Magnetic Resonance Imaging Enterography Research Articles

Bright Luminal Sign on High b-Value Diffusion-Weighted Magnetic Resonance Enterography Imaging as a New Biomarker to Predict Fibrotic Strictures in Crohn's Disease Patients: A Retrospective Preliminary Study.

A retrospective analysis was conducted to investigate how a bright luminal sign on high b-value diffusion-weighted imaging (DWI) could be considered as a new biomarker for identifying fibrotic strictures in Crohn's disease (CD). Fibrotic strictures, due to excessive deposition of extracellular matrix following chronic inflammatory processes, can be difficult to distinguish from inflammatory strictures using endoscopy. This study was performed on 65 patients with CD who underwent MRE, and among them 32 patients showed the bright luminal sign on high b-value DWI. DWI findings were compared to pre- and post-contrast MRE data. Luminal bright sign performance results were calculated using a confusion matrix, the relationship between categorical variables was assessed by the χ2 test of independence, and the Kruskal-Wallis test (ANOVA) was used for the assessment of statistical significance of differences between groups. The results indicated a high sensitivity (90%) and specificity (85%) of the bright luminal sign for fibro-stenotic CD and a significant correlation between DWI luminal brightness and markers such as the homogeneous enhancement pattern (p < 0.001), increase in enhancement percentage from 70 s to 7 min after gadolinium injection (p < 0.001), and submucosal fat penetration (p = 0.05). These findings indicate that DWI hyperintensity can be considered as a good non-invasive indicator for the detection of severe intestinal fibrosis and may provide an efficient and accurate method for assessing fibrotic strictures. This new non-invasive biomarker could allow an early diagnosis of fibrotic stricture, delaying the onset of complications and subsequent surgery. Moreover, further evaluations through larger prospective trials with histopathological correlation are needed to confirm these results and completely determine the clinical benefits of DWI in treating CD.

Quantification of Visceral Fat at the L5 Vertebral Body Level in Patients with Crohn's Disease Using T2-Weighted MRI.

The umbilical or L3 vertebral body level is often used for body fat quantification using computed tomography. To explore the feasibility of using clinically acquired pelvic magnetic resonance imaging (MRI) for visceral fat measurement, we examined the correlation of visceral fat parameters at the umbilical and L5 vertebral body levels. We retrospectively analyzed T2-weighted half-Fourier acquisition single-shot turbo spin echo (HASTE) MR axial images from Crohn's disease patients who underwent MRI enterography of the abdomen and pelvis over a three-year period. We determined the area/volume of subcutaneous and visceral fat from the umbilical and L5 levels and calculated the visceral fat ratio (VFR = visceral fat/subcutaneous fat) and visceral fat index (VFI = visceral fat/total fat). Statistical analyses involved correlation analysis between both levels, inter-rater analysis between two investigators, and inter-platform analysis between two image-analysis platforms. Correlational analysis of 32 patients yielded significant associations for VFI (r = 0.85; p < 0.0001) and VFR (r = 0.74; p < 0.0001). Intraclass coefficients for VFI and VFR were 0.846 and 0.875 (good agreement) between investigators and 0.831 and 0.728 (good and moderate agreement) between platforms. Our study suggests that the L5 level on clinically acquired pelvic MRIs may serve as a reference point for visceral fat quantification.

P362 Mesenteric fat proliferation and fat edema in magnetic resonance enterography as predictor of long-term disease complications in Crohn’s disease

