The aim of this study is to determine the interrater agreement in a clinical practice environment for the most commonly used magnetic resonance enterography (MRE) features of Crohn's disease (CD).

CD patients with MRE's before and after treatment were retrospectively identified using search queries over a 7-year period (May 2017-September 2017). MRE features of CD comprising components of multiple CD scoring indices were scored by radiologists in the same segment of bowel. Agreement for nominal categorical and continuous variables was assessed using a κ and interclass correlation coefficients, respectively.

80 scans comprised the study population. Moderate interrater agreement was seen in both the pre- and post-treatment MRE's for presence of diffusion restriction (к = 0.43, 0.48; pre- and post-treatment), stricturing disease (к = 0.51, 0.52), overall degree of severity (к = 0.49, 0.59). Substantial agreement was seen in pre- and post-treatment scans for length of involvement (interclass correlation coefficient = 0.67, 0.61). The presence of mucosal ulceration had no agreement (к = -0.07, -0.042).

Many MRE features of active CD comprising the major CD scoring indices are reproducible when interpreted by non-CD focused abdominal radiologists. However, the presence of mucosal ulcerations had no agreement and may need more investigation before including this feature as a driver in therapeutic decision making.

Demonstrates the unreliability of mucosal ulceration by non-CD focused abdominal radiologists, targeting a potential area for future education. Key Points The majority of MRE findings incorporated in to many CD scoring indices have fair to moderate inter-rater agreement even when read by non-MRE expert radiologists. Substantial agreement was seen in the length of involved bowel, but this feature is only incorporated in to one of the CD scoring indices. Presence of mucosal ulcerations had no interrater agreement in our study-a feature which is heavily weighted by several CD scoring indices. Research should be focused bridging those features which have poor interrater agreement.

To investigate the subjective and quantitative image quality and radiation exposure of CT enterography (CTE) examination performed at low tube voltage and low concentration of contrast agent with adaptive statistical iterative reconstruction (ASIR) algorithm, compared with conventional CTE.One hundred thirty-seven patients with suspected or proved gastrointestinal diseases underwent contrast enhanced CTE in a multidetector computed tomography (MDCT) scanner. All cases were assigned to 2 groups. Group A (n = 79) underwent CT with low tube voltage based on patient body mass index (BMI) (BMI < 23 kg/m, 80 kVp; BMI ≥ 23 kg/m, 100 kVp) and low concentration of contrast agent (270 mg I/mL), the images were reconstructed with standard filtered back projection (FBP) algorithm and 50% ASIR algorithm. Group B (n = 58) underwent conventional CTE with 120 kVp and 350 mg I/mL contrast agent, the images were reconstructed with FBP algorithm. The computed tomography dose index volume (CTDIvol), dose length product (DLP), effective dose (ED), and total iodine dosage were calculated and compared. The CT values, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) of the normal bowel wall, gastrointestinal lesions, and mesenteric vessels were assessed and compared. The subjective image quality was assessed independently and blindly by 2 radiologists using a 5-point Likert scale.The differences of values for CTDIvol (8.64 ± 2.72 vs 11.55 ± 3.95, P < .001), ED (6.34 ± 2.24 vs 8.52 ± 3.02, P < .001), and DLP (422.6 ± 149.40 vs 568.30 ± 213.90, P < .001) were significant between group A and group B, with a reduction of 25.2%, 25.7%, and 25.7% in group A, respectively. The total iodine dosage in group A was reduced by 26.1%. The subjective image quality did not differ between the 2 groups (P > .05) and all image quality scores were greater than or equal to 3 (moderate). Fifty percent ASIR-A group images provided lower image noise, but similar or higher quantitative image quality in comparison with FBP-B group images.Compared with the conventional protocol, CTE performed at low tube voltage, low concentration of contrast agent with 50% ASIR algorithm produce a diagnostically acceptable image quality with a mean ED of 6.34 mSv and a total iodine dose reduction of 26.1%.

