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Intestinal fibrosis is the primary cause of disability in patients with Crohn's disease (CD), yet effective therapeutic strategies are currently lacking. Here, we report a multiomics analysis of gut microbiota and fecal/blood metabolites of 278 CD patients and 28 healthy controls, identifying characteristic alterations in gut microbiota (e.g., Lachnospiraceae, Ruminococcaceae, Muribaculaceae, Saccharimonadales) and metabolites (e.g., L-aspartic acid, glutamine, ethylmethylacetic acid) in moderate-severe intestinal fibrosis. By integrating multiomics data with magnetic resonance enterography features, putative links between microbial metabolites and intestinal fibrosis-associated morphological alterations were established. These potential associations were mediated by specific combinations of amino acids (e.g., L-aspartic acid), primary bile acids, and glutamine. Finally, we provided causal evidence that L-aspartic acid aggravated intestinal fibrosis both in vitro and in vivo. Overall, we offer a biologically plausible explanation for the hypothesis that gut microbiota and its metabolites promote intestinal fibrosis in CD while also identifying potential targets for therapeutic trials. Synopsis: The gut microbiota and its functional metabolites play crucial roles in the development of intestinal fibrosis in patients with Crohn's disease (CD). The severity of intestinal fibrosis was associated with alterations in the gut microbiota (e.g., Lachnospiraceae) and the fecal and blood metabolites (e.g., L-aspartic acid). Specific microbes and their metabolites were associated with fibrosis-related luminal and extraluminal morphological alterations (i.e., stricture, penetration, effusion and comb sign). L-aspartic acid, identified as a potential target, promoted the progression of intestinal fibrosis in vitro and in vivo. A machine learning-based classifier had been developed based on the combination of 11 microbial and metabolic predictors for distinguishing the severity of intestinal fibrosis in patients with CD. The gut microbiota and its functional metabolites play crucial roles in the development of intestinal fibrosis in patients with Crohn's disease (CD). [ABSTRACT FROM AUTHOR]

Magnetic resonance enterography [MRE] and intestinal ultrasound [IUS] have developed rapidly in the past few decades, emerging as the primary non-invasive options for both diagnosing and monitoring Crohn's disease [CD]. In this review, we evaluate the pertinent data relating to the use of MRE and IUS in CD. We summarise the key imaging features of CD activity, highlight their increasing role in both the clinical and the research settings, and discuss how these modalities fit within the diagnostic pathway. We discuss how they can be used to assess disease activity and treatment responsiveness, including the emergence of activity scores for standardised reporting. Additionally, we address areas of controversy such as the use of contrast agents, the role of diffusion-weighted imaging, and point-of-care ultrasound. We also highlight exciting new developments, including the applications of artificial intelligence. Finally, we provide suggestions for future research priorities. [ABSTRACT FROM AUTHOR]

Abstract Intestinal fibrosis is the primary cause of disability in patients with Crohn’s disease (CD), yet effective therapeutic strategies are currently lacking. Here, we report a multiomics analysis of gut microbiota and fecal/blood metabolites of 278 CD patients and 28 healthy controls, identifying characteristic alterations in gut microbiota (e.g., Lachnospiraceae, Ruminococcaceae, Muribaculaceae, Saccharimonadales) and metabolites (e.g., L-aspartic acid, glutamine, ethylmethylacetic acid) in moderate-severe intestinal fibrosis. By integrating multiomics data with magnetic resonance enterography features, putative links between microbial metabolites and intestinal fibrosis-associated morphological alterations were established. These potential associations were mediated by specific combinations of amino acids (e.g., L-aspartic acid), primary bile acids, and glutamine. Finally, we provided causal evidence that L-aspartic acid aggravated intestinal fibrosis both in vitro and in vivo. Overall, we offer a biologically plausible explanation for the hypothesis that gut microbiota and its metabolites promote intestinal fibrosis in CD while also identifying potential targets for therapeutic trials.

Abstract Background Crohn’s disease is a chronic inflammatory bowel disease that can affect any part of the gut. Endoscopy is the gold standard for diagnosis, but it only assesses mucosal lesions. Magnetic resonance enterography (MRE) can assess disease presence and activity, but it has limitations such as motion sensitivity, long scan time, and high cost. Bowel sonography has been introduced as a non-invasive, practical, safe, and low-cost technique to assess disease activity and complications. In our study we aim to assess the comparability of ultrasound to MRE in evaluation of patients with Crohn’s disease, and its complications. Results Twenty-five patients with 38 Crohn’s disease affected segments were evaluated by bowel ultrasound (BUS) and MRI enterography (MRE), where BUS and MRE showed equivalent diagnostic performance for disease detection and localization (97.4%, 100%), for sensitivity and specificity of both modalities. Peri-mural fluid (89.5%, 94.4%) and mural stratification loss (100%, 100%) showed high sensitivity and specificity by BUS compared to MRE, while for assessment of mural vascularity, BUS showed high sensitivity and specificity for high grade vascularity (100%, 83.3%), but low sensitivity and high specificity for low and moderate vascularity (0%–62.5%, 81.8%) compared to MRE. Complications including fistulae and abscessed were all correctly identified in BUS compared to MRE. Conclusion BUS showed comparable results to MRE for identification, localization, assessment of findings related to disease activity, and complications in cases of Crohn’s disease rendering it a viable alternative to MRE.

Objectives: Differentiating intestinal tuberculosis (ITB) from Crohn's disease (CD) remains a diagnostic dilemma. Misdiagnosis carries potential grave implications. We aim to establish a multidisciplinary-based model using machine learning approach for distinguishing ITB from CD. Methods: Eighty-two patients including 25 patients with ITB and 57 patients with CD were retrospectively recruited (54 in training cohort and 28 in testing cohort). The region of interest (ROI) for the lesion was delineated on magnetic resonance enterography (MRE) and colonoscopy images. Radiomic features were extracted by least absolute shrinkage and selection operator regression. Pathological feature was extracted automatically by deep-learning method. Clinical features were filtered by logistic regression analysis. Diagnostic performance was evaluated by receiver operating characteristic (ROC) curve and decision curve analysis (DCA). Delong's test was applied to compare the efficiency between the multidisciplinary-based model and the other four single-disciplinary-based models. Results: The radiomics model based on MRE features yielded an AUC of 0.87 (95% confidence interval [CI] 0.68–0.96) on the test data set, which was similar to the clinical model (AUC, 0.90 [95% CI 0.71–0.98]) and higher than the colonoscopy radiomics model (AUC, 0.68 [95% CI 0.48–0.84]) and pathology deep-learning model (AUC, 0.70 [95% CI 0.49–0.85]). Multidisciplinary model, integrating 3 clinical, 21 MRE radiomic, 5 colonoscopy radiomic, and 4 pathology deep-learning features, could significantly improve the diagnostic performance (AUC of 0.94, 95% CI 0.78–1.00) on the bases of single-disciplinary-based models. DCA confirmed the clinical utility. Conclusions: Multidisciplinary-based model integrating clinical, MRE, colonoscopy, and pathology features was useful in distinguishing ITB from CD. [ABSTRACT FROM AUTHOR]

Background: Crohn's disease is a chronic inflammatory bowel disease that can affect any part of the gut. Endoscopy is the gold standard for diagnosis, but it only assesses mucosal lesions. Magnetic resonance enterography (MRE) can assess disease presence and activity, but it has limitations such as motion sensitivity, long scan time, and high cost. Bowel sonography has been introduced as a non-invasive, practical, safe, and low-cost technique to assess disease activity and complications. In our study we aim to assess the comparability of ultrasound to MRE in evaluation of patients with Crohn's disease, and its complications. Results: Twenty-five patients with 38 Crohn's disease affected segments were evaluated by bowel ultrasound (BUS) and MRI enterography (MRE), where BUS and MRE showed equivalent diagnostic performance for disease detection and localization (97.4%, 100%), for sensitivity and specificity of both modalities. Peri-mural fluid (89.5%, 94.4%) and mural stratification loss (100%, 100%) showed high sensitivity and specificity by BUS compared to MRE, while for assessment of mural vascularity, BUS showed high sensitivity and specificity for high grade vascularity (100%, 83.3%), but low sensitivity and high specificity for low and moderate vascularity (0%–62.5%, 81.8%) compared to MRE. Complications including fistulae and abscessed were all correctly identified in BUS compared to MRE. Conclusion: BUS showed comparable results to MRE for identification, localization, assessment of findings related to disease activity, and complications in cases of Crohn's disease rendering it a viable alternative to MRE. [ABSTRACT FROM AUTHOR]

