant differences between the two patient groups and determining the trend in relation to endoscopic classes. Wilcoxon's and Cronbach's alpha tests were employed for comparison of DWI measurements and ratios between the two observers. RESULTS: Fifty-nine patients were enrolled in the study. In the non-surgical group, correlation has been found among Simple Endoscopic Score for Crohn's Disease (SES-CD) classes and the different ratios: bowel/spleen (p = 0.034), bowel/psoas (p = 0.008) and bowel/lymph node (p = 0.010). Within the surgical group, positive correlation was found only between bowel/lymph node ratio and bowel/psoas ratio (p = 0.014). The J-T test demonstrated an increasing monotonic trend for bowel/psoas ratio and bowel/lymph node ratio and SES-CD classes. Inter-reader evaluation demonstrated no statistical differences for DWI measurements and high degree of concordance for the final ratios. CONCLUSION: DWI ratios correlate with endoscopic classes in non-surgical patients and have inter-observer reproducibility.

Avoiding contrast-enhanced sequences does not compromise the precision of the simplified MaRIA for the assessment of non-penetrating Crohn's disease activity.

OBJECTIVES: Patients with Crohn's disease (CD) require multiple assessments with magnetic resonance enterography (MRE) from a young age. Standard MRE protocols for CD include contrast-enhanced sequences. Gadolinium deposits in brain tissue suggest avoiding gadolinium could benefit patients with CD. This study aimed to compare the accuracy of the simplified Magnetic Resonance Index of Activity (sMaRIA) calculated with and without contrast-enhanced sequences in determining the response to biologic drugs in patients with CD. METHODS: This post hoc analysis of a prospective study included patients with CD with endoscopic ulceration in ≥ 1 intestinal segment starting biologic drug therapy. Two blinded radiologists used the sMaRIA to score images obtained at baseline and week 46 of treatment first using only unenhanced sequences (T2-sMaRIA) and 1 month later using both unenhanced and enhanced images (CE-sMaRIA). We calculated the rates of agreement between T2-sMaRIA, CE-sMaRIA, and ileocolonoscopy for different conceptualizations of therapeutic response. RESULTS: A total of 46 patients (median age, 36 years [IQR: 28-47]) were included. Agreement with ileocolonoscopy was similar for CE-sMaRIA and T2-sMaRIA in identifying ulcer healing (kappa = 0.74 [0.55-0.93] and 0.70 [0.5-0.9], respectively), treatment response (kappa = 0.53 [0.28-0.79] and 0.44 [0.17 - 0.71]), and remission (kappa = 0.48 [0.22-0.73] and 0.43 [0.17-0.69]). The standardized effect size was moderate for both CE-sMaRIA = 0.63 [0.41-0.85] p < 0.001 and T2-sMaRIA = 0.58 [0.36-0.80] p < 0.001. CONCLUSIONS: sMaRIA with and without contrast-enhanced images accurately classified the response according to different therapeutic endpoints determined by ileocolonoscopy. KEY POINTS: • The simplified Magnetic Resonance Index of Activity is accurate for the assessment of Crohn's disease activity, severity, and therapeutic response, using four dichotomic components that can be evaluated without the need of using contrast-enhanced sequences, representing a practical and safety advantage, but concerns have been expressed as to whether the lack of contrast sequences may compromise precision. • The simplified Magnetic Resonance Index of Activity can assess the response to biologic therapy in patients with Crohn's disease without the need for intravenous contrast agents obtaining comparable results without and with contrast-enhanced sequences. • Avoiding intravenous contrast agents could reduce the duration of the MRE examination and its cost and would increase the acceptance and safety of MRE in clinical research in patients with Crohn's disease.

CHRONIC PSEUDO-OBSTRUCTION OF THE SIGMOID COLON: A CASE REPORT.