Purpose e Cross-sectional imaging methods are important for objective evaluationof small intestinal inflammationinCrohn'sdisease(CD).The primary aim was to compare relative parameters of intestinal perfusion between contrast-enhanced ultrasonography (CEUS) and dynamic contrast-enhanced magnetic resonance enterography (DCE-MRE) in CD. Furthermore, we aimed at testing the repeatability of regions of interest (ROIs) for CEUS. Methods This prospective study included 25 patients: 12 females (age: 37, range: 19-66) with moderate to severe CD and a bowel wall thickness>3mm evaluated with DCE-MRE and CEUS. CEUS bolus injection was performed twice for repeatability and analyzed in VueBox®. Correlations between modalities were described with Spearman's rho, limits of agreement(LoA) and intraclass correlation coefficient(ICC). ROIrepeatability for CEUS was assessed. Results s The correlation between modalities was good and very good for bowel wall thickness (ICC=0.71, P<0.001) and length of the inflamed segment (ICC=0.89, P<0.001). Moderate-weak correlations were found for the time-intensity curve parameters: peak intensity (r=0.59, P=0.006), maximum wash-in-rate (r=0.62, P=0.004), and wash-in perfusion index (r=0.47, P=0.036). Best CEUS repeatability for peak enhancement was a mean difference of 0.73 dB (95% CI: 0.17 to 1.28, P=0.01) and 95% LoA from -3.8 to 5.3 dB. Good quality of curve fit improved LoA to -2.3 to 2.8 dB. Conclusion The relative perfusion of small intestinal CD assessed with DCE-MRE and CEUS shows only a moderate correlation. Applying strict criteria for ROIs is important and allows for good CEUS repeatability.

The purpose of this article was to assess the feasibility of golden-angle radial acquisition with compress sensing reconstruction (Golden-angle RAdial Sparse Parallel [GRASP]) for acquiring high temporal resolution data for pharmacokinetic modeling while maintaining high image quality in patients with Crohn disease terminal ileitis.

Fourteen patients with biopsy-proven Crohn terminal ileitis were scanned using both contrast-enhanced GRASP and Cartesian breath-hold (volume-interpolated breath-hold examination [VIBE]) acquisitions. GRASP data were reconstructed with 2.4-second temporal resolution and fitted to the generalized kinetic model using an individualized arterial input function to derive the volume transfer coefficient (K(trans)) and interstitial volume (v(e)). Reconstructions, including data from the entire GRASP acquisition and Cartesian VIBE acquisitions, were rated for image quality, artifact, and detection of typical Crohn ileitis features.

Inflamed loops of ileum had significantly higher K(trans) (3.36 ± 2.49 vs 0.86 ± 0.49 min(-1), p < 0.005) and v(e) (0.53 ± 0.15 vs 0.20 ± 0.11, p < 0.005) compared with normal bowel loops. There were no significant differences between GRASP and Cartesian VIBE for overall image quality (p = 0.180) or detection of Crohn ileitis features, although streak artifact was worse with the GRASP acquisition (p = 0.001).

High temporal resolution data for pharmacokinetic modeling and high spatial resolution data for morphologic image analysis can be achieved in the same acquisition using GRASP.

The use of imaging in the management of inflammatory bowel disease (IBD) has grown exponentially in the last few years. This has raised concerns about the risk of high cumulative level of radiation exposure from medical imaging in IBD patients during their lifetime, especially when the disease begins in pediatric age. Physicians caring for IBD children should be aware of the malignant potential of ionizing radiation and of the availability of alternative radiation-free techniques such as magnetic resonance imaging (MRI) and ultrasonography (US), in order to use them whenever possible. This review will focus on the value of US and MRI in pediatric IBD.

To compare prospectively the diagnostic accuracy of magnetic resonance imaging (MRI) without use of contrast medium orally or intravenously (plain MRI) with magnetic resonance follow-through (MRFT) in patients with inflammatory bowel disease (IBD).

Plain MRI was carried out in addition to MRFT, to which the patients were referred. All patients underwent both examinations on the same day. For the evaluation, the bowel was divided into nine segments. Two radiologists, blinded to clinical findings, evaluated bowel wall thickness, diffusion weighted imaging (DWI), and other inflammatory changes in each bowel segments. Further, hyperenhancement of the bowel was also evaluated in MRFT.