Abstract Background Crohn’s disease (CD) is an inflammatory disease of the gastrointestinal tract. The disease behavior changes over time, and endoscopy is crucial in evaluating and monitoring the course of CD. To reduce the economic burden of patients and alleviate the discomfort associated with ineffective examination, it is necessary to fully understand the location, extent, and severity of intestinal stenosis in patients with CD before endoscopy. This study aimed to utilize imaging features of magnetic resonance enterography (MRE) to evaluate intestinal stenosis in patients with CD and to predict whether endoscopy could be passed. Methods MRE data of patients with CD were collected, while age, gender, disease duration, and laboratory test parameters were also gathered. Two radiologists analyzed the images and assessed whether endoscopy could be passed based on the imaging performance. Imaging features of MRE were analyzed in groups based on endoscopy results. Results The readers evaluated the imaging performance for 86 patients to determine if endoscopy could be passed and performed a consistency test (compared between two readers k = 0.812, p = 0.000). In the univariate analysis, statistical differences were observed in the degree of T1WI enhancement, thickness of the intestine wall at the stenosis, and diameter of the upstream intestine between the two groups of whether endoscopy was passed. In multivariate logistic regression, the diameter of the upstream intestine was identified to be an independent factor in predicting whether endoscopy was passed or not (OR = 3.260, p = 0.046). Conclusions The utilization of MRE signs for assessing the passage of an endoscope through the narrow segment revealed that the diameter of the upstream intestine emerged as an independent predictor of endoscopic passage. Before performing an endoscopy, MRE can aid in evaluating the passage of the endoscope. Critical relevance statement This retrospective study explored the imaging features of MRE to evaluate intestinal stenosis in patients with Crohn’s disease and determined that the diameter of the upstream intestine of the stenotic segment was an independent predictor in assessing endoscopic passage. Key points • Endoscopy is crucial in evaluating and monitoring the course of Crohn’s disease. • The diameter of the upstream intestine of the stenotic segment was an independent predictor in assessing endoscopic passage. • MRE can aid in evaluating the passage of the endoscope in stenotic segments of Crohn’s disease. Graphical Abstract

Objective To develop a nomogram for predicting the risks of early anastomotic recurrence (EAR) after primary bowel resection in patients with Crohn′s disease (CD). Methods The patients with CD undergoing preoperative magnetic resonance enterography (MRE) and primary bowel resection were enrolled in this retrospective study and divided into an EAR group (18 patients) and EAR-free group (12 patients). The EAR group included the patients having an endoscopic Rutgeerts score of ≥ I2 month or the need for anastomotic resection within 12 months after surgery. All the 38 indexes including preoperative demographic characteristics, laboratory examinations, multi-parameter MRE features of the resected intestine and its adjacent mesentery, histological findings, and postoperative pharmacotherapy were analyzed. Least absolute shrinkage and selection operator (LASSO) regression and multivariate binary logistic regression analysis were performed to identify independent risk factors to be incorporated into the nomogram for predicting the risks of early anastomotic recurrence and the prediction performance was evaluated. Results Mesenteric creeping fat index on MRE and comb sign were independent risks of EAR, with a concordance index of 0.882 (95%CI: 0.764~1). The calibration plot revealed a strong relationship between actual observation and predicted probability of EAR. Conclusions The preoperative MRE-based nomogram may be a potential tool for predicting EAR following surgery in patients with CD, which is beneficial to individual management in those patients. It provides reference for the formulation of early postoperative individualized drug adjuvant therapy in patients at high risk of EAR. [ABSTRACT FROM AUTHOR]

Jordi Rimola,1 Jean-Frédéric Colombel,2 Brian Bressler,3 Shashi Adsul,4 Jenifer Siegelman,5 Patricia E Cole,5 Dirk Lindner,4 Silvio Danese6 1IBD Unit, Radiology Department, Hospital Clínic de Barcelona, Barcelona, Spain; 2The Dr. Henry D. Janowitz Division of Gastroenterology, Icahn School of Medicine at Mount Sinai, New York, NY, USA; 3Division of Gastroenterology, University of British Columbia, Vancouver, BC, Canada; 4Takeda Pharmaceuticals International, Zurich, Switzerland; 5Takeda Pharmaceuticals International, Cambridge, MA, USA; 6Gastroenterology and Endoscopy, IRCCS Ospedale San Raffaele and University Vita-Salute San Raffaele, Milan, ItalyCorrespondence: Jordi Rimola, IBD Unit, Radiology Department, Hospital Clínic de Barcelona, Barcelona, Spain, Tel +34 932 275 400, Email jrimola@clinic.catPurpose: The VERSIFY phase 3 trial in patients with Crohn’s disease (CD) treated with vedolizumab was the first to include a substudy that used a standardized magnetic resonance enterography (MRE) protocol to assess features of transmural inflammation (bowel edema and wall thickness) and extramural disease activity (enlarged lymph nodes).Patients and Methods: Patients received intravenous vedolizumab (300 mg) at weeks 0 (baseline), 2, and 6, and then every 8 weeks for 26 or 52 weeks. Post hoc analyses included a subpopulation with a Magnetic Resonance Index of Activity score of ≥ 7 in at least one bowel segment at baseline and at least one postbaseline MRE assessment. Changes in transmural inflammation, including intramural bowel edema and wall thickness, were evaluated. Patient-level and segment-level analyses were performed.Results: MRE images were evaluated in 27 patients with 83 evaluable bowel segments at baseline and week 26, and 13 patients with 38 evaluable segments at baseline, week 26, and week 52. At baseline, all patients had bowel wall edema and wall thickness of > 3 mm in at least one bowel segment. The proportion of patients with edema decreased at weeks 26 (17/27 [63.0%]) and 52 (4/13 [30.8%]) and the proportion with bowel wall thickness of > 3 mm decreased at weeks 26 (25/27 [92.6%]) and 52 (10/13 [76.9%]).Conclusion: In patients with CD treated with vedolizumab for 26 and 52 weeks, the number of patients, and bowel segments, with MRE-detected transmural inflammation was reduced. These results highlight the impact of vedolizumab on components of transmural inflammation in CD and demonstrate that using MRE in CD multicenter clinical trials is feasible.Trial Registration: ClinicalTrials.gov NCT02425111, April 23, 2015, http://www.clinicaltrials.gov NCT02425111; EU Clinical Trials Register EudraCT 2014– 003509-13, https://www.clinicaltrialsregister.eu. Keywords: vedolizumab, magnetic resonance enterography, Crohn’s disease, clinical trials, imaging

Background/Aims: Inflammatory bowel diseases (IBD) are of two types: Crohn’s disease (CD) and ulcerative colitis (UC). The differential diagnosis of these two diseases is important because their treatment strategies are different. The present study aimed to evaluate the Magnetic Resonance Enterography (MRE) findings of pediatric patients who were clinically diagnosed with CD or UC. Material and Method: The patients under the age of 18, who underwent MRE examination, were retrospectively screened. Fifty five of those patients, who were clinically diagnosed with CD or UC, were included in the study. Bowel wall thickening, mesenteric fat tissue changes and complications were evaluated, and the findings were recorded. The sensitivity and specificity of MRE in the diagnosis of CD and UC in IBD patients were calculated. Results: Three of the patients clinically diagnosed with CD (7.3%) and six patients who had UC (42.9%) had involvement from the rectum to the proximal colonic segments (continuous lesions). Of those diagnosed with CD, 11 (26.8%) had skip lesions. In patients with IBD, the sensitivity of MRE for the diagnosis of CD was 56.1% and the specifity was 100%. The sensitivity of MRE for the diagnosis of UC was 42.9% and the specificity was 90.2%. Conclusion: MRE is helpful to identify the signs and complications of inflammatory bowel diseases. Although MRE has low sensitivity to differentiate between CD or UC in pediatric patients, it may help with its high specificity rates.