Chronic intestinal pseudo-obstruction (CIPO) is a rare syndrome characterized by signs of intestinal obstruction lasting for 6 months or more, in the absence of a definitive cause of obstruction. We report a case of CIPO in a 49-year-old female patient with a 6-month history of ongoing irregular bowel movements, manifested as constipation and diarrhea accompanied by abdominal pain and bloated feeling. Contrast-enhanced abdominal computed tomography and magnetic resonance enterography revealed focal thickening of a segment of the lienal flexure and intermittent areas of wider and narrower caliber along the sigmoid colon. No signs of a definitive cause of obstruction were found, but evidence for dolichosigma was revealed, which was later confirmed with colonoscopy. Due to persisting symptoms, the patient agreed to elective resection of the sigmoid colon. Following the procedure, symptoms regressed with a significant improvement in the quality of life. The patient has been regularly monitored in an outpatient setting and reports absence of the symptoms since the procedure. Pathophysiology of the resected section revealed more prominent lymphatic tissue, follicular arrangement, and reactively altered germinal centers, which can suggest CIPO.

The clinical significance of biliary findings in magnetic resonance enterography of patients with inflammatory bowel disease.

Purpose: Given the association of inflammatory bowel disease (IBD) and primary sclerosing cholangitis (PSC), we aimed to investigate the clinical relevance of abnormal hepatobiliary findings on magnetic resonance enterography (MRE) of IBD patients considering the risk of over- or underestimation of PSC at MRE. Material and methods: Using the MRE dataset of patients referring to a tertiary hospital and the National Registry of Crohn's and Colitis, 69 MREs, including 23 IBD-PSC, 23 IBD-without PSC, and 23 healthy controls (HC), were retrospectively reviewed by 2 experienced radiologists blinded to the clinical data, to evaluate hepatobiliary abnormalities. Sensitivity, specificity, and likelihood ratios were calculated. Results: Bile duct irregularities were the most common finding in the IBD-PSC group, with a frequency of 91%. Intra- and extrahepatic bile duct (IHBD and EHBD) irregularities were observed in 87% and 78% of PSC patients, respectively. Higher frequency of IHBD and EHBD wall thickening, bile duct dilation, EHBD stricture, and periportal oedema were observed in the IBD-PSC group. Peribiliary T2-weighted hyperintensities and contrast-enhancement were significantly more common in the IBD-PSC group than in the IBD and HC groups (48% and 35%, respectively) (p < 0.001). Detection of biliary irregularities on MRE had a specificity of 94% (95% CI: 82-99%), a sensitivity of 91% (95% CI: 72-99%), and a positive likelihood ratio of 14.0 (95% CI: 4.7-42.1) for the diagnosis of PSC. Conclusions: This study emphasizes the importance of assessing and reporting hepatobiliary abnormalities visible in the MRE of patients with IBD to avoid a delayed diagnosis of PSC.

Novel Associations Between Genome-Wide Single Nucleotide Polymorphisms and MR Enterography Features in Crohn's Disease Patients.

BACKGROUND: Patient genetic polymorphism is associated with Crohn's clinical behavior; however, its association with magnetic resonance enterography (MRE) imaging appearance is not known. PURPOSE: To analyze a set of known Crohn's disease (CD)-related single nucleotide polymorphisms for associations with MRE imaging phenotype and frequency of imaging. STUDY TYPE: Retrospective. POPULATION: 54 patients (mean age 40 years; 32 females and 22 males) with established CD from 2009 to 2016 who underwent baseline MRE and genetic testing for the presence of 168 single nucleotide polymorphisms (SNPs) potentially associated with inflammatory bowel disease. FIELD STRENGTH/SEQUENCE: 1.5T or 3T clinical scanners, standard MRE clinical pulse sequences, including T2 -weighted single-shot fast spin echo, balanced steady-state free precession, T2 -weighted fast spin echo fat-suppressed, and T1 -weighted fat-suppressed pre- and postcontrast imaging. ASSESSMENT: Three readers (all body imaging fellowship-trained radiologists) independently evaluated all imaging for the presence or absence of active disease and penetrating complications. Date of onset and frequency of endoscopies and cross-sectional imaging (CSI) were recorded. Disease behavior and distribution were categorized according to the Vienna and Montreal classifications, respectively. STATISTICAL TESTS: Student's t-test and Fisher's exact test were used to assess significance of continuous and categorical variables, respectively. A hidden Markov model statistical knockoff approach was also applied for the analysis of genetic-imaging associations, with corrected P < 0.05 considered significant. RESULTS: MRE demonstrated active bowel inflammation in 42 (78%) patients, strictures in 13 (28%), and fistulae in 13 (28%). The SNP rs1292053 (RBS6KB1) was highly associated with small bowel inflammation and luminal narrowing, with observed frequencies of association 0.66 and 0.39, respectively (P = 0.001). rs6062504 (Decoy receptor 3) was associated with lower age of onset (P = 0.012), higher proportion of early disease onset patients (P = 0.012), and higher average number of CSI/year (P = 0.014). DATA CONCLUSION: This study demonstrated significant associations between CD genotype and MRE phenotype and frequency of cross-sectional imaging. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2.