A total of 100 patients (40 males and 60 females; median age: 38.5; range: 19-90) were enrolled; 44 with Crohn's disease (CD), 25 with ulcerative colitis (UC), 24 with IBD unclassified (IBD-U), and 7 had other diagnosis. Sensitivity, specificity, and accuracy in CD ranged 50-86%, 93-94%, and 91-92% for wall thickening and 49-82%, 85-93%, and 84-89% for DWI, respectively. Sensitivity, specificity, and accuracy in UC range 0-40%, 87-100%, and 80-100% for wall thickening and 0-52%, 83-94% and 76-92% for DWI, respectively. The κ values for bowel wall thickening, DWI, and mural hyperenhancement were detected with fair agreement (κ = 0.26-0.39) at both MRI examinations, whereas only bowel wall thickening in MRFT were detected with moderate agreement (κ = 0.47) Conclusion. Plain MRI cannot currently replace MRFT in the workup of patients with IBD. Further research on plain MRI is needed to improve the protocol.

Endoscopy is currently the primary diagnostic technique for inflammatory bowel disease (IBD) in children.

To assess the accuracy of US and dynamic contrast-enhanced MRI for diagnosing inflammatory bowel disease and for distinguishing Crohn disease and ulcerative colitis in comparison to a reference standard.

Consecutive children with suspected IBD underwent diagnostic workup including ileocolonoscopy and upper gastrointestinal endoscopy as the reference standard, abdominal US, and MR enterography and colonography at 3 T. The protocol included a dynamic contrast-enhanced 3-D sequence. Sensitivity, specificity and kappa values were calculated for one ultrasonographer and two MRI observers.

We included 28 children (15 boys) with mean age 14 years (range 10-17 years). The diagnosis was IBD in 23 children (72%), including 12 with Crohn disease, 10 with ulcerative colitis and 1 with indeterminate colitis. For the diagnosis of inflammatory bowel disease the sensitivity was 55% for US and 57% (both observers) for MR entero- and colonography, and the specificity was 100% for US and 100% (observer 1) and 75% (observer 2) for MR entero- and colonography. Combined MRI and US had sensitivity and specificity of 70% and 100% (observer 1) and 74% and 80% (observer 2), respectively. With the addition of a dynamic contrast-enhanced MR sequence, the sensitivity increased to 83% and 87%. US and MRI could only distinguish between Crohn disease and ulcerative colitis when terminal ileum lesions were present.

US and MR entero- and colonography have a high accuracy for diagnosing inflammatory bowel disease in children but cannot be used to distinguish Crohn disease and ulcerative colitis.

Magnetic resonance enterography (MRE) is a relatively new imaging modality that has shown promise for diagnosing, staging, and monitoring Crohn's disease (CD) and its complications while avoiding exposure to ionizing radiation. In addition to clinical implications, MRE has the potential to be used as an objective measure of disease activity for clinical trials. We provide the rationale for MRE, indications for its use, and an overview of the typical procedure and common findings for institutions who want to begin or refine the use of MRE for CD.

The purpose of this article is to assess the interobserver variability for scoring MRI features of Crohn disease activity and to correlate two MRI scoring systems to the Crohn disease endoscopic index of severity (CDEIS).

Thirty-three consecutive patients with Crohn disease undergoing 3-T MRI examinations (T1-weighted with IV contrast medium administration and T2-weighted sequences) and ileocolonoscopy within 1 month were independently evaluated by four readers. Seventeen MRI features were recorded in 143 bowel segments and were used to calculate the MR index of activity and the Crohn disease MRI index (CDMI) score. Multirater analysis was performed for all features and scoring systems using intraclass correlation coefficient (icc) and kappa statistic. Scoring systems were compared with ileocolonoscopy with CDEIS using Spearman rank correlation.

Thirty patients (median age, 32 years; 21 women and nine men) were included. MRI features showed fair-to-good interobserver variability (intraclass correlation coefficient or kappa varied from 0.30 to 0.69). Wall thickness in millimeters, presence of edema, enhancement pattern, and length of the disease in each segment showed a good interobserver variability between all readers (icc = 0.69, κ = 0.66, κ = 0.62, and κ = 0.62, respectively). The MR index of activity and CDMI scores showed good reproducibility (icc = 0.74 and icc = 0.78, respectively) and moderate CDEIS correlation (r = 0.51 and r = 0.59, respectively).