Abstract Background Inflammatory bowel disease (IBD) is considered as significant cause of morbidity in children with a global rise in its pediatric onset recently. Our study aimed to assess the facility of magnetic resonance enterography (MRE) and diffusion-weighted imaging (DWI) to identify the activity of pediatric IBD in correlation with clinical and endoscopic activity scores. Twenty-four patients of IBD who underwent clinical examination, ileocolonoscopy and MRE and DWI within less than 14 days were prospectively included. For all Crohn’s cases (9/24), the simplified endoscopic activity score for Crohn’s disease (SES-CD) and magnetic resonance enterography global score (MEGS) were acquired, while for all UC (15/24) cases, MRE score and Mayo endoscopic score were calculated. Sensitivity and specificity of MRE for detection disease activity against clinical and endoscopic scores were compared. Pathological reference for disease activity was based on assessment for mucosal inflammatory changes on endoscopic biopsy in all cases. Results There was a perfect inter-observer agreement (kappa 0.81–1) regarding wall thickening and mural edema, with substantial agreement (kappa 0.61–0.8) for MRE severity score, mural diffusion restriction, mesenteric edema and vascular congestion, while mural enhancement and for number of active LNs revealed moderate agreement (kappa 0.41–0.6). There was a significant positive correlation between MEGS and SES-CD in Crohn’s cases as well as between Mayo endoscopic score and MRE severity in UC cases (r = 0.970, p > 0.001 and r = 0.544, p = 0.036, respectively). MRE compared to endoscopic findings and clinical activity scores revealed high accuracy (95.8%) with 87.5%, 80%, 96% and 94.1% for sensitivity, specificity, PPV and NPV, respectively. Conclusion MR enterography is a noninvasive reliable imaging modality of high accuracy for the diagnosis of pediatric IBD severity compared to endoscopic activity scores and pathological severity.

Background: The goal of this study was to evaluate magnetic resonance enterography (MRE) findings and assess the role of diffusion-weighted imaging (DWI) in patients suffering from active Crohn's disease. Methods: This retrospective study included a total number of 76 patients diagnosed with active Crohn's disease, as established by the Crohn's Disease Activity Index (CDAI). The study consisted of 30 women and 46 men, ranging in age from 13 to 72 years. All participants underwent MRE with DWI sequences. The study was conducted at Imam Khomeini hospital in Tehran between 2013 and 2018. The imaging modality utilized for the study included a 3-T SIGNA Excite MRE machine and a Siemens Magnetom 3-T magnetic resonance imaging (MRI) machine. Results: Bowel wall restriction was observed in less than half of the patients, and no significant correlation was found with extramural findings such as mesenteric edema. The study did not reveal any meaningful association between diffusion restriction and specific mural enhancement patterns, mesenteric lymphadenopathy with or without enhancement, or the length of the affected segments (P > 0.05). The most common findings observed in MRI were ileum thickness in 72.4% of patients, mesenteric lymphadenopathy without enhancement in 46.1%, ileocecal thickness in 42.1%, DWI findings in 42.1%, the presence of a comb sign in 36.8%, and jejunum thickness in 30.3% of patients. Conclusion: MRE findings are useful in the evaluation of Crohn's disease activity. [ABSTRACT FROM AUTHOR]

Background Magnetic resonance imaging is increasingly used to assess treatment response in Crohn's disease clinical trials. We aimed to describe the definition of MRI response and remission as assessed by magnetic resonance enterography [MRE] to evaluate treatment efficacy in these patients. Methods Electronic databases were searched up to May 1, 2023. All published studies enrolling patients with inflammatory bowel disease and assessment of treatment efficacy with MRE were eligible for inclusion. Results Eighteen studies were included. All studies were performed in patients with Crohn's disease. The study period ranged from 2008 to 2023. The majority of studies used endoscopy as the reference standard [61.1%]. MRE response was defined in 11 studies [61.1%]. Five scores and nine different definitions were proposed for MRE response. MRE remission was defined in 12 studies [66.7%]. Three scores and nine different definitions for MRE remission were described. The MaRIA score was the most frequent index used to evaluate MRE response [63.6%] and remission [41.7%]. MRE response was defined as MaRIA score <11 in 63.6% of studies using this index. In 60% of studies using the MaRIA score, MRE remission was defined as MaRIA score <7. In addition, 11 different time points of assessment were reported, ranging from 6 weeks to years. Conclusion In this systematic review, significant heterogeneity in the definition of MRE response and remission evaluated in patients with Crohn's disease was observed. Harmonization of eligibility and outcome criteria for MRE in Crohn's Disease clinical trials is needed. [ABSTRACT FROM AUTHOR]

The diagnosis of Crohn's Disease (CD) is based on a combination of clinical symptoms, laboratory tests, endoscopy, and imaging data. In Small Intestine Contrast Ultrasonography (SICUS), the ingestion of a macrogol solution as an oral contrast medium may optimize image quality. We performed a meta-analysis to evaluate the diagnostic performance of SICUS for CD. A literature search was performed in August 2023. We selected only studies where SICUS was compared to a technique that allows the assessment of the whole gastrointestinal tract, such as an MRE, a CT scan, or a surgical evaluation. We estimated pooled weighted sensitivity, specificity, and likelihood ratio for positive and negative tests (PLR/NLR) of SICUS. Summary receiver operating characteristic curves (SROC) were drawn, and pooled areas under the curve (AUC) were calculated. Five studies with 325 CD patients were included. SICUS showed a pooled sensitivity for the diagnosis of 95% (95% confidence interval CI 89–99%), a specificity = 77% (95% CI 60–90%), and the AUC was 0.94. SICUS demonstrated a pooled sensitivity for strictures of 78% (95% CI 63–88%) and a specificity = 96% (95% CI 85–99%), with AUC = 0.93. For abscesses, SICUS demonstrated a pooled sensitivity of 100% (95% CI 59–100%) and a specificity of 90% (95% CI 74–98%). Fistulae were detected with a pooled sensitivity of 77% (95% CI 46–95%) and a specificity of 92% (95% CI 75–99%). SICUS demonstrated excellent diagnostic performance compared to the gold standard despite some clinical scenarios (stenosis/fistulae) showing suboptimal diagnostic effectiveness. [ABSTRACT FROM AUTHOR]

Background/Aıms: Inflammatory bowel diseases (IBD) are of two types: Crohn's disease (CD) and ulcerative colitis (UC). The differential diagnosis of these two diseases is important because their treatment strategies are different. The present study aimed to evaluate the Magnetic Resonance Enterography (MRE) findings of pediatric patients who were clinically diagnosed with CD or UC. Materıal And Method: The patients under the age of 18, who underwent MRE examination, were retrospectively screened. Fifty five of those patients, who were clinically diagnosed with CD or UC, were included in the study. Bowel wall thickening, mesenteric fat tissue changes and complications were evaluated, and the findings were recorded. The sensitivity and specificity of MRE in the diagnosis of CD and UC in IBD patients were calculated. Results: Three of the patients clinically diagnosed with CD (7.3%) and six patients who had UC (42.9%) had involvement from the rectum to the proximal colonic segments (continuous lesions). Of those diagnosed with CD, 11 (26.8%) had skip lesions. In patients with IBD, the sensitivity of MRE for the diagnosis of CD was 56.1% and the specifity was 100%. The sensitivity of MRE for the diagnosis of UC was 42.9% and the specificity was 90.2%. Conclusıon: MRE is helpful to identify the signs and complications of inflammatory bowel diseases. Although MRE has low sensitivity to differentiate between CD or UC in pediatric patients, it may help with its high specificity rates. [ABSTRACT FROM AUTHOR]

Background: Inflammatory bowel disease (IBD) is considered as significant cause of morbidity in children with a global rise in its pediatric onset recently. Our study aimed to assess the facility of magnetic resonance enterography (MRE) and diffusion-weighted imaging (DWI) to identify the activity of pediatric IBD in correlation with clinical and endoscopic activity scores. Twenty-four patients of IBD who underwent clinical examination, ileocolonoscopy and MRE and DWI within less than 14 days were prospectively included. For all Crohn's cases (9/24), the simplified endoscopic activity score for Crohn's disease (SES-CD) and magnetic resonance enterography global score (MEGS) were acquired, while for all UC (15/24) cases, MRE score and Mayo endoscopic score were calculated. Sensitivity and specificity of MRE for detection disease activity against clinical and endoscopic scores were compared. Pathological reference for disease activity was based on assessment for mucosal inflammatory changes on endoscopic biopsy in all cases. Results: There was a perfect inter-observer agreement (kappa 0.81–1) regarding wall thickening and mural edema, with substantial agreement (kappa 0.61–0.8) for MRE severity score, mural diffusion restriction, mesenteric edema and vascular congestion, while mural enhancement and for number of active LNs revealed moderate agreement (kappa 0.41–0.6). There was a significant positive correlation between MEGS and SES-CD in Crohn's cases as well as between Mayo endoscopic score and MRE severity in UC cases (r = 0.970, p > 0.001 and r = 0.544, p = 0.036, respectively). MRE compared to endoscopic findings and clinical activity scores revealed high accuracy (95.8%) with 87.5%, 80%, 96% and 94.1% for sensitivity, specificity, PPV and NPV, respectively. Conclusion: MR enterography is a noninvasive reliable imaging modality of high accuracy for the diagnosis of pediatric IBD severity compared to endoscopic activity scores and pathological severity. [ABSTRACT FROM AUTHOR]