MR enterography grading of pediatric ileocolonic Crohn disease activity based on a single bowel segment.

BACKGROUND: Ileocolonoscopy with histology has been considered the gold standard for Crohn disease (CD) diagnosis and monitoring. Over the last years, magnetic resonance enterography (MRE) has become more and more popular, representing a valid non-invasive technique. OBJECTIVE: To propose a simplified MRE score, the pediatric CD magnetic resonance index (PCDMRI), based only on the most affected bowel segment, to grade active inflammation in children with CD. MATERIALS AND METHODS: Two radiologists retrospectively evaluated MRE images of children with histopathology-proven CD. The PCDMRI was based on six mural and perimural variables assessed for the most affected bowel segment (chosen by visual inspection of the key bowel wall imaging findings associated with active inflammation), and five extramural per-examination features. Correlation analysis was performed between both the PCDMRI and the MRE global score (based on all the affected segments) and the pediatric clinical disease activity index (PCDAI), the simple endoscopic score for CD (SES-CD), serum C-reactive protein (CRP) and fecal calprotectin (fC). Inter-reader reproducibility of the scoring system was estimated. Agreement on disease location between MRE and ileocolonoscopy was evaluated. RESULTS: The study involved 42 children for a total of 80 MRE. PCDMRI and global score positively correlated with PCDAI, SES-CD, CRP and fC. Inter-reader reproducibility was 91%. Agreement on disease location was substantial. CONCLUSION: The PCDMRI and the global score resulted equally correlated with the PCDAI, suggesting a high impact of the most affected segment on symptoms. The PDCMRI may be a useful non-invasive tool for a rapid and reproducible grading of the disease activity in children with ileocolonic CD.

Can Conventional and Diffusion-Weighted MR Enterography Biomarkers Differentiate Inflammatory from Fibrotic Strictures in Crohn's Disease?

Background and Objectives: To retrospectively assess the value of magnetic resonance enterography (MRE) parameters derived from conventional and diffusion weighted imaging (DWI) sequences to differentiate fibrotic strictures from inflammatory ones in adult patients with Crohn's disease (CD), using surgical specimens as the histopathological reference standard. Material and Methods: Twenty-three patients with CD who had undergone surgical resection of ileal strictures with full-thickness histopathologic analysis within 3 months from preoperative MRE were included. Two radiologists blinded to histopathology in consensus evaluated the following biomarkers on MRE images matched to resected pathological specimens: T1 ratio, T2 ratio, enhancement pattern, mural thickness, pre-stenotic luminal diameter, and apparent diffusion coefficient (ADC). A blinded pathologist graded stricture histological specimens with acute inflammation score (AIS) and fibrosis score (FS). MRE measurements were correlated with the reference standard. Results: Inflammation and fibrosis coexisted in 78.3% of patients. T2 ratio was reduced in patients with severe fibrosis (p = 0.01). Pre-stenotic bowel dilatation positively correlated with FS (p = 0.002). The ADC value negatively correlated with FS (p < 0.001) and was different between FS grades (p < 0.05). The area under the receiver operating characteristic curve for discriminating between none and mild/moderate-severe bowel wall fibrosis was 0.75 for pre-stenotic bowel dilatation (sensitivity 100%, specificity 44.4%) and 0.97 for ADC (sensitivity 80%, specificity 100%). Conclusions: Inflammation and fibrosis often coexist in CD bowel strictures needing surgery. The combination of parameters derived from conventional MR sequences (T2 ratio, pre-stenotic dilatation) and from DWI (ADC) may provide a contribution to detect and grade bowel fibrosis in adult CD patients.