The reproducibility of individual MRI features overall is fair to good, with good reproducibility for the most commonly used features. When combined into the MR index of activity and CDMI score, overall reproducibility is good. Both scores show moderate agreement with CDEIS.

To prospectively compare conventional MRI sequences, dynamic contrast enhanced (DCE) MRI and diffusion weighted imaging (DWI) with histopathology of surgical specimens in Crohn's disease.

3-T MR enterography was performed in consecutive Crohn's disease patients scheduled for surgery within 4 weeks. One to four sections of interest per patient were chosen for analysis. Evaluated parameters included mural thickness, T1 ratio, T2 ratio; on DCE-MRI maximum enhancement (ME), initial slope of increase (ISI), time-to-peak (TTP); and on DWI apparent diffusion coefficient (ADC). These were compared with location-matched histopathological grading of inflammation (AIS) and fibrosis (FS) using Spearman correlation, Kruskal-Wallis and Chi-squared tests.

Twenty patients (mean age 38 years, 12 female) were included and 50 sections (35 terminal ileum, 11 ascending colon, 2 transverse colon, 2 descending colon) were matched to AIS and FS. Mural thickness, T1 ratio, T2 ratio, ME and ISI correlated significantly with AIS, with moderate correlation (r = 0.634, 0.392, 0.485, 0.509, 0.525, respectively; all P < 0.05). Mural thickness, T1 ratio, T2 ratio, ME, ISI and ADC correlated significantly with FS (all P < 0.05).

Quantitative parameters from conventional, DCE-MRI and DWI sequences correlate with histopathological scores of surgical specimens. DCE-MRI and DWI parameters provide additional information.

• Conventional MR enterography can be used to assess Crohn's disease activity. • Several MRI parameters correlate with inflammation and fibrosis scores from histopathology. • Dynamic contrast enhanced imaging and diffusion weighted imaging give additional information. • Quantitative MRI parameters can be used as biomarkers to evaluate Crohn's disease activity.

MRI is increasingly advocated as a robust method for quantifying disease activity in Crohn's disease. In particular, T1-weighted gadolinium-enhanced imaging shows considerable promise as a marker of inflammatory activity. However, interpretation of the literature must be made with an understanding of (i) the technical limitations of T1-weighted acquisition protocols and enhancement measurements; (ii) differences in standards of reference for disease activity employed between published studies; and (iii) important underlying macro and micro vascular changes in Crohn's disease. This review will focus specifically on the value of T1-weighted gadolinium-enhanced imaging in the assessment of wall inflammation and fibrosis.

Magnetic resonance imaging is increasingly used for abdominal evaluation and is more and more considered as the optimal imaging technique for detection of mural inflammation in patients with Crohn's disease. Grading the disease activity is important in daily clinical practice to monitor the medical treatment and is assessed by evaluating different magnetic resonance imaging features. Unfortunately, only moderate interobserver agreement is reported for most of the subjective features and should be improved. A computer-assisted model for automatic detection of abnormalities, ability to grade disease severity, and thereby influence clinical disease management based on magnetic resonance imaging is missing. Recent techniques have focused on semi-automated methods for classification and segmentation of the bowel and also on objective measurement of bowel wall enhancement using absolute T1-values or dynamic contrast-enhanced imaging. This article reviews the available computerized techniques, as well as preferred developments.

Magnetic resonance imaging (MRI) has evolved as a powerful tool for the assessment of the small bowel. Strengths of MRI include the superb soft-tissue contrast, lack of radiation exposure, and the implementation of fast scanning techniques. Clinically relevant findings such as inflammation and tumor disease can be well-depicted. We describe in this article current techniques of small bowel MRI including its implementation and clinical outcome in comparison to other radiological and endoscopic procedures.