Abstract Background Fibrofatty proliferation of the mesenteric fat is a common finding in magnetic resonance enterography (MRE) in patients with Crohn’s disease (CD). Mesenteric fat is thought to play an active role in inflammation, fibrosis and stricture formation in CD. However, it is unclear whether these findings have a prognostic value in prediction of bowel damage and complications. We aimed to examine the association between mesenteric fat proliferation and inflammation on MRE and risk for hospital admissions and bowel surgery. Methods Patients with established CD diagnosis with at least 1 available MRE imaging data were followed for hospital admissions for CD exacerbation or abdominal surgery. MRE were reviewed by an expert radiologist for various characteristics (intestinal wall thickening and enhancement, stricture, or abscess formation, fibrofatty proliferation and fat edema reflecting fat inflammation). The association between mesenteric fat and outcomes was assessed using the Kaplan Meier method and log rank test. Crude and adjusted Hazard ratios (HR) with 95% confidence interval (CI) adjusting for baseline MRE characteristics (wall thickness and stricture and pre-stenotic dilatation) were estimated from the Cox proportional hazards regression model (R version 4.2.1). Results 159 CD patient charts and MRE imaging data were analyzed. Patients’ characteristics and medication exposure at described in table 1. On initial MRE the frequency of mesenteric fat proliferation was noted in 43 (27.0%) and fat edema in 79 (49.7%). Other MRE features noted were: mild, moderate and severe wall thickening in 72 (45.5%), 47 (29.9%) and 11 (7.0%) patients, respectively. Contrast intestinal wall enhancement was present in 122 (76.7%) patients. Intestinal stricture with pre-stenotic dilatation was noted in 17 (10.7%) patients and abscess and fistula formation was seen in 10 (6.3%) and 11 (6.9%) patients, respectively. During a mean (SD) follow up of 95.7 (39.5) months, 100 (62.9%) and 40 (25.2%) patients underwent hospitalization or surgery, respectively. On survival analysis, fat proliferation was associated with hospitalizations (Fig 1A, p=0.0005) and surgery (fig 1B, p&amp;lt;0.0001), while fat edema was associated with abdominal surgery (Fig 1D p=0.0003) but not with hospitalization (Fig 1C p=0.28). On multivariable analysis of the associations between fat proliferation and surgery and hospitalization remained highly significant (adjusted HR (95%CI) =3.15 (1.57-6.33) and adjusted HR (95%CI) =1.77 (1.06-2.97), respectively. Conclusion in this analysis of baseline MRE features, mesenteric fat proliferation was independently associated with increased risk for abdominal surgery and hospital admission for disease flares.

Magnetic Resonance Enterography Assessment of Transmural Healing with Vedolizumab in Moderate to Severe Crohn's Disease: Feasibility in the VERSIFY Phase 3 Clinical Trial.

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 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. 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%]). 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. ClinicalTrials.gov NCT02425111, April 23, 2015, http://www.clinicaltrials.gov NCT02425111; EU Clinical Trials Register EudraCT 2014-003509-13, https://www.clinicaltrialsregister.eu.

LAVA HyperSense and deep-learning reconstruction for near-isotropic (3D) enhanced magnetic resonance enterography in patients with Crohn's disease: utility in noise reduction and image quality improvement.

This study aimed to compare near-isotropic contrast-enhanced T1-weighted (CE-T1W) magnetic resonance enterography (MRE) images reconstructed with vendor-supplied deep-learning reconstruction (DLR) with those reconstructed conventionally in terms of image quality. A total of 35 patients who underwent MRE for Crohn's disease between August 2021 and February 2022 were included in this retrospective study. The enteric phase CE-T1W MRE images of each patient were reconstructed with conventional reconstruction and no image filter (original), with conventional reconstruction and image filter (filtered), and with a prototype version of AIRTM Recon DL 3D (DLR), which were then reformatted into the axial plane to generate six image sets per patient. Two radiologists independently assessed the images for overall image quality, contrast, sharpness, presence of motion artifacts, blurring, and synthetic appearance for qualitative analysis, and the signal-to-noise ratio (SNR) was measured for quantitative analysis. The mean scores of the DLR image set with respect to overall image quality, contrast, sharpness, motion artifacts, and blurring in the coronal and axial images were significantly superior to those of both the filtered and original images (P < 0.001). However, the DLR images showed a significantly more synthetic appearance than the other two images (P < 0.05). There was no statistically significant difference in all scores between the original and filtered images (P > 0.05). In the quantitative analysis, the SNR was significantly increased in the order of original, filtered, and DLR images (P < 0.001). Using DLR for near-isotropic CE-T1W MRE improved the image quality and increased the SNR.