The large bowel can be affected by inflammatory bowel diseases, namely ulcerative colitis and Crohn's disease, with the latter occurring either as a unique localization or in conjunction with simultaneous ileal involvement. The differential diagnosis among these conditions is challenging and relies on clinical symptoms, laboratory tests and endoscopy with biopsy. However, as these features can overlap, a conclusive diagnosis is not always achievable, and the underlying cause remains indeterminate. Currently, endoscopy is the reference standard for colonic assessment, although its invasiveness limits its use and repetition within a short timeframe. Magnetic Resonance Enterography is a non-invasive, radiation-free technique that has been extensively and effectively employed in the intestinal evaluation of patients with Crohn's disease in recent years. Although the main goal of this technique is generally focused on evaluating small bowel loops, it can also provide important information about the large bowel if an adequate fulfillment by the oral contrast medium is achieved. The purpose of this work is, therefore, to put emphasis on the potential role of Magnetic Resonance Enterography in assessing the large bowel. In fact, this imaging modality is capable of providing valuable information for comprehensive staging and follow-up of inflammatory bowel diseases within the large bowel, thus complementing the clinical picture and the endoscopic features in the context of a differential diagnosis. [ABSTRACT FROM AUTHOR]

IgA vasculitis (IgAV) is a small vessel vasculitis affecting children and, less commonly, adults; in the latter, gastro-intestinal (GI) involvement occurs in up to 50% of cases. Diagnosis is made with computed tomography, ultrasonography and endoscopy, but no data have been to date published about the use of magnetic resonance enterography (MRE). This work reports two leading cases of adult-onset IgAV with GI involvement in which MRE was used at baseline and during follow-up. The first case was for a 55-year old male presenting with microhematuria and elevated markers of inflammation at admission. MRE evidenced jejunum and proximal ileum diffuse and asymmetric thickening and hypervascularization. Leukocytoclastic vasculitis and glomerulonephritis with IgA deposit were evidenced at skin and renal biopsy, respectively. At one-year follow-up, a relapse was suspected: microhematuria and proteinuria were found at routine urinalysis, while MRE findings were similar to the ones at baseline. The second case was for a 49-year old male previously treated with methotrexate for mild seronegative arthritis, reporting hematochezia and worsening of arthralgias. Inflammatory bowel disease (IBD) was suspected and colonoscopy revealed diffuse mucosal hyperemia. Computerized tomography of the terminal ileum appeared thickened and edematous, while skin biopsy showed leukocytoclastic vasculitis with IgA infiltrate. The patient was successfully treated with oral prednisone and, after two months from discharge, MRE was negative. IgAV may occur in adults and presenting with GI involvement may be particularly severe, mimicking IBD. MRE is a promising tool in diagnosing and monitoring IgAV. [ABSTRACT FROM AUTHOR]

BackgroundTransmural healing (TH) is associated with better long-term outcomes in Crohn disease (CD), whereas pretreatment ileal gene signatures encoding myeloid inflammatory responses and extracellular matrix production are associated with stricturing. We aimed to develop a predictive model for ileal TH and to identify ileal genes and microbes associated with baseline luminal narrowing (LN), a precursor to strictures.Materials and methodsBaseline small bowel imaging obtained in the RISK pediatric CD cohort study was graded for LN. Ileal gene expression was determined by RNASeq, and the ileal microbial community composition was characterized using 16S rRNA amplicon sequencing. Clinical, demographic, radiologic, and genomic variables were tested for association with baseline LN and future TH.ResultsAfter controlling for ileal location, baseline ileal LN (odds ratio [OR], 0.3; 95% confidence interval [CI], 0.1-0.8), increasing serum albumin (OR, 4; 95% CI, 1.3-12.3), and anti-Saccharomyces cerevisiae antibodies IgG serology (OR, 0.97; 95% CI, 0.95-1) were associated with subsequent TH. A multivariable regression model including these factors had excellent discriminant power for TH (area under the curve, 0.86; positive predictive value, 80%; negative predictive value, 87%). Patients with baseline LN exhibited increased Enterobacteriaceae and inflammatory and extracellular matrix gene signatures, coupled with reduced levels of butyrate-producing commensals and a respiratory electron transport gene signature. Taxa including Lachnospiraceae and the genus Roseburia were associated with increased respiratory and decreased inflammatory gene signatures, and Aggregatibacter and Blautia bacteria were associated with reduced extracellular matrix gene expression.ConclusionsPediatric patients with CD with LN at diagnosis are less likely to achieve TH. The association between specific microbiota, wound healing gene programs, and LN may suggest future therapeutic targets.

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. [ABSTRACT FROM AUTHOR]

Intestinal ultrasound (IUS) is a patient-centric, noninvasive, real-time, point-of-care tool with the capability to aid in diagnosis and monitoring of disease activity in both Crohn's disease and ulcerative colitis without the need for bowel preparation. IUS can be used as a tool for precision monitoring of inflammatory bowel disease (IBD) treatment response. IUS as a cross-sectional imaging tool is as accurate as magnetic resonance enterography (MRE) for assessing the ileum and is more accurate than MRE for colonic assessment proximal to the rectum. Multiple simple ultrasound-based scoring systems have been internally validated with endoscopy in both Crohn's disease and ulcerative colitis, and changes in IUS parameters can be seen as early as 2 weeks after treatment initiation. IUS also plays a unique role in IBD activity monitoring of patients in whom avoidance of invasive testing is paramount, such as children and pregnant patients. Novel uses go beyond monitoring activity, with potential use of elastography to measure bowel wall stiffness to detect fibrosis and bowel damage for enhanced decision-making. Ultimately, IUS is likely to expand in the United States, facilitated by accessible expert training, access to equipment, and the development of a reimbursement model. This article provides a comprehensive review of the current and novel uses of IUS in IBD. [ABSTRACT FROM AUTHOR]

Introduction: It is well known that infliximab (IFX) trough levels (TLs) are associated with endoscopic healing (EH) in Crohn’s disease (CD). We investigated whether IFX TLs are associated with transmural healing (TH) in pediatric patients with CD following 1-year treatment. Methods: Pediatric patients with CD treated with IFX were included in this singlecenter prospective study. IFX TL tests, magnetic resonance enterography (MRE), and colonoscopies were simultaneously conducted after 1-year IFX treatment. TH was defined as a wall thickness of ≤3 mm without inflammatory signs evaluated using MRE. EH was defined as a Simple Endoscopic Score for Crohn’s disease of <3 points on colonoscopy. Results: Fifty-six patients were included. EH and TH were observed in 60.7% (34/ 56) and 23.2% (13/56) of patients, respectively. IFX TLs were higher in patients with EH (median, 5.6 vs. 3.4 µg/mL, P = 0.002), whereas IFX TLs showed no significant difference in patients with and without TH (median, 5.4 vs. 4.7 µg/mL, P = 0.574). No significant difference was observed in EH and TH between patients whose intervals were shortened or not. Multivariate logistic regression analysis showed that IFX TLs and disease duration to IFX initiation were associated with EH (odds ratio [OR] = 1.82, P = 0.001, and OR = 0.43, P = 0.02, respectively). Discussion: In pediatric patients with CD, IFX TLs were associated with EH but not with TH. Further studies investigating long-term TH and proactive dosing based on therapeutic drug monitoring may clarify whether an association between IFX TLs and TH exists. [ABSTRACT FROM AUTHOR]