Small-bowel radiology has undergone dramatic changes in the past 2 decades. Despite important recent advances in small-bowel endoscopy, radiologic imaging remains important for patients suspected of having or with established small-bowel disease. Cross-sectional imaging techniques (computed tomography and magnetic resonance [MR] imaging), used to investigate both extraluminal abnormalities and intraluminal changes, have gradually replaced barium contrast examinations, which are, however, still used to examine early mucosal disease. MR imaging techniques clearly highlight endoluminal, mural and extramural enteric details and provide vascular and functional information, thereby enhancing the diagnostic value of these techniques in small-bowel diseases. Two MR imaging based techniques are currently utilized: MR enteroclysis and MR enterography. In enteroclysis, enteric contrast material is administered through a nasoenteric tube, whereas in enterography, large volumes of enteric contrast material are administered orally. MR enteroclysis ensures consistently better luminal distention than does MR enterography in both the jejunum and the ileum and more accurately depicts endoluminal abnormalities and early disease, particularly at the level of the jejunal loops. Moreover, MR enteroclysis provides a high level of accuracy in the diagnosis and exclusion of small-bowel inflammatory and neoplastic diseases and can be used for the first radiologic evaluation, while MR enterography may effectively be used to follow up both Crohn disease patients without jejunal disease and in pediatric patients where nasogastric intubation might be a problem. MR enteroclysis may also reveal subtle transition points or an obstruction in the lower small bowel, which may escape detection when more routine methods, including enterography, are used. MR imaging offers detailed morphologic information and functional data of small-bowel diseases and provides reliable evidence of normalcy, thereby allowing the diagnosis of early or subtle structural abnormalities and guiding treatment and decisions in patient care.

Investigation of the small bowel has been traditionally a challenge for pediatric gastroenterologists due to its location, anatomical tortuosity, and invasiveness of the available techniques. Recently, there has been a remarkable improvement in imaging and endoscopic tools aimed at exploring successfully the small intestine in inflammatory bowel disease. The former are represented by ultrasonography (either alone or with administration of oral contrast agents) and by magnetic resonance: both have provided accurate methods to detect structural bowel changes, diminishing patient discomfort and precluding radiation hazard. The use of traditional radiologic techniques such as fluoroscopy have been markedly reduced due to radiation exposure and inability to depict transmural inflammation or extraluminal complications. Among the novel endoscopic tools, capsule endoscopy and balloon-assisted enteroscopy have tremendously opened new diagnostic and therapeutic perspectives, by allowing the direct visualization of small intestinal mucosa and, through enteroscopy, histological diagnosis as well as therapeutic interventions such as stricture dilation and bleeding treatment. These endoscopic techniques should always be preceded by imaging of the intestine in order to identify strictures. This review describes the most recent progress with the employment of novel imaging and endoscopic methodologies for investigating the small bowel in children with suspected or established Crohn's disease.

Magnetic resonance imaging (MRI) is increasingly used for disease activity grading in small bowel Crohn's disease. It is not known which imaging features are essential for grading. For further insight, we solicited the opinion of expert radiologists.

A questionnaire about the grading of Crohn's disease was sent to 36 radiologists who had published on MRI grading of Crohn's disease between January 2006 and January 2010. Radiologists were asked which MRI protocol they used, how they graded luminal Crohn's disease, which features they used, how important they considered those features for grading, and which reference standards they used.

Twenty-four radiologists responded (66%). They used different protocols and features; most frequently T2-weighted sequences (79%) and contrast enhanced fat saturated T1-weighted sequences (83%). MR-enterography was more often used than MR-enteroclysis (88% versus 33%). Features most frequently considered important for grading were bowel wall thickness (79% of radiologists), the presence of an abscess (75%), T1 enhancement (75%), and T1 stratification (46%). Reference standards differed; most commonly (ileo-) colonoscopy (88%) or surgery (75%) were used.

Bowel wall thickness, abscess, T1 enhancement and T1 stratification are most often used for grading. Because of difference in grading, there is need for an international consensus on MRI grading of Crohn's disease.

To prospectively assess dynamic contrast-enhanced (DCE-)MRI as compared to conventional sequences in patients with luminal Crohn's disease.