P382 Serum Ustekinumab Concentrations are Associated with Improved Outcomes with the Magnetic Resonance Index of Activity for Crohn’s Disease

Abstract Background Controversy exists for ustekinumab concentrations needed in Crohn’s disease (CD). No data exist comparing ustekinumab concentrations and validated radiologic outcomes. We characterized these relationships and clarified concentrations needed. Methods CD patients on maintenance (&amp;gt; 16 weeks) ustekinumab with both ustekinumab concentrations and simplified magnetic resonance index of activity (sMaRIA) scoring were included. Ustekinumab concentrations were compared between those with and without (1) radiologic remission (sMaRIA &amp;lt; 2), (2) severe radiologic inflammation (sMaRIA &amp;lt; 3) and (3) fecal calprotectin (FCP) biomarker remission (FCP &amp;lt; 50μg/g). Area under the receiver-operating characteristic (AUROC) curve determined optimal ustekinumab concentrations. Outcomes were compared between patients above and below identified ustekinumab thresholds. Results Thirty-eight paired ustekinumab concentrations and magnetic resonance enterography imaging results were included. Ustekinumab concentrations were higher with radiologic remission (11.4μg/mL vs. 6.4μg/mL, P=.005) and had good diagnostic accuracy for radiologic remission (AUROC 0.76, 95% CI 0.60 – 0.91) and for absence of severe inflammation (AUROC 0.71, 95% CI 0.55 – 0.88, optimal concentration 8.4μg/mL). With ustekinumab ≥8.4μg/mL, higher proportions had radiologic remission (63.2% vs. 21.1%, P=.01) and absence of severe inflammation (78.9% vs. 36.8%, P=.01) compared to patients with lower concentrations. Ustekinumab concentrations had good diagnostic accuracy (AUROC 0.73, 95% CI 0.52 – 0.94) for FCP biomarker remission (optimal concentration: 6.1μg/mL). Patients with ustekinumab concentrations ≥6.1μg/mL had higher proportions with biomarker remission (72.2% vs. 12.5% P&amp;lt;.01) compared to those with lower concentrations. Conclusion Ustekinumab concentrations are associated with radiologic and biomarker outcomes in CD. These data validate the need for higher ustekinumab concentrations.

P248 The diagnostic accuracy of Intestinal ultrasound for assessing disease activity in the proximal ileum and jejunum in children with Crohn’s disease: Preliminary results of a prospective study

Abstract Background Crohn’s disease (CD) is an inflammatory bowel disease (IBD) involving mainly the small intestine and the colon. Current imaging modalities such as magnetic resonance enterography (MRE) to assess disease activity in the small bowel are expensive and are often poorly tolerated by children. Intestinal ultrasound (IUS) is a non-invasive and well tolerated monitoring tool for assessing disease activity in colon and terminal ileum. In children the diagnostic accuracy of IUS for proximal bowel has not been systematically studied. In this study we assess the diagnostic accuracy of IUS compared to MRE for the proximal ileum and jejunum in the paediatric population. Furthermore we aim to establish which IUS features are the best predictors for IBD activity in the proximal ileum and jejunum. Methods Paediatric CD patients were prospectively enrolled and underwent MRE and IUS within 7 days. MRE-images were scored using the segmental grading system by Tielbeek et al. The ultrasonographer was blinded for the MRE results and the paediatric radiologist who assessed the MRE images was blinded for IUS results. Results Forty-two paediatric CD patients underwent IUS paired with MRE until now. Eighty-four bowel segments were available for analyses. In total 24 bowel segments had mild (n=12) to moderate severe (n=12) disease activity based on MRE. The AUROC of BWT for moderate severe disease was 0.78 (95% CI 0.61-0.95). A cut-off value of BWT &amp;gt;2.5 mm showed had a specificity of 90%. A cut-off value of BWT &amp;lt;1.7 mm showed had a sensitivity of 91%. Of the affected segments 12 had increased Doppler signal and 13 showed mesenteric fat proliferation. No regression analysis was performed since the number of inflamed segments was too low. Conclusion IUS is an promising tool to non-invasively assess disease activity in the proximal ileum and jejunum. Our preliminary results suggest that a cut-off for BWT &amp;lt; 2,5mm IUS can be used to demonstrate disease activity. A lager sample size to perform regression analysis and to assess other IUS features for disease activity is currently being collected.