Background: Transmural healing (TH) is a potential therapeutic goal of Crohn's disease (CD) and is associated with better clinical outcomes. However, few studies have described early TH and its predictors. Objectives: We aimed to evaluate early TH and its predictors using magnetic resonance enterography (MRE) in patients with CD receiving ustekinumab (UST). Design: This was a retrospective observational study. Methods: Patients with active CD treated with UST and their intestinal segments with bowel wall thickness (BWT) ⩽ 3 mm at baseline were included. Clinical characteristics, laboratory indicators, endoscopic manifestations, and MRE indices were evaluated at baseline and week 26 (W26) of the therapy. The following MRE parameters were assessed: BWT, edema, apparent diffusion coefficient (ADC), Clermont score, Magnetic Resonance Index of Activity score, fat stranding, comb sign, and stricture. TH was defined as BWT ⩽ 3 mm without any signs of inflammation (i.e., ulceration, edema, diffusion-weighted hyperintensity, and increased contrast enhancement) at W26. Results: The study included 37 patients with 106 intestinal segments (including 15 proximal small intestines, 33 terminal ilea, and 58 colons). Clinical features, laboratory indicators, endoscopic results, and MRE parameters at W26 were significantly improved after UST treatment in both patient-based and intestinal segment-based analysis. Seven (18.9%) patients and 26 (24.5%) intestinal segments achieved TH at W26. Baseline BWT [odds ratio (OR) = 0.287, 95% confidence interval (CI), 0.090–0.918, p = 0.035] and ADC (OR = 2.997, 95% CI, 1.009–8.908, p = 0.048) predict TH of patients at W26. Baseline ADC (OR = 2.857, 95% CI, 1.285–6.349, p = 0.010) and presence of stenosis (OR = 0.196, 95% CI, 0.052–0.735, p = 0.016) were associated with TH of segments at W26. Conclusion: Early TH assessed by MRE was observed in nearly one-fifth of patients with CD and intestinal segments after UST treatment for 26 weeks. Baseline MRE indices such as BWT and presence of stenosis might negatively predict TH, while ADC might positively predict early TH. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction. Ileal leiomyosarcoma is unusual form of malignant gastrointestinal tumor. Often insidious in clinical presentation, it frequently presents a diagnostic challenge. Occasionally, a correct diagnosis is finally established due to an emergency situation. The aim of this study was to present the role of magnetic enterography in determining the precise cause of small bowel dilation. Case outline. A 59-year-old female patient presented with small bowel obstruction. Erect abdominal radiograph identified the presence of small bowel obstruction and excluded pneumoperitoneum. A non-contrast computed tomography of the abdomen and pelvis noted transitional zone in the region of terminal ileum with collapsed bowel lumen distal to the transitional point, without determined underlying cause. Magnetic resonance enterography observed obstructive intraluminal soft-tissue mass with fatty component sized up to 4 cm in the terminal ileum, with mesenteric involvement. The abdominal surgeon revealed ileal intraluminal tumor which affected the locoregional mesentery and serosa of the adjacent bowel. Histological and immunohistochemical analysis confirmed the diagnosis of ileal leiomyosarcoma with involvement of wall serosa and mesenteric fat tissue. Conclusion. Magnetic resonance enterography is a reliable diagnostic tool for detection and diagnosis of malignant small bowel tumors. Sometimes, tumors manifest clinically as bowel obstruction. Surgical treatment is necessary, while histology and immunohistochemistry are crucial to confirm the diagnosis of small bowel leiomyosarcoma.

Abstract Background Inflammatory bowel disease (IBD) is widespread and rapidly rising in developing countries. It remains a significant issue in Western culture with a prevalence of more than 0.3%. Symptom control has been the only focus of treatment before the discovery that many individuals with IBD continue to have disease activity even in the absence of clinical symptoms. Therefore, treatment goals now include establishing clinical remission, steroid-free remission, and mucosal healing, which may eventually be complemented by transmural healing in cross-sectional imaging modalities. Magnetic resonance enterography (MRE), computed tomography enterography, and small-bowel ultrasound are now reliable methods for staging intramural lesions and extramural consequences in CD and for determining disease activity and severity. Recently literature suggests the incorporation of (MRE) for periodic reevaluation of IBD patients, as it offers small-bowel, colonic, and extra-enteric assessment as well as monitors the response to the anti-inflammatory therapy. The purpose of the current study was to compare MRE with ileo-colonoscopy findings in the diagnosis of IBD features, specifically Crohn's disease, and ulcerative colitis, as well as in the detection of disease exacerbation (Activity). Results This study used MRE and ileo-colonoscopy to assess chronic inflammatory bowel disease patients; the patient population (n = 30) was made up of (14/30, 46.7%) females and (16/30, 53.3%) males, with a mean age of 32 ± SD 13 years. MRE alone detected lymphadenopathy in 73.3% of patients, and mural thickening with a mean of 4.1 ± SD 5.1 mm. It has detected mucosal enhancement with 80% sensitivity and 60% specificity. However, it was unable to detect mucosal erosions or ulceration. Conclusions MRE is sensitive, inexpensive, noninvasive, and radiation-free for inflammatory bowel disease detection, with 86.7% diagnostic accuracy for affected areas. Unlike ileo-colonoscopy, it could examine the entire small intestine, precisely measure the affected loop, and detect activity signs such as mural thickening and lymphadenopathy. Only ileo-colonoscopy could detect mucosal degradation and superficial ulcers. IBD treatment protocols should incorporate MRE for small-bowel, colonic, and extra-enteric assessment, monitoring of disease activity, and anti-inflammatory therapy response.

Portal hypertension consists in an increased portal vein pressure due to prehepatic, hepatic, or posthepatic conditions, with cirrhosis representing the most common cause. The gastrointestinal tract can be secondarily affected not only with varices formation, whose rupture is one of the most dangerous complications, but also with small and large bowel involvement which can predispose to chronic intestinal bleeding. These conditions respectively take the name of portal hypertensive enteropathy and portal colonopathy and their assessment are of almost exclusive pertinence of endoscopic techniques. Up to now, only few reports have described this condition from the radiological point of view. Nevertheless, imaging modalities are not burdened by the invasiveness of endoscopic procedures and are also capable in providing useful information about the intestinal tract as well as the surrounding tissues. This is the first case reporting a diffuse involvement of the small bowel and the right colon in a patient suffering of portal hypertension due to cirrhosis evaluated through the performance of computed tomography and magnetic resonance enterography.

Chronic midgut malrotation is a rare condition found in the adult age that predisposes to severe complications. It derives from an incomplete rotation of the mesentery around the superior mesenteric artery during embryogenic development. This results in intestinal loops displacement and mesenteric malfixation. Nevertheless, other congenital abnormalities can be also associated, such as mesenteric cysts and biliopancreatic malformations. Imaging modalities employed in the evaluation of chronic midgut malrotation include contrast radiography, which permits to visualize the localization of the intestinal loops, and ultrasound, that can detect a twist of superior mesenteric vessels. Computed tomography is however considered the modality of choice, owing to its wide field of view and the rapid scan times. The role of magnetic resonance imaging in this field has been barely explored. In particular, magnetic resonance enterography has a consolidated role in the assessment of intestinal loops and allows detecting extra-intestinal findings as well. Moreover, the lack of radiation exposure makes this technique suitable for nonemergency cases, especially in young patients. This is the first description of simultaneous chronic midgut malrotation, mesenteric cyst and pancreas divisum discovered in a Crohn's disease patient. The performance of magnetic resonance enterography allowed to properly interpret this multifaceted clinical picture.

Abstract Diagnosis of intestinal vasculitis is often challenging due to the non-specific clinical and imaging findings. Vasculitides with gastrointestinal (GI) manifestations are rare, but their diagnosis holds immense significance as late or missed recognition can result in high mortality rates. Given the resemblance of radiologic findings with some other entities, GI vasculitis is often overlooked on small bowel studies done using computed tomography/magnetic resonance enterography (CTE/MRE). Hereon, we reviewed radiologic findings of vasculitis with gastrointestinal involvement on CTE and MRE. The variety of findings on MRE/CTE depend upon the size of the involved vessels. Signs of intestinal ischemia, e.g., mural thickening, submucosal edema, mural hyperenhancement, and restricted diffusion on diffusion-weighted imaging, are common in intestinal vasculitis. Involvement of the abdominal aorta and the major visceral arteries is presented as concentric mural thickening, transmural calcification, luminal stenosis, occlusion, aneurysmal changes, and collateral vessels. Such findings can be observed particularly in large- and medium-vessel vasculitis. The presence of extra-intestinal findings, including within the liver, kidneys, or spleen in the form of focal areas of infarction or heterogeneous enhancement due to microvascular involvement, can be another radiologic clue in diagnosis of vasculitis. The link between the clinical/laboratory findings and MRE/CTE abnormalities needs to be corresponded when it comes to the diagnosis of intestinal vasculitis.