Patients with Crohn's disease undergoing MRI and ileocolonoscopy within 1 month had DCE-MRI (3T) during intravenous contrast injection of gadobutrol, single shot fast spin echo sequence and 3D T1-weighted spoiled gradient echo sequence, a dynamic coronal 3D T1-weighted fast spoiled gradient were performed before and after gadobutrol. Maximum enhancement (ME) and initial slope of increase (ISI) were calculated for four colon segments (ascending colon+coecum, transverse colon, descending colon+sigmoid, rectum) and (neo)terminal ileum. C-reactive protein (CRP), Crohn's disease activity index (CDAI), per patient and per segment Crohn's disease endoscopic index of severity (CDEIS) and disease duration were determined. Mean values of the (DCE-)MRI parameters in each segment from each patient were compared between four disease activity groups (normal mucosa, non-ulcerative lesions, mild ulcerative and severe ulcerative disease) with Mann-Whitney test with Bonferroni adjustment. Spearman correlation coefficients were calculated for continuous variables.

Thirty-three patients were included (mean age 37 years; 23 females, median CDEIS 4.4). ME and ISI correlated weakly with segmental CDEIS (r=0.485 and r=0.206) and ME per patient correlated moderately with CDEIS (r=0.551). ME was significantly higher in segments with mild (0.378) or severe (0.388) ulcerative disease compared to normal mucosa (0.304) (p<0.001). No ulcerations were identified at conventional sequences. ME correlated with disease duration in diseased segments (r=0.492), not with CDAI and CRP.

DCE-MRI can be used as a method for detecting Crohn's disease ulcerative lesions.

To evaluate fat saturated (fs) T2-weighted (w) fast relaxation fast spin echo (FRFSE)-sequences compared to the standard protocol with contrast agent for the evaluation of inflammatory activity in patients with Crohn's Disease (CD).

Fourty-eight patients (male, 17; female, 33; mean age, 37 years) with suspicion of inflammatory activity in proven CD who underwent MR enteroclysis (MRE) at 1.5T (GE Healthcare) were retrospectively included. Two blinded radiologists analyzed MRE images for presence and extent of CD lesions and degree of local inflammation for fsT2-w FRFSE and contrast enhanced T1-w images (T2-activity; T1-activity; score, 1-4) in consensus. Furthermore, mural signal intensity (SI) ratios (T2-ratio; T1-ratio) were recorded. Patient based MRE findings were correlated with endoscopic (45 patients), surgical (6 patients), histopathological, and clinical data (CDAI) as a surrogate reference standard.

In total, 24 of 48 eligible patients presented with acute inflammatory activity with 123 affected bowel segments. ROC analysis of the total inflammatory score presented an AUC of 0.93 (p<0.001) for T2-activity (T1-activity, AUC 0.63; p=0.019). ROC analysis revealed an AUC of 0.76 (p<0.001) for the T2-ratio (T1-ratio, AUC 0.51; p=0.93). General linear regression model revealed T2-activity (p=0.001) and age (p=0.024) as predictive factors of acute bowel inflammation.

T2-w FRFSE-sequences can depict CD lesions and help to assess the inflammation activity, even with improved accuracy as compared to contrast-enhanced T1-w sequences.

To evaluate the efficacy of MR enterography (MRE) in patients with known or suspected Crohn's disease without the use of anti-peristaltic pharmacologic agents compared to colonoscopy and histology.

A retrospective review of 850 consecutive patients who underwent routine MRE to evaluate known or suspected Crohn's disease was performed. Of these, 310 patients also underwent colonoscopy with biopsy(s) within 90 days. The results of the MRE were compared to the colonoscopy and pathology reports to determine the presence or absence of disease in evaluable bowel segments. Individual imaging parameters (including wall thickening, enhancement, T2 signal, mesenteric vascular prominence and adenopathy) were also separately analyzed to determine their independent predictive value.