Presence of axial spondyloarthritis associated sacroiliitis and structural changes on MR enterography: A direct comparison with sacroiliac joint MRI

IntroductionTo investigate the acute inflammatory and structural changes of sacroiliitis as auxiliary findings on magnetic resonance enterography (MRE) and their presence on closely timed conventional magnetic resonance imaging of the sacroiliac joint (SI joint MRI). Materials and methodsWe screened axial spondyloarthritis patients for the simultaneous presence of MREs and SI joint MRIs. Two blinded radiologists evaluated SI joint MRIs and MREs on two separate occasions. We used the Assessment of SpondyloArthritis International Society (ASAS)/Outcome Measures in Rheumatology Network (OMERACT) definitions for SI joint MRI. We implemented previously published standard definitions for osteitis, erosion, sclerosis, and fatty infiltration of SI joint in MREs that contain T1w and T1w post-gadolinium sequences. ResultsSI joint MRI and MRE images were present in 43 patients. The median time between the two modalities was 14 (0–89) days. Twelve patients had ASAS-defined positive SI joint MRI. Radiologist-1 and radiologist-2 detected osteitis on MRE in nine and eight out of these 12 patients, respectively. The two radiologists detected ankylosis and fatty metaplasia with a complete agreement and sclerosis with an almost perfect agreement. Both radiologists agreed on erosions on SI joint MRI in the same 10 cases. Radiologists did not identify acute inflammatory or structural changes on MRE in patients with a negative SI joint MRI for these lesions. ConclusionAlong with intestinal findings, additional reporting of acute inflammatory and structural changes of the SI joint on a MRE is valuable and may alert physicians to the presence of previously not diagnosed axial spondyloarthritis.

Gastrointestinal Stromal Tumour in a Young Adult: A Case Report

Gastrointestinal Stromal Tumour (GIST) is the most common mesenchymal tumour. Peak ages are typically 60-65 years hence very few young adults present with GIST. Here, we present a case of a 26-year-old male with an acute chronic history of melena subsequently diagnose with GIST. No pathology was initially identified upon multiple gastroscopies and a colonoscopy. The patient then underwent Magnetic Resonance Imaging (MRI) Enterography which revealed a 5.6cm soft tissue mass in the right pelvis without any established evidence of bowel invasion. A Positron Emission Tomography (PET) scan did not reveal metastases. Laparoscopy was done and a small bowel resection was performed upon identifying the mass in the bowel. Histopathology analysis showed GIST with a TNM staging of IIIA. The patient was discharged 9 days later with Imatinib to be considered as adjuvant therapy. This case highlights the rarity of GIST seen in young adults presenting with undiagnosed abdominal symptoms as well as peri-operative investigations and surgical management.

Magnetic Resonance Enterography and Histology in Patients With Fibrostenotic Crohn's Disease: A Multicenter Study.

Magnetic resonance enterography (MRE) is useful for detecting bowel strictures, whereas a number of imaging biomarkers may reflect severity of fibrosis burden in Crohn's disease (CD). This study aimed to verify the association of MRE metrics with histologic fibrosis independent of inflammation. This prospective European multicenter study performed MRE imaging on 60 patients with CD with bowel strictures before surgical resection. Locations of 61 histological samples were annotated on MRE examinations, followed by central readings using the Chiorean score and measurement of delayed gain of enhancement (DGE), magnetization transfer ratio, T2-weighted MRI sequences (T2R), apparent diffusion coefficient (ADC), and the magnetic resonance index of activity (MaRIA). Correlations of histology and MRE metrics were assessed. Least Absolute Shrinkage and Selection Operator and receiver operator characteristic (ROC) curve analyses were used to select composite MRE scores predictive of histology and to estimate their predictive value. ADC and MaRIA correlated with fibrosis (R = -0.71, P < 0.0001, and 0.59, P < 0.001) and more moderately with inflammation (R = -0.35, P < 0.01, and R = 0.53, P < 0.001). Lower or no correlations of fibrosis or inflammation were found with DGE, magnetization transfer ratio, or T2R. Least Absolute Shrinkage and Selection Operator and ROC identified a composite score of MaRIA, ADC, and DGE as a very good predictor of histologic fibrosis (ROC area under the curve = 0.910). MaRIA alone was the best predictor of histologic inflammation with excellent performance in identifying active histologic inflammation (ROC area under the curve = 0.966). MRE-based scores for histologic fibrosis and inflammation may assist in the characterization of CD stenosis and enable development of fibrosis-targeted therapies and clinical treatment of stenotic patients.