The mutually complementary role of magnetic resonance enterography and conventional enteroclysis in patients with complicated and/or advanced stage of Crohn's disease.

AIM: To assess the diagnostic significance of magnetic resonance enterography (MRE) and conventional enteroclysis (CE) in patients with complicated and/or advanced stage of Crohn's disease. METHODS: Patients with abnormal CE findings suggestive of mural and/or extramural involvement with the diagnosis or pre-diagnosis of CD are evaluated. After real-time bowel distension by enteroscopic examination, the patients with advanced or complicated stage were taken to the MRE examination in the same session. Mucosal-mural-extramural and activation findings, presence of stenosis/stricture, skip lesions and the mean duration of exams were evaluated with both CE and MRE. The superiority of one method over the other relative to these findings was evaluated. RESULTS: A total of 110 patients evaluated by CE had the findings of CD. Of these, 24 patients with abnormal CE findings suggestive of advanced mural and extramural involvements were subsequently evaluated with MRE. CE was superior to MRE in the depiction of early superficial mucosal changes (aphthous-linear ulcer), cobblestone pattern (p = 0.002, p < 0.01), obstruction (p = 0.004, p < 0.01), and differentiation between the string sign and stricture. MRE was superior to conventional enteroclysis in mural and perienteric findings of bowel thickening, fibro-fatty proliferation, abscess (p = 0.016, p 0.05). CONCLUSION: CE and MRE are mutually complementary imaging modalities in CD staging, evaluation of activation findings, and detection of complications (Tab. 3, Fig. 8, Ref. 23).

The value of magnetic resonance enterography in diagnostic difficulties associated with Crohn's disease.

PURPOSE: The diagnosis of Crohn's disease (CD), one of the inflammatory bowel diseases (IBD), along with ulcerative colitis (UC), is often challenging due to the limitations of small intestine visualisation. Magnetic resonance enterography (MRE) enables imaging of intraluminal and extraintestinal complications without ionizing radiation. The objective of this study is to select CD-related MRE features and determine the feasibility of this technique to indicate a group of patients that should be subjected to more invasive diagnostic procedures. MATERIAL AND METHODS: A total of 131 patients (mean age 25) underwent MRE, 60 of whom had been previously diagnosed with CD and 17 with UC. Additionally, 26 patients with suspected IBD and 28 with other or unknown pathologies were included in the study. Radiological reports of MRE examinations, effectuated using a 1.5-T field strength, were retrospectively analysed regarding radiological features of IBD, such as the following: bowel wall thickening, enhancement, comb sign, stricture, enlarged mesenteric nodes, inflammatory infiltration, and abnormal diffusion restriction in diffusion-weighted imaging. The statistical model was based on machine learning of the Kohonen map, together with univariate and multivariate analysis. RESULTS: The selected neuron (Neuron 3) incorporated 23 cases of CD, 9 of suspected IBD, 2 patients with UC, and 4 with other pathologies. The statistical analysis identified bowel wall thickening, intestinal stricture, and lymphadenopathy as the 3 MRE findings most associated with Neuron 3 (AUC = 0.919, p = 0.031). CONCLUSIONS: Bowel wall thickening, stricture, and enlarged mesenteric lymph nodes in MRE are independent predictive factors for CD diagnosis; thus, patients presenting these features should undergo further examinations. MRE constitutes a powerful imaging modality in cases of suspected IBD.

Supplementary Anal Imaging by Magnetic Resonance Enterography in Patients with Crohn's Disease Not Suspected of Having Perianal Fistulas.