In 310 patients, the overall sensitivity and specificity of MRE (using endoscopy as a gold standard) were 85% and 80% respectively (kappa=0.65). The sensitivity of MRE for detection of pathologically severe disease was 87% in the terminal ileum (TI) and 88% in the colon. In the subset of 162 patients who underwent colonoscopy within 30 days of MRE, the overall sensitivity remained 85% but the specificity increased to 85% (kappa=0.69). Wall thickening and abnormal enhancement were sensitive indicators of Crohn's disease (75% and 78%), while abnormal T2 signal, mesenteric vascular prominence and adenopathy were specific (86%, 91% and 93%).

MRE compares favorably to colonoscopy for evaluation of known or suspected Crohn's disease noninvasively and without the exposure to ionizing radiation associated with CT enterography (CTE).

To develop and validate a qualitative scoring system for enteric Crohn's disease activity using MR enterography (MRE).

MRE was performed in 16 patients (mean age 33, 8 male) undergoing small bowel resection. Mural thickness, T2 signal, contrast enhancement, and perimural oedema were scored qualitatively (0-3) at 44 locations. Transmural histopathological scoring of acute inflammation (AIS) was performed at all locations (score 0-13). MRI parameters best predicting AIS were derived using multivariate analysis. The MRI activity index was applied to 26 Crohn's patients (mean age 32, range 13-69 years, 15 male) and correlated to terminal ileal biopsy scores of acute inflammation ("eAIS" score 1-6). Receiver operator characteristic curves were calculated.

Mural thickness (coefficient 1.34 (95% CI 0.36, 2.32)], p=0.007) and T2 signal (coefficient 0.90 (95% CI -0.24, 2.04) p=0.06) best predicted AIS (AIS=1.79+1.34*mural thickness+0.94*mural T2 score [R-squared 0.52]). There was a significant correlation between the MRI index and eAIS (Kendall's tau=0.40, 95% CI 0.11-0.64, p=0.02). The model achieved a sensitivity of 0.81 (95% CI 0.54-0.96), specificity of 0.70 (0.35-0.93) and AUC 0.77 for predicting acute inflammation (eAIS ≥2).

A simple qualitative MRI Crohn's disease activity score appears predictive against a histopathological standard of reference.

Magnetic resonance enterography (MRE) and computed tomography enterography (CTE) visualizes small bowel Crohn's disease (CD) and its complications with high accuracy. The aim of this study was to determine the interobserver and intermodality agreement for detection of small bowel CD.

Fifty patients with suspected or known CD were included in the study and all patients underwent MRE and CTE on the same day. Four radiologists with experience in MRE and CTE techniques participated. Observers were blind to patient histories, results of ileocolonoscopies, and other small bowel examinations. Readers assessed the image quality, the presence of small bowel CD, and seven findings consistent with CD.

The image quality was better with CTE than MRE (P < 0.001) but the diagnostic yields were comparable (P = 0.4). For detection of small bowel CD, the interobserver agreement was substantial in CTE (κ = 0.64) and moderate in MRE (κ = 0.48). The intermodality agreement was fair to substantial (κ = 0.40-0.64) for different observers. Two abscesses were detected and confirmed at subsequent surgery. One abscess was not detected with MRE and only recorded by two observers in CTE. A total of 10 fistulas were detected: three were confirmed at subsequent surgery and four were false-positive findings.

MRE and CTE have comparable diagnostic yields in patients with suspected or known CD. However, CTE provides better image quality and interobserver agreement. In a substantial number of patients the diagnosis of small bowel CD is observer- and modality-dependent.

In the last decade, multiple imaging technologies have been developed that improve visualization of the mucosal, mural, and perienteric inflammation associated with inflammatory bowel diseases. Whereas these technologies have traditionally been used to detect and stage suspected enteric inflammation, we review new, emerging roles in detecting clinically occult inflammation (in asymptomatic patients) and inflammatory complications, predicting response prior to therapy, assessing response after therapy, and enteric healing. We compare the relative performance of these technologies in detecting inflammation, focusing on their advantages and disadvantages and how they might complement each other. We also discuss their potential benefits for patients and clinical trials, reviewing technologic developments and areas of research that could provide important insights into the pathophysiology of inflammatory bowel diseases-related enteric inflammation.

To highlight the advances in MRI of the small intestine in patients with Crohn's disease. MRI of the gut has become more feasible with improved spatial resolution and speed of the MR sequences allowing parallel evaluation for both disease activity and extra-enteric complications.