The Role of Magnetic Resonance Enterography in Crohn's Disease: A Review of Recent Literature.

Inflammatory bowel disease (IBD) is the term used to identify a form of chronic inflammation of the gastrointestinal tract that primarily contemplates two major entities: ulcerative colitis (UC) and Crohn’s disease (CD). The classic signs are abdominal pain and diarrhoea that correlate with the localization of gastro-enteric disease, although in this pathology extraintestinal symptoms may coexist. The diagnosis of CD relies on a synergistic combination of clinical, laboratory (stool and biochemical), cross-sectional imaging evaluation, as well as endoscopic and histologic assessments. The purpose of this paper is to prove the role of imaging in the diagnosis and follow-up of patients with CD with particular focus on recent innovations of magnetic resonance enterography (MRE) as a pivotal diagnostic tool, analysing the MRE study protocol and imaging features during the various phases of disease activity and its complications.

Responsiveness of Magnetic Resonance Enterography Indices for Evaluation of Luminal Disease Activity in Crohn’s Disease

Magnetic resonance enterography (MRE) is having an increasing role in Crohn's disease; however, fully validated indices are needed. We evaluated the responsiveness of 4 MRE indices in luminal Crohn's disease. Paired MRE images (pretreatment and post-treatment at weeks 12 or 14) from 41 patients were scored by 3 blinded radiologists. Disease activity was scored for 4 MRE indices (magnetic resonance index of activity [MaRIA], simplified MaRIA, London index, and London extended index) and a 100-mm visual analog scale (VAS) of overall disease activity. The criterion for change was an improvement by at least one half of an SD in the VAS after treatment. Responsiveness was evaluated using the standardized effect size (SES). Longitudinal validity was evaluated using correlations between changes in MRE index scores and disease activity measures including endoscopy and the VAS. The SES was 1.17 (95% CI, 0.56-1.77) for the simplified MaRIA, 0.98 (95% CI, 0.42-1.55) for the MaRIA, 0.95 (95% CI, 0.38-1.51) for the London extended index, and 0.85 (95% CI, 0.31-1.39) for the London index. The simplified MaRIA was significantly more responsive than the London index (ΔSES, 0.32; 95% CI, 0.05-0.58) but not the MaRIA (ΔSES, 0.18; 95% CI, -0.01 to 0.38) or the London extended index (ΔSES, 0.22; 95% CI, -0.05 to 0.50). Correlations with endoscopy (simplified MaRIA: r= 0.72) were not different from correlations with the VAS (London extended index: r= 0.70). Evaluated MRE indices showed moderate-to-large responsiveness and are suitable for use in clinical trials. The simplified MaRIA may be preferred because of its responsiveness and nonreliance on gadolinium administration.

Sensitivity of pre-operative imaging and radiologist inter-rater reliability in detecting lesions in Crohn's disease.

Computed tomography (CT), computed tomography enterography (CTE) and magnetic resonance enterography (MRE) are commonly used pre-operatively in surgical planning in Crohn's Disease (CD). The findings on CT, CTE and MRE may not, however, correlate with operative findings. This study aims to establish the sensitivity of these imaging modalities and analyse radiologist inter-rater reliability by comparing imaging findings of strictures, fistulas and abscesses with intra-operative findings. A retrospective review of CD patients who had either CT, CTE and/or MRE imaging and CD related surgical intervention at a public health service from 2010 to 2019 inclusive. The number and locations of strictures, fistulas and abscesses on pre-operative original radiology reports (OR) were recorded. Subsequently, all scans were re-read by two specialist abdominal radiologists and consensus recorded (SR). Lesions recorded from both OR and SR were compared to those found intra-operatively. Eighty-three patients were included. For strictures, sensitivity was 67%, 74% and 79% for OR and 88%, 71% and 87% for SR for CT, CTE and MRE respectively. The frequency of fistulas and abscesses were small hence a conclusion could not be drawn. The level of agreement between radiologists ranged from 44% to 82% for strictures and 64 to 100% for fistulas and abscesses across all three imaging modalities. CT and MRE have similarly high sensitivities for the identification of strictures pre-operatively when read by specialist radiologists. Inter-rater reliability calculations found similar agreement levels between specialist radiologists and between OR and SR for strictures, fistulas and abscesses across CT, CTE and MRE.