Crohn's disease (CD) is a chronic immune mediated disorder that most commonly affects the small bowel and/or the large bowel. Treatment targets in CD include mucosal healing assessed via ileocolonoscopy and transmural healing assessed through cross-sectional imaging modalities such as magnetic resonance enterography (MRE). More recently, histological healing in CD has emerged as a treatment target, though it is made cumbersome given its reliance on frequent endoscopic examinations. With expert guidelines now recommending regular objective assessments as part of a treat-to-target approach, accurate non-invasive assessment will become increasingly critical. MRE has an established role in the assessment of small bowel CD, with growing data supportive of its ability in detecting disease activity at mucosal and histological levels. This could therefore potentially reduce the need for serial endoscopic assessment. Thus, this review will assess the capacity of individual MRE parameters and MRE indices for detecting mucosal and histological small bowel CD activity. Furthermore, challenging scenarios, such as CD activity detection in post-operative clinical scenarios and abnormal findings in the context of a normal ileocolonoscopy, will be explored. [ABSTRACT FROM AUTHOR]

Background: Crohn's disease (CD) is a chronic disorder that often starts at a young age and involves periods of remission and relapse. Prompt diagnosis of relapses through screening is crucial due to the potential morbid complications of untreated active inflammation. Magnetic resonance enterography (MRE) is a noninvasive technique to screen for active inflammation. The standard protocol involves intravenous injection of contrast agents with potential side effects. Some abbreviated non-contrast-enhanced MRE protocols are proposed as alternatives for conventional MRE to identify active inflammation. Currently, there is controversy regarding the applicability and accuracy of these protocols. This study aims to describe and compare these protocols and evaluate their accuracy in detecting active inflammation and CD complications. Methods: Results from a systematic search of three databases in August 2022 were queried and screened by abstract and full text. Eligible studies were qualitatively and quantitatively analyzed by diagnostic test accuracy meta-analysis. Results: 59 studies entered the systematic review, and 37 were eligible for meta-analysis. Diffusion-weighted imaging (DWI) and fast T2-weighted (T2w) sequences were most frequently used in abbreviated protocols and showed non-inferior accuracy compared to the full protocol in detecting active inflammation. ADC and qualitative DWI had pooled sensitivity of 90% (CI: 82–95%) and 89% (CI:82–93%) and pooled specificity of 94% (CI: 88–97%) and 89% (CI: 79–94%), respectively for detecting active inflammation. Moreover, T2w and combined T2w+DWI sequences had pooled sensitivity of 80% (CI: 64–90%) and 76% (CI: 61–86%) and pooled specificity of 90% (CI: 80–95%) and 87% (CI: 74 – 94%), respectively. Unenhanced protocols show relatively poor diagnostic accuracy in detecting penetrating complications of CD. Magnetization transfer imaging (MTI) has demonstrated excellent accuracy in detecting fibrosis. High heterogeneity was observed in all subgroups, and accuracy was reported to be highly operator dependent in most studies. Conclusion: An abbreviated protocol consisting of DWI and fast T2w imaging can potentially replace the full protocol MRE. Full protocol MRE will still have its role in identifying penetrating complications. MTI should be indicated in case of suspected fibrostenotic disease.

Background/Aims The optimal tools for monitoring Crohn’s disease (CD) are controversial. We compared radiology plus ileocolonoscopy and radiology alone in terms of prognosis prediction and evaluated the agreement between radiologic and ileocolonoscopic findings in patients with CD. Methods Patients with CD who were followed up with computed tomography enterography (CTE) or magnetic resonance enterography (MRE) alone or CTE or MRE plus ileocolonoscopy were retrospectively recruited. Time to relapse was investigated to evaluate the difference in prognosis using the log-rank and Cox regression tests, and the agreement between radiologic and ileocolonoscopic findings was determined using a kappa value. Results A total of 501 patients with CD in clinical remission who underwent CTE or MRE and/or ileocolonoscopy were analyzed. Of these, 372 (74.3%) patients underwent CTE or MRE alone and 129 (25.7%) patients underwent CTE or MRE plus ileocolonoscopy. The cumulative maintenance rate of clinical remission between the two groups was not significantly different (p = 0.526, log-rank test). In multivariate analysis, age

Background: Inflammatory bowel disease (IBD) is widespread and rapidly rising in developing countries. It remains a significant issue in Western culture with a prevalence of more than 0.3%. Symptom control has been the only focus of treatment before the discovery that many individuals with IBD continue to have disease activity even in the absence of clinical symptoms. Therefore, treatment goals now include establishing clinical remission, steroid-free remission, and mucosal healing, which may eventually be complemented by transmural healing in cross-sectional imaging modalities. Magnetic resonance enterography (MRE), computed tomography enterography, and small-bowel ultrasound are now reliable methods for staging intramural lesions and extramural consequences in CD and for determining disease activity and severity. Recently literature suggests the incorporation of (MRE) for periodic reevaluation of IBD patients, as it offers small-bowel, colonic, and extra-enteric assessment as well as monitors the response to the anti-inflammatory therapy. The purpose of the current study was to compare MRE with ileo-colonoscopy findings in the diagnosis of IBD features, specifically Crohn's disease, and ulcerative colitis, as well as in the detection of disease exacerbation (Activity). Results: This study used MRE and ileo-colonoscopy to assess chronic inflammatory bowel disease patients; the patient population (n = 30) was made up of (14/30, 46.7%) females and (16/30, 53.3%) males, with a mean age of 32 ± SD 13 years. MRE alone detected lymphadenopathy in 73.3% of patients, and mural thickening with a mean of 4.1 ± SD 5.1 mm. It has detected mucosal enhancement with 80% sensitivity and 60% specificity. However, it was unable to detect mucosal erosions or ulceration. Conclusions: MRE is sensitive, inexpensive, noninvasive, and radiation-free for inflammatory bowel disease detection, with 86.7% diagnostic accuracy for affected areas. Unlike ileo-colonoscopy, it could examine the entire small intestine, precisely measure the affected loop, and detect activity signs such as mural thickening and lymphadenopathy. Only ileo-colonoscopy could detect mucosal degradation and superficial ulcers. IBD treatment protocols should incorporate MRE for small-bowel, colonic, and extra-enteric assessment, monitoring of disease activity, and anti-inflammatory therapy response. [ABSTRACT FROM AUTHOR]

Background: Transmural healing (TH) is a potential therapeutic goal of Crohn’s disease (CD) and is associated with better clinical outcomes. However, few studies have described early TH and its predictors. Objectives: We aimed to evaluate early TH and its predictors using magnetic resonance enterography (MRE) in patients with CD receiving ustekinumab (UST). Design: This was a retrospective observational study. Methods: Patients with active CD treated with UST and their intestinal segments with bowel wall thickness (BWT) ⩽ 3 mm at baseline were included. Clinical characteristics, laboratory indicators, endoscopic manifestations, and MRE indices were evaluated at baseline and week 26 (W26) of the therapy. The following MRE parameters were assessed: BWT, edema, apparent diffusion coefficient (ADC), Clermont score, Magnetic Resonance Index of Activity score, fat stranding, comb sign, and stricture. TH was defined as BWT ⩽ 3 mm without any signs of inflammation (i.e., ulceration, edema, diffusion-weighted hyperintensity, and increased contrast enhancement) at W26. Results: The study included 37 patients with 106 intestinal segments (including 15 proximal small intestines, 33 terminal ilea, and 58 colons). Clinical features, laboratory indicators, endoscopic results, and MRE parameters at W26 were significantly improved after UST treatment in both patient-based and intestinal segment-based analysis. Seven (18.9%) patients and 26 (24.5%) intestinal segments achieved TH at W26. Baseline BWT [odds ratio (OR) = 0.287, 95% confidence interval (CI), 0.090-0.918, 푝 = 0.035] and ADC (OR = 2.997, 95% CI, 1.009-8.908, 푝 = 0.048) predict TH of patients at W26. Baseline ADC (OR = 2.857, 95% CI, 1.285- 6.349, 푝 = 0.010) and presence of stenosis (OR = 0.196, 95% CI, 0.052-0.735, 푝 = 0.016) were associated with TH of segments at W26. Conclusion: Early TH assessed by MRE was observed in nearly one-fifth of patients with CD and intestinal segments after UST treatment for 26 weeks. Baseline MRE indices such as BWT and presence of stenosis might negatively predict TH, while ADC might positively predict early TH. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Surgery remains an important treatment modality in the multidisciplinary management of patients with Crohn's disease (CD). To illustrate the recent advances in the management of postoperative CD we outline the contemporary approach to treatment: diagnosing disease recurrence using endoscopy or noninvasive methods and risk stratification underlying decisions to institute treatment. Endoscopic scoring indices are being refined to guide treatment decisions by accurately estimating the risk of recurrence based on endoscopic appearance. The original Rutgeerts score has been modified to separate anastomotic lesions from lesions in the neoterminal ileum. Two further indices, the REMIND score and the POCER index, were recently developed with the same intention. Noninvasive monitoring for recurrence using a method with high negative predictive value has the potential to simplify management algorithms and only perform ileocolonoscopy in a subset of patients. Fecal calprotectin, intestinal ultrasound, and magnetic resonance enterography are all being evaluated for this purpose. The use of infliximab for the prevention of postoperative recurrence is well supported by data, but management decisions are fraught with uncertainty for patients with previous exposure to biologics. Data on the use of ustekinumab and vedolizumab for postoperative CD are emerging, but controlled studies are lacking. [ABSTRACT FROM AUTHOR]