BACKGROUND & AIMS: Few data are available to guide the use of anal imaging for patients with Crohn's disease (CD) who are not suspected of having perianal fistulas. We aimed to evaluate the role of anal imaging supplementary to magnetic resonance enterography (MRE) in these patients. METHODS: In a prospective study, we added a round of anal MR imaging (MRI), collecting axial images alone, to MRE evaluation of 451 consecutive adults who were diagnosed with or suspected of having CD but not believed to have perianal fistulas. Images were examined for perianal tracts; if present, colorectal surgeons reexamined patients to identify external openings or perianal inflammation or abscess. Patients were followed and data were collected on dedicated treatment for perianal fistulas or abscess. We calculated the diagnostic yield for anal MRI, associated factors, and outcomes of MRI-detected asymptomatic perianal tracts. RESULTS: A total of 440 patients (mean age, 29.6±8.9 years) met the inclusion criteria. Anal MRI revealed perianal tracts in 53 patients (12%; 95% CI, 9.3%-15.4%). Surgeons however did not identify any lesions that required treatment. The asymptomatic tracts were mostly single unbranched (83%), inter-sphincteric (72%), or had a linear dark signal at the tract margin (79%). Younger age at MRE, female sex, and CD activity index scores of 220-450 were independently associated with detection of perianal tracts. MRI detection of asymptomatic tracts was independently associated with later development of perianal fistulas or abscess that required treatment: 17.8% cumulative incidence at 37 months and an adjusted hazard ratio of 3.06 (95% CI, 1.01-9.27; P = .048). CONCLUSIONS: In a prospective study of patients with CD, we found that adding anal MRI evaluation to MRE resulted in early identification of patients at risk for perianal complications.

Magnetic resonance enterography perfusion parameters reveal complex changes in affected and unaffected segments in Crohn's disease.

OBJECTIVES: To compare dynamic contrast-enhanced (DCE)-MRI parameters in affected and unaffected segments of CD patients with those of a control group, and to assess the correlation between DCE-MRI parameters and clinical index of activity (HBI) as well as biomarkers (CRP and faecal calprotectin). METHODS: We performed a single-center prospective study of CD patients and control subjects who underwent DCE-MRI. Regions of interest were drawn in segments and the program (Olea Medical - Canon) provided values for transfer constant (Ktrans), fractional volume of extravascular-extracellular space (Ve), slope of enhancement (SoE), time to maximum enhancement (TME), maximum enhancement (ME) and enhancement ratio (ER) which were determined and compared. RESULTS: Fifteen CD patients (mean age 42 years; 10 women) and 7 healthy subjects (mean age 40.4 years; 6 women) were included. Paired comparisons of affected and unaffected segments in CD showed a significant increase of all parameters in affected segments, except for ER and TME. When comparing to controls, the affected segments did not show any significant difference, while a significant decrease in most of the parameters (except for ER and TME) was observed when comparing unaffected segments of CD patients to controls. In CD, significant correlations between DCE-MRI parameters and biomarkers (CRP, faecal calprotectin) were more frequent in unaffected segments than in affected segments. CONCLUSIONS: Significant differences in perfusion parameters were observed between affected and unaffected segments of CD patients and between unaffected segments and those of control subjects. This suggests complex perfusion changes in both unaffected and affected intestinal segments in CD.

Magnetic resonance enterography for predicting the clinical course of Crohn's disease strictures.