Predicting Risk of Surgery in Patients With Small Bowel Crohn's Disease Strictures Using Computed Tomography and Magnetic Resonance Enterography.

We aimed to determine if patient symptoms and computed tomography enterography (CTE) and magnetic resonance enterography (MRE) imaging findings can be used to predict near-term risk of surgery in patients with small bowel Crohn's disease (CD). CD patients with small bowel strictures undergoing serial CTE or MRE were retrospectively identified. Strictures were defined by luminal narrowing, bowel wall thickening, and unequivocal proximal small bowel dilation. Harvey-Bradshaw index (HBI) was recorded. Stricture observations and measurements were performed on baseline CTE or MRE and compared to with prior and subsequent scans. Patients were divided into those who underwent surgery within 2 years and those who did not. LASSO (least absolute shrinkage and selection operator) regression models were trained and validated using 5-fold cross-validation. Eighty-five patients (43.7±15.3 years of age at baseline scan, majority male [57.6%]) had 137 small bowel strictures. Surgery was performed in 26 patients within 2 years from baseline CTE or MRE. In univariate analysis of patients with prior exams, development of stricture on the baseline exam was associated with near-term surgery (P = .006). A mathematical model using baseline features predicting surgery within 2 years included an HBI of 5 to 7 (odds ratio [OR], 1.7×105; P = .057), an HBI of 8 to 16 (OR, 3.1×105; P = .054), anastomotic stricture (OR, 0.002; P = .091), bowel wall thickness (OR, 4.7; P = .064), penetrating behavior (OR, 3.1×103; P = .096), and newly developed stricture (OR: 7.2×107; P = .062). This model demonstrated sensitivity of 67% and specificity of 73% (area under the curve, 0.62). CTE or MRE imaging findings in combination with HBI can potentially predict which patients will require surgery within 2 years.

Diagnostic significance of mesenteric lymph node involvement in proximal small bowel Crohn's disease.

Background:The diagnosis of proximal small bowel involvement in Crohn’s disease (CD) can be challenging at magnetic resonance enterography (MRE). The inflammatory process in CD can be associated with peri-intestinal inflammatory reactions, including the presence of inflamed mesenteric lymph nodes.Objectives:To evaluate the significance of inflamed mesenteric lymph nodes adjacent to the jejunum at MRE in CD and the association with proximal bowel disease as detected by video capsule endoscopy (VCE).Design:This retrospective study was performed in two tertiary medical centres, and included 64 patients with CD who underwent MRE as well as VCE within 1 year.Methods:Data were collected for examinations performed between August 2013 and February 2021. MRE images were independently reviewed by radiologists who were blinded to the clinical data. Association between the presence of mesenteric lymph nodes adjacent to jejunum at MRE and disease activity according to VCE Lewis scores of proximal small bowel was examined.Results:VCE detected proximal disease in 24/64 patients (37.5%). Presence of regional lymph nodes in the jejunal mesentery was significantly associated with jejunal disease as seen on VCE (p < 0.001). Of the 20 patients who had proximal mesenteric lymph nodes at MRE, 15 (75%) had jejunal disease at VCE (sensitivity, 62.5%; specificity, 87.5%; and negative and positive predictive values, 79.5 and 75%, respectively). The number of regional lymph nodes was positively correlated with jejunal disease (mean: 2.63 ± 2.90 versus 0.78 ± 2.60, p = 0.01). Other MRE features of lymph nodes were not significantly predictive of jejunal CD.Conclusion:In patients with CD, inflamed regional lymph nodes in the jejunal mesentery at MRE can be valuable to suggest proximal small bowel disease, even when bowel wall features at imaging do not suggest disease involvement.Plain language summaryThe diagnosis of proximal small bowel involvement in Crohn’s disease (CD) can be challenging at magnetic resonance enterography (MRE). We analysed MRE examinations in patients with CD for the presence of lymph nodes adjacent to the proximal small bowel. We included 64 patients with CD who had MRE examinations and video capsule endoscopy (VCE) examinations within 1 year. Of 64 patients, 24 had proximal small bowel disease according to VCE. We found that of 20 patients who had regional mesenteric lymph nodes in the jejunal mesentery at MRE, 15 had proximal bowel disease involvement. We also found that patients with jejunal disease had a larger number of regional lymph nodes compared to patients without jejunal disease. All but one patient had normal appearing bowel at MRE. But, using regional mesenteric lymphadenopathy at MRE as an indicator for disease, 15/24 (62.5%) patients with proximal small bowel disease were detected. We therefore conclude that regional mesenteric lymph nodes assessment at MRE can aid diagnose proximal bowel disease, even when the proximal bowel looks normal at imaging. Presence of proximal mesenteric lymph nodes at MRE in patients with CD possibly warrant further investigation of the proximal small bowel by endoscopic measures.