Recent literature highlights excellent diagnostic accuracy of MR enterography (MRE) that is comparable to computed tomography enterography (CTE). Compared to CTE the image quality is not quite as good, and there is slightly more interobserver variability in interpretation. Despite these performance characteristics, the overall diagnostic yield of MRE is comparable to CTE. The lack of radiation exposure related to MRE is a significant strength, especially in Crohn's population that by virtue of their younger age, body habitus and potential need for repeated imaging, is at highest risk of potential cancer from radiation exposure due to diagnostic imaging. MRE should not be viewed as a 'safer' version of a CTE. The physics of MRI allows the application of unique sequences that add novel insights not possible with other imaging modalities.

MRE is a highly effective technique for assessing Crohn's disease. We are only starting to explore new MRI sequences and the future of this technology is extremely exciting.

To derive an MRI score for assessing severity, therapeutic response and prognosis in acute severe inflammatory colitis.

Twenty-one patients with acute severe colitis underwent colonic MRI after admission and again (n = 16) after median 5 days of treatment. Using T2-weighted images, two radiologists in consensus graded segmental haustral loss, mesenteric and mural oedema, mural thickness, and small bowel and colonic dilatation producing a total colonic inflammatory score (TCIS, range 6-95). Pre- and post-treatment TCIS were compared, and correlated with CRP, stool frequency, and number of inpatient days (therapeutic response marker). Questionnaire assessment of patient worry, satisfaction and discomfort graded 1 (bad) to 7 (good) was administered

Admission TCIS correlated significantly with CRP (Kendall's tau=0.45, 95% confidence interval [CI] 0.11-0.79, p = 0.006), and stool frequency (Kendall's tau 0.39, 95% CI 0.14-0.64, p = 0.02). TCIS fell after treatment (median [22 range 15-31]) to median 20 [range 8-25], p = 0.01. Admission TCIS but not CRP or stool frequency was correlated with length of inpatient stay (Kendall's tau 0.40, 95% CI 0.11-0.69, p = 0.02). Patients reported some discomfort (median score 4) during MRI.

MRI TCIS falls after therapy, correlates with existing markers of disease severity, and in comparison may better predict therapeutic response.

To prospectively determine mural perfusion dynamics in patients with untreated celiac disease by using dynamic contrast material-enhanced magnetic resonance (MR) imaging and to compare these dynamics with those in a control population and in patients with celiac disease treated with a gluten-free diet.

Institutional review board approval and informed consent from all participants were obtained. Sixty consecutive patients with untreated celiac disease, 45 patients with celiac disease treated with a gluten-free diet for at least 1 year, and 30 control subjects were enrolled in this study. Dynamic contrast-enhanced MR imaging was performed by using a 1.5-T MR unit. For each MR imaging examination, maximum enhancement, slope of enhancement, and time-signal intensity curves were calculated at the level of the descending duodenal wall. Duodenal wall thickness was also evaluated. Statistical evaluation was performed by using one-way analysis of variance, and the results were confirmed by using the Bartlett test for equal variances and complemented by using Bonferroni multiple comparison, linear correlation, and the Student t test for paired data.

Mean maximum enhancement of the duodenal wall was significantly higher in patients with untreated celiac disease (229.1 +/- 46.4 [standard deviation]) than in patients with treated celiac disease (109.8 +/- 27.8) and control subjects (94.7 +/- 17.9) (P < .001 for each comparison). All 60 untreated patients showed a curve characterized by fast enhancement and washout (type 4), while all 45 treated patients and the 30 control subjects showed a curve characterized by slow constant enhancement (type 2). Mean duodenal wall thickness was not significantly different between untreated patients (2.2 mm +/- 0.4), treated patients (2.0 mm +/- 0.3), and control subjects (2.0 mm +/- 0.4) (one-way analysis of variance, P = .4177; Bartlett test, P = .6951).

The results of this study suggest that dynamic evaluation of the bowel wall by using contrast-enhanced MR imaging can be an effective and reproducible way to show the inflammation state in celiac disease.