BACKGROUND AND AIMS: Strictures are the most common Crohn's disease complication, but their natural history is unknown. This study aimed to characterize inflammation, predict prognosis, and understand the impact of drug therapy using magnetic resonance enterography (MRE). METHODS: Patients with a stricture diagnosed on MRE over a 5-year period were reviewed for MRE disease extent and inflammation, clinical course, C-reactive protein, response to anti-TNF therapy, endoscopic dilatation, hospitalization, and surgery. RESULTS: 136 patients had 235 strictures (77, one and 59, ≥ 2 strictures). TREATMENT: 46% of patients underwent surgery after a median 6 months; median follow-up for those not requiring surgery was 41 months. Predictors of surgery: Hospitalization because of obstruction predicted subsequent surgery (OR 2.50; 95% CI 1.06-5.90) while anti-TNF therapy commenced at stricture diagnosis was associated with a reduced risk (OR 0.23; 95% CI 0.05-0.99). MRE characteristics associated with surgery were proximal bowel dilatation ≥ 30-mm diameter (OR 2.98; 95% CI 1.36-6.55), stricture bowel wall thickness ≥ 10-mm (OR 2.42; 95% CI 1.11-5.27), and stricture length > 5-cm (OR 2.56; 95% CI 1.21-5.43). 81% of patients with these three adverse MRE features required surgery versus 17% if none were present (P < 0.001). Accuracy for these three MRE variables predicting surgery was high (AUC 0.76). CONCLUSION: Magnetic resonance enterography findings in Crohn's disease strictures are highly predictive of the disease course and the need for future surgery. MRE may also identify who would benefit from treatment intensification. Anti-TNF therapy is associated with reduced risk of surgery and appears to alter the natural history of this complication.

Radiological Response Is Associated with Better Outcomes and Should Be Considered a Therapeutic Target in Crohn's Disease.

BACKGROUND: The aim of the study was to identify factors associated with a radiological response and to assess the impact of radiological improvement in long-term outcomes in small bowel (SB) Crohn's disease (CD) patients. METHODS: We performed a retrospective study from June 2011 to June 2017 in the tertiary center, Claude Huriez Hospital in Lille, France. All SB CD patients, who underwent two magnetic resonance enterographies (MRE) 3-12 months apart, with at least 1-year follow-up after the second MRE, were included. Signs of radiological inflammation were identified by two expert radiologists in CD. Patients were classified as radiological responders (RR) and non-responders (NR). Hospitalization rates, adjustment of treatment, and surgical or endoscopic interventions were assessed and compared between RR and NR. Factors associated with a radiological response were also studied using the Cox model. RESULTS: One hundred and fifteen SB CD patients were included with a median follow-up of 17 months (IQR 11.6-28.3). There were 54 (47%) RR and 61 (53%) NR. The risk of surgical or endoscopic intervention was higher in NR than RR (p = 0.04), and the median delay until a surgical or endoscopic intervention was shorter in NR (p = 0.04). Multifocal disease, a hypersignal on diffusion-weighted or dynamic contrast-enhanced imaging, a stricture, or a fistula was significantly associated with a decreased probability of a radiological response (p < 0.05). CONCLUSION: This study shows that a radiological response is associated with a decreased risk of surgical or endoscopic intervention and should be considered as a therapeutic target in CD patients.

Usefulness of magnetic resonance enterography in the clinical decision-making process for patients with inflammatory bowel disease.

OBJECTIVE: To evaluate the impact of magnetic resonance enterography (MRE) diagnosis on clinical decision-making regarding treatment choice and maintenance of treatment over time in patients with inflammatory bowel disease (IBD). METHODS: A cohort of patients who underwent MRE for IBD assessment between 2011 and 2014 was analyzed. From clinical records, we retrospectively retrieved their demographic data and clinical data on their IBD at the time of MRE, the results of MRE and the patient's clinical course. Medical management decisions made during the three months following MRE and at the 15-month follow-up were assessed. RESULTS: In total, 474 MREs were reviewed. In the first three-month period, MRE results led to changes in the medical management of 266 patients (56.1%). Of those, maintenance therapy was altered in 140 patients (68.3%) (90.7% step-up and 9.3% top-down strategy), 65 (24.4%) were prescribed a course of steroids and 61 (22.9%) underwent surgery. MRE confirmed a CD diagnosis in 14/41 patients (34.1%) previously diagnosed with indeterminate colitis or ulcerative colitis and in 4/18 patients (22.2%) with suspected IBD. At the 15-month follow-up, treatment remained unchanged in 289 patients (65.8%). CONCLUSIONS: These results suggest that MRE is a diagnostic tool that provides valid information for the clinical-decision making process for patients with CD.