The Role of MR Enterography in Crohn’s Disease

Aim: The aim of this study was to investigate the efficacy of magnetic resonance enterography (MRE) in the diagnosis and follow-up of Crohn’s Disease. Material and Methot: Between November 2013 and April 2014, patients who were MRE examinations for a preliminary or definitive diagnosis of Crohn’s Disease were reviewed retrospectively. MRE imaging of the patients was performed on an 8-channel 1.5 Tesla MRI device. Primary and secondary MRE results and contrast enhancement patterns of active and chronic inflammation of Crohn’s disease in jejunum, ileum, terminal ileum, and colon segments were evaluated by two radiologists. Results: The results consistent with Crohn’s Disease were detected in 19 (10 male, 9 female) of 42 patients (24 male, 18 female, mean age was 40.64 years, min-max: 20-69, SD±14.27). Signs of active inflammation which were intestinal wall thickening, T2 signal reduction, and pathological mucosal contrast enhancement were observed in 19 patients (26 intestinal segments). Active inflammation findings were most common in the terminal ileum, with 16 (61.5%), followed by 5 (19.2%) in the ascending colon, 2 (7.6%) in the jejunum, 2 (7.6%) in the nonterminal ileum, and 1 (3.8%) in the sigmoid colon. Chronic inflammation findings such as intestinal stenosis (18 intestinal segments), submucosal fat deposition (16 intestinal segments), and prestenotic dilatation (13 intestinal segments) were observed in 13 patients. There was an ileosigmoid fistula in 1 patient, enterovesical fistula in 1 patient, and enterocutaneous fistula in 1 patient. Conclusion: MRE is an appropriate diagnostic method without ionizing radiation, which can be used to detect the stage of inflammation (active or chronic) in the diseased intestinal segments in the diagnosis and follow-up of Crohn’s disease.

Specific Plasma MicroRNA Signatures in Predicting and Confirming Crohn's Disease Recurrence: Role and Pathogenic Implications.