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. 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. 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). 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.) [Display omitted] We have developed a validated score, called the Pediatric Inflammatory Crohn's Magnetic Resonance Enterography Index, which quantifies the degree of inflammation in the bowel of children with Crohn's disease, as measured using magnetic resonance imaging of the bowel. [ABSTRACT FROM AUTHOR]

Small intestine lipomatosis is rare but may be associated with pain, intussusception, and gastrointestinal bleeding. In this report, we examine the case of a 41-year-old man who had recurrent presentations to the emergency department with non-specific abdominal pain. Preoperative imaging suggested extensive infiltration of small intestine with macroscopic fat. At surgery, extensive and confluent small bowel lipomatosis were seen. The affected ileal segment was resected, and the patient remained symptom-free after surgery. Abdominal lipomatosis is a rare condition which can be completely treated by resection of the affected gut segment but is often unsuspected and difficult to diagnose. In this report, we describe a case with the most extensive lipomatosis on record with more than 70 cm of gut with confluent lipomatosis. Magnetic resonance Enterography (MRE) is a useful non-invasive diagnostic modality, although laparoscopy/laparotomy may be necessary for assessment of the extent of disease. Symptomatic cases should be treated with segmental small bowel resection, which is curative.

Abstract Objective To evaluate the changes in magnetic resonance imaging-based body composition parameters during follow-ups in patients with Crohn's disease (CD). Methods Between November 1, 2017, and June 30, 2021, patients diagnosed with CD, who underwent two or more magnetic resonance enterography (MRE) scans at our institution were retrospectively reviewed. The baseline and one subsequent follow-up scan for each patient were paired to form longitudinal comparisons. Skeletal muscle, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) indexes were calculated from tissue areas measured at the third lumbar vertebra level per scan, standardized by dividing the height2 and lumbar height2 (heightL1–L5). We also assessed the correlation between changes in VAT to total adipose tissue ratio (VA/TA index) and CD activity scores (5-point MRE classification) using Spearman’s correlation analysis. A multivariate linear regression model was used to adjust for the follow-up duration and treatment type. Results Overall, 49 patients (with 49 paired scans) were enrolled. VA/TA index changes were negatively correlated with changes in skeletal muscle index (SMI; r = − 0.339, p 0.05). Changes in total MRE score were negatively correlated with SMI changes (r = − 0.408, p

Magnetic resonance enterography (MRE) is one of the most highly utilised tools in the assessment of patients with small bowel Crohn's disease (CD). As a non-invasive modality, it has both patient and procedure-related advantages over ileocolonoscopy which is the current gold standard for Crohn's disease activity assessment. MRE relies upon high-quality images to ensure accurate disease activity assessment; however, few studies have explored the impact of image quality on the accuracy of small bowel CD activity assessment. Bowel distension and motion artifacts are two key imaging parameters that impact the quality of images obtained through MRE. Multiple strategies have been employed to both minimise the effects of motion artifacts and improve bowel distension. This review discusses the definitions of bowel distension and motion artifacts within the literature with a particular focus on current strategies to improve bowel distension and limit motion artifacts in MRE. [ABSTRACT FROM AUTHOR]

Introduction: We hypothesized that, based on magnetic resonance enterography (MRE) and the apparent diffusion coefficient (ADC), measured in the affected parts of the intestine, it is possible to effectively differentiate active and chronic phases of Crohn's disease. Aim: To create a multidimensional diagnostic model for differentiating between the phases of Crohn's disease. Material and methods: This study included 125 patients - 55 women (aged 19 to 66 years) and 70 men (aged 12 to 67 years) - who underwent MRE and ADC measurement for the first time. Results: The group of potential explanatory variables comprised 11 variables, including the thickness and length of the occupied section, number of lymph nodes, layered bowel wall enhancement, total transitions on fat tissue, and features of restricted diffusion. The final discrimination model was based on 2 variables: ADC (A) and layered bowel wall enhancement (W). Active Crohn's disease was defined as -6.339 + 4.747 × W + 0.008 × A, while chronic Crohn's disease was defined as -11.365 + 2.812 × W + 0.012 × A. Definitive diagnosis was based on histological examination of material collected during ileocolonoscopy in 96 patients, surgery with subsequent histopathological examination in 17 patients, and capsule endoscopy in 12 patients. Conclusions: The predictive model described here could identify the active form of Crohn's disease with a probability of 93.06% and the chronic form with a probability of 75.57%. The use of classic MRE layered bowel wall enhancement and a DWIbased ADC metric eliminates the main shortcomings of both approaches. [ABSTRACT FROM AUTHOR]

Background and Aims The simplified magnetic resonance enterography [MRE] index of activity [sMARIA], London, and 'extended' London, scoring systems are widely used in Crohn's disease [CD] to assess disease activity, although validation studies have usually been single-centre, retrospective, and/or used few readers. Here, we evaluated these MRE indices within a prospective, multicentre, multireader, diagnostic accuracy trial. Methods A subset of participants [newly diagnosed or suspected of relapse] recruited to the METRIC trial with available terminal ileal [TI] biopsies was included. Using pre-specified thresholds, the sensitivity and specificity of sMARIA, London, and 'extended' London scores for active and severe [sMARIA] TI CD were calculated using different thresholds for the histological activity index [HAI]. Results We studied 111 patients [median age 29 years, interquartile range 21-41, 75 newly diagnosed, 36 suspected relapse] from seven centres, of whom 22 had no active TI CD [HAI = 0], 39 mild [HAI = 1], 13 moderate [HAI = 2], and 37 severe CD activity [HAI = 3]. In total, 26 radiologists prospectively scored MRE datasets as per their usual clinical practice. Sensitivity and specificity for active disease [HAI >0] were 83% [95% confidence interval 74% to 90%] and 41% [23% to 61%] for sMARIA, 76% [67% to 84%] and 64% [43% to 80%] for the London score, and 81% [72% to 88%] and 41% [23% to 61%] for the 'extended' London score, respectively. The sMARIA had 84% [69-92%] sensitivity and 53% [41-64%] specificity for severe CD. Conclusions When tested at their proposed cut-offs in a real-world setting, sMARIA, London, and 'extended' London indices achieve high sensitivity for active TI disease against a histological reference standard, but specificity is low. [ABSTRACT FROM AUTHOR]

Background: Magnetic resonance enterography (MRE) has emerged as a novel tool for the assessment of disease activity in Crohn's disease (CD). Real world data from Indian subcontinent on performance of MRE in terminal ileal CD are lacking. Methods: Retrospective analysis of patients with terminal ileal CD who underwent both ileo-colonoscopy and MRE was performed. Ileo-colonoscopy was considered the gold standard for assessment of disease activity. On ileo-colonoscopy, a simple endoscopic score for Crohn's disease (SES-CD) ≥2 was considered active disease; presence of ulcers indicated severe disease. MRE scoring of the disease activity was performed using magnetic resonance index of activity (MARIA) and simplified MARIA (MARIAs). The measure of agreement between ileo-colonoscopy and MRE and comparison of MARIA and MARIAs for assessment of disease activity and sensitivity of MRE to detect mucosal ulcerations were calculated. Results: Seventy patients with terminal ileal CD (mean age 40.74±15.56 years; 71.4% males [n=50]) were evaluated. The sensitivities of MARIA and MARIAs scores to detect active disease were 0.76 and 0.84, respectively. The area under the receiver operating characteristic curve (AUROC) for detecting severe disease was 0.836 (p<0.0001) for MARIA and 0.861 (p<0.0001) for MARIAs. For mild active disease, there was no agreement between SES-CD and MARIA or MARIAs; however, for severe disease, the agreement was fair and moderate for MARIA and MARIAs, respectively. MARIA and MARIAs were comparable for identification of active and severe disease (κ 0.759, p<0.0001 and κ 0.840, p<0.0001, respectively). MRE was 68.18% sensitive to detect mucosal ulcers. Conclusion: MRE is a reliable and sensitive tool for detection of endoscopically severe, but not mild, terminal ileal CD. [ABSTRACT FROM AUTHOR]