INTRODUCTION:MicroRNAs (miRNAs) are important epigenetic regulators in Crohn's disease (CD); however, their contribution to postoperative recurrence (POR) is still unknown. We aimed to characterize the potential role of miRNAs in predicting POR in patients with CD and to identify their pathogenic implications.METHODS:Of 67 consecutively operated patients with CD, we included 44 with pure ileal CD. Peripheral blood samples were taken before surgery and during follow-up. The patients were classified according to the presence or absence of POR assessed by ileocolonoscopy or magnetic resonance imaging enterography. The miRNAs were profiled by reverse transcription polymerase chain reaction before surgery and during morphological POR or, for those who remained in remission, 1 year after surgery. R software and mirWalk were used.RESULTS:Five human miRNAs (miR-191-5p, miR-15b-5p, miR-106b-5p, miR-451a, and miR-93-5p) were selected for discriminating between the 2 patient groups at presurgery (PS), with an area under the curve of 0.88 (95% confidence interval [0.79, 0.98]). Another 5 (miR-15b-5p, miR-451a, miR-93-5p, miR-423-5p, and miR-125b-5p) were selected for 1 year, with an area under the curve of 0.96 (95% confidence interval [0.91, 1.0]). We also created nomograms for POR risk estimation. CCND2 and BCL9L genes were related to PS miRNA profiles; SENP5 and AKT3 genes were related to PS and 1 year; and SUV39H1 and MAPK3K10 were related to 1 year.DISCUSSION:Different plasma miRNA signatures identify patients at high POR risk, which could help optimize patient outcomes. We developed nomograms to facilitate the clinical use of these results. The identified miRNAs participate in apoptosis, autophagy, proinflammatory immunological T-cell clusters, and reactive oxygen species metabolism.

Assessment of Imaging Features of Crohn's Disease with MR Enterography.

To evaluate the frequency of pathological findings determined on magnetic resonance (MR) enterography (MRE) in patients with Crohn's Disease. A retrospective analysis of the MRE images was made in 34 female and 41 male patients (mean age 41 years) with Crohn's disease. The prevalence of bowel wall (mural thickening, mural edema, mural fat deposits, mucosal enhancement, ulceration, cobblestone appearance, pseudopolyps) and mesenteric fatty tissue alterations (fatty tissue proliferation, mesenteric hypervascularity, enlarged lymph nodes, peri-enteric inflammation, reactive fluid), complications due to penetrating (fistula, sinus tract, abscess) and stenosing processes (fibrotic and inflammatory stenosis, obstruction, dilatation), and involvement of the colon were determined. The most frequently observed changes in the bowel wall and mesenteric fatty tissue were mural thickening (98.7%) and enlargement of mesenteric lymph nodes (76%), respectively. Stenosis was the most common complication (76%). The most frequently seen pathology of the colon was ileocecal valve thickening and enhancement (74.7%). MR enterography is a useful imaging modality for the evaluation of changes in both the mesenteric fatty tissue and the bowel wall. As there is no use of ionizing radiation, MR enterography should be the preferred imaging modality during follow-up of patients with Crohn's disease.

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

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. 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. 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. 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. 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.

The magnetic resonance enterography imaging features of symptomatic Meckel's diverticulum in pediatric patients: a retrospective observational study of 31 cases.

BackgroundThe aim of this study was to explore the magnetic resonance enterography (MRE) imaging manifestations of a symptomatic Meckel’s diverticulum (MD) in pediatric patients in order to provide a reference for the diagnosis of the condition.MethodsThe medical records of 31 pediatric patients with MD from May 2014 to October 2020 were retrospectively analyzed. The inclusion criteria were patients with MD accompanied by unexplained gastrointestinal bleeding, anemia (except hematological diseases), chronic persistent abdominal pain, repeated intussusception, or intussusception in older pediatric patients during surgery. The clinical variables (age, sex, and hemoglobin) and imaging, surgical, and pathological findings were recorded.ResultsMD was definitively identified in 28 patients, with the following characteristics: a blind-ending fluid-filled and/or gas-filled structure (n=23), an elongated shape (n=1), a dumbbell shape (n=1), and a solid mass (n=3). The diverticula were located in the right lower quadrant (n=16), the right abdomen at the level of the umbilicus (n=3), the right upper quadrant (n=2), the left upper quadrant (n=2), and the midline lower abdomen (n=5). Supply arteries were visualized in nine cases. In all cases, mural enhancement was comparable to that of the adjacent small-bowel (SB). Extravasation of the intravascular contrast medium was seen in two cases. Peripheral structural abnormalities included mesenteric fat stranding (n=7), hemorrhage in the adjacent lumen (n=3), free intraperitoneal gas (n=1), abnormal fluid retention (n=2), intestinal obstruction (n=1), and lymph node enlargement (n=7). A normal appendix was identified in 18 cases.ConclusionsMRE is an appropriate method of diagnosing symptomatic MD in pediatric patients and is particularly useful in the assessment of complications.