Diagnosis of intestinal vasculitis is often challenging due to the non-specific clinical and imaging findings. Vasculitides with gastrointestinal (GI) manifestations are rare, but their diagnosis holds immense significance as late or missed recognition can result in high mortality rates. Given the resemblance of radiologic findings with some other entities, GI vasculitis is often overlooked on small bowel studies done using computed tomography/magnetic resonance enterography (CTE/MRE). Hereon, we reviewed radiologic findings of vasculitis with gastrointestinal involvement on CTE and MRE. The variety of findings on MRE/CTE depend upon the size of the involved vessels. Signs of intestinal ischemia, e.g., mural thickening, submucosal edema, mural hyperenhancement, and restricted diffusion on diffusion-weighted imaging, are common in intestinal vasculitis. Involvement of the abdominal aorta and the major visceral arteries is presented as concentric mural thickening, transmural calcification, luminal stenosis, occlusion, aneurysmal changes, and collateral vessels. Such findings can be observed particularly in large- and medium-vessel vasculitis. The presence of extra-intestinal findings, including within the liver, kidneys, or spleen in the form of focal areas of infarction or heterogeneous enhancement due to microvascular involvement, can be another radiologic clue in diagnosis of vasculitis. The link between the clinical/laboratory findings and MRE/CTE abnormalities needs to be corresponded when it comes to the diagnosis of intestinal vasculitis. [ABSTRACT FROM AUTHOR]

(1) Background: Fecal calprotectin (FC) correlates well with colonic inflammatory activity of Crohn's disease (CD); data about relation of FC and small bowel (SB) lesions are still contradictory. The main aim was to analyze the relationship between FC levels and SB inflammatory activity in patients with established or suspected Crohn's disease, assessed by small bowel capsule endoscopy (SBCE) or magnetic resonance enterography (MRE). (2) Methods: Two cohorts of patients were included: 1. Prospective data were collected from patients with established or suspected CD who underwent SBCE and FC (Cohort A); 2. A retrospective cohort of patients who underwent MRE and FC determination (Cohort B). Different cutoffs for FC were tested in both cohorts. (3) Results: 83 patients were included and 66 were finally analyzed. A total of 69.6% had SB lesions seen by SBCE (n = 25) or MRE (n = 21). FC mean levels were 605.74 + 607.07 μg/g (IQ range: 99.00–878.75), being significantly higher in patients with SB lesions compared to patients without lesions (735.91 + 639.70 μg/g (IQ range: 107.75–1366.25) vs. 306.35 + 395.26 μg/g (IQ range: 78.25–411.0), p < 0.005). For cohort A, 25 out of 35 patients had SB lesions and a significant correlation between Lewis Score and FC levels was achieved (R2: 0.34; p = 0.04). FC sensitivity (S), specificity (E), positive predictive value (PPV), and negative predictive values (NPV) for predicting SB lesions were 80%, 50%, 80%, and 50%, respectively, for FC > 100 µg/g. For cohort B, inflammatory SB activity, measured by MaRIA score, was detected in 21 out of 31 patients (67.7%). Patients with positive findings in MRE had significantly higher values of FC than those with no lesions (944.9 + 672.1 µg/g vs. 221 + 212.2 µg/g, p < 0.05). S, E, PPV, and NPV of FC were 89%, 50%, 77.2%, and 71.4% for FC levels > 100 µg/g. The higher sensitivity and specificity of the FC levels for the detection of SB lesions with SBCE and MRE was obtained for an FC cutoff >265 μg/g and >430 μg/g, respectively. (4) Conclusions: FC has a good correlation with the presence of SB lesions, assessed by SBCE and MRE, in patients with established or suspected Crohn's disease. However, the ideal cutoff is here proven to be higher than previously reported. Multicenter and large prospective studies are needed in order to establish definitive FC cutoff levels. [ABSTRACT FROM AUTHOR]

Objectives: Patients with Crohn's disease (CD) usually undergo magnetic resonance enterography (MRE) for evaluating small bowel involvement. Musculoskeletal symptoms are the most frequent extraintestinal manifestation in inflammatory bowel diseases, especially in CD, with sacroiliitis at imaging occurring in about 6–46% of patients and possibly correlating with axial spondyloarthritis. The primary study aim was to assess the prevalence of sacroiliitis in adult and pediatric patients with CD performing an MRE. We also evaluated the inter-rater agreement for MRE sacroiliitis and the association between sacroiliitis and patients' clinical data. Method: We retrospectively identified 100 adult and 30 pediatric patients diagnosed with CD who performed an MRE between December 2012 and May 2020 in three inflammatory bowel disease centers. Two radiologists assessed the prevalence of sacroiliitis at MRE. We evaluated the inter-rater agreement for sacroiliitis with Cohen's kappa and intraclass correlation coefficient statistics and assessed the correlation between sacroiliitis and demographic, clinical, and endoscopic data (Chi-square and Fisher's tests). Results: The prevalence of sacroiliitis at MRE was 20% in adults and 6.7% in pediatric patients. The inter-rater agreement for sacroiliitis was substantial (k = 0.62, p < 0.001) in the adults and moderate (k = 0.46, p = 0.011) in the pediatric cohort. Age ≥ 50 years and the time between CD diagnosis and MRE (≥ 86.5 months) were significantly associated with sacroiliitis in adult patients (p = 0.049 and p = 0.038, respectively). Conclusions: Sacroiliitis is a frequent and reliable abnormality at MRE in adult patients with CD, associated with the age of the patients ≥ 50 years and CD duration. Key Points •Sacroiliitis incidentally detected at magnetic resonance enterography performed for Crohn's disease is a frequent and reliable finding in adult patients, rarer in the pediatric population. •Clinicians may rely on magnetic resonance enterography to properly evaluate and manage patients for sacroiliitis. [ABSTRACT FROM AUTHOR]

We aimed to evaluate and compare the diagnostic performances of ultrasonography (US) and magnetic resonance enterography (MRE) in assessing active bowel lesions in patients with Crohn's disease (CD). Materials and Methods: We searched PubMed and EMBASE for studies in which US and MRE were used to assess active bowel lesions in CD patients. Bivariate random effect meta-analytic methods were used to estimate pooled sensitivity, specificity, and hierarchical summary receiver operating characteristic (HSROC) curves. We performed a meta-regression analysis to explore the source of study heterogeneity. Results: Eleven studies involving 752 patients were included. US exhibited a pooled sensitivity of 86% (95% confidence interval (CI) 72–94), pooled specificity of 88% (95% CI 78–94), and HSROC of 0.93 in 10 studies. MRE exhibited a pooled sensitivity of 88% (95% CI 76–95), pooled specificity of 87% (95% CI 73–95), and an HSROC of 0.94 in eight studies. In seven studies comparing the diagnostic performances of US and MRE, the summary sensitivity of US and MRE were 86% (95% CI 65–96, I2 = 92.1) and 86% (95% CI 72–93, I2 = 88.1) (p = 0.841), respectively. The summary specificity of US and MRE were 87% (95% CI 78–93, I2 = 79.8%) and 84% (72–90, I2 = 72.5%) (p = 0.431), respectively, which showed no statistical differences. On meta-regression analysis, studies from Europe (p = 0.002), those that used linear US probes (p = 0.012), those on small bowel lesions (p = 0.01), and those with outcomes as combined features (active inflammation) reported higher US sensitivity than those from other regions, those that used both linear and convex US probes, those on small and large bowels, and those with outcome as one feature (bowel wall thickening or ulcer). Studies with pediatric patients (p = 0.001), those with reference standards including US (p = 0.001), and outcomes as combined features (p = 0.01) reported higher MRE specificity than those with adult populations, reference standards other than the US, and outcomes as one feature. Conclusions: In spite of considerable heterogeneity in the included studies, both US and MRE can diagnose active bowel lesions with comparable diagnostic accuracy in patients with CD. The study region, type of US probe, lesion location, investigated outcome for US sensitivity and study population, reference standards, and investigated outcomes for MRE specificity were potential sources of heterogeneity. [ABSTRACT FROM AUTHOR]