CT Enterography: Concepts and Advances in Crohn's Disease Imaging

Machine learning methods in automated detection of CT enterography findings in Crohn's disease: A feasibility study

PURPOSE

Qualitative findings in Crohn's disease (CD) can be challenging to reliably report and quantify. We evaluated machine learning methodologies to both standardize the detection of common qualitative findings of ileal CD and determine finding spatial localization on CT enterography (CTE).

MATERIALS AND METHODS

Subjects with ileal CD and a CTE from a single center retrospective study between 2016 and 2021 were included. 165 CTEs were reviewed by two fellowship-trained abdominal radiologists for the presence and spatial distribution of five qualitative CD findings: mural enhancement, mural stratification, stenosis, wall thickening, and mesenteric fat stranding. A Random Forest (RF) ensemble model using automatically extracted specialist-directed bowel features and an unbiased convolutional neural network (CNN) were developed to predict the presence of qualitative findings. Model performance was assessed using area under the curve (AUC), sensitivity, specificity, accuracy, and kappa agreement statistics.

RESULTS

In 165 subjects with 29,895 individual qualitative finding assessments, agreement between radiologists for localization was good to very good (κ = 0.66 to 0.73), except for mesenteric fat stranding (κ = 0.47). RF prediction models had excellent performance, with an overall AUC, sensitivity, specificity of 0.91, 0.81 and 0.85, respectively. RF model and radiologist agreement for localization of CD findings approximated agreement between radiologists (κ = 0.67 to 0.76). Unbiased CNN models without benefit of disease knowledge had very similar performance to RF models which used specialist-defined imaging features.

CONCLUSION

Machine learning techniques for CTE image analysis can identify the presence, location, and distribution of qualitative CD findings with similar performance to experienced radiologists.

Local Assessment and Small Bowel Crohn's Disease Severity Scoring using AI

RATIONALE AND OBJECTIVES

We present a machine learning and computer vision approach for a localized, automated, and standardized scoring of Crohn's disease (CD) severity in the small bowel, overcoming the current limitations of manual measurements CT enterography (CTE) imaging and qualitative assessments, while also considering the complex anatomy and distribution of the disease.

MATERIALS AND METHODS

Two radiologists introduced a severity score and evaluated disease severity at 7.5 mm intervals along the curved planar reconstruction of the distal and terminal ileum using 236 CTE scans. A hybrid model, combining deep-learning, 3-D CNN, and Random Forest model, was developed to classify disease severity at each mini-segment. Precision, sensitivity, weighted Cohen's score, and accuracy were evaluated on a 20% hold-out test set.

RESULTS

The hybrid model achieved precision and sensitivity ranging from 42.4% to 84.1% for various severity categories (normal, mild, moderate, and severe) on the test set. The model's Cohen's score (κ = 0.83) and accuracy (70.7%) were comparable to the inter-observer agreement between experienced radiologists (κ = 0.87, accuracy = 76.3%). The model accurately predicted disease length, correlated with radiologist-reported disease length (r = 0.83), and accurately identified the portion of total ileum containing moderate-to-severe disease with an accuracy of 91.51%.

CONCLUSION

The proposed automated hybrid model offers a standardized, reproducible, and quantitative local assessment of small bowel CD severity and demonstrates its value in CD severity assessment.

Visceral adipose tissue volume effect in Crohn's disease using reduced exposure CT enterography

PURPOSE

The purpose of this investigation was to assess the effect of visceral adipose tissue volume (VA) on reader efficacy in diagnosing and characterizing small bowel Crohn's disease using lower exposure CT enterography (CTE). Secondarily, we investigated the effect of lower exposure and VA on reader diagnostic confidence.

METHODS

Prospective paired investigation of 256 CTE, 129 with Crohn's disease, were reconstructed at 100% and simulated 50% and 30% exposure. The senior author provided the disease classification for the 129 patients with Crohn's disease. Patient VA was measured, and exams were evaluated by six readers for presence or absence of Crohn's disease and phenotype using a 0-10-point scale. Logistic regression models assessed the effect of VA on sensitivity and specificity.

RESULTS

The effect of VA on sensitivity was significantly reduced at 30% exposure (odds radio [OR]: 1.00) compared to 100% exposure (OR: 1.12) (p = 0.048). There was no statistically significant difference among the exposures with respect to the effect of visceral fat on specificity (p = 0.159). The study readers' probability of agreement with the senior author on disease classification was 60%, 56%, and 53% at 100%, 50%, and 30% exposure, respectively (p = 0.004). When detecting low severity Crohn's disease, readers' mean sensitivity was 83%, 75%, and 74% at 100%, 50%, and 30% exposure, respectively (p = 0.002). In low severity disease, sensitivity also tended to increase as visceral fat increased (ORs per 1000 cm3 increase in visceral fat: 1.32, 1.31, and 1.18, p = 0.010, 0.016, and 0.100, at 100%, 50%, and 30% exposure).

CONCLUSIONS

While the interaction is complex, VA plays a role in detecting and characterizing small bowel Crohn's disease when exposure is altered, particularly in low severity disease.

Diagnosis and Classification of Inflammatory Bowel Disease Strictures

Intestinal strictures are a common complication in inflammatory bowel disease (IBD). Symptoms due to intestinal strictures range from mild bloating and/or abdominal discomfort to complete bowel obstruction. Careful selection of available medical, endoscopic, or surgical therapies is critical for optimizing patient outcomes and is dependent on the effective characterization of the stricture. This article will focus on the diagnosis and classification of IBD strictures.

Artificial Intelligence for Disease Assessment in Inflammatory Bowel Disease: How Will it Change Our Practice?

Artificial intelligence (AI) has arrived and it will directly impact how we assess, monitor, and manage inflammatory bowel disease (IBD). Advances in the machine learning methodologies that power AI have produced astounding results for replicating expert judgment and predicting clinical outcomes, particularly in the analysis of imaging. This review will cover general concepts for AI in IBD, with descriptions of common machine learning methods, including decision trees and neural networks. Applications of AI in IBD will cover recent achievements in endoscopic image interpretation and scoring, new capabilities for cross-sectional image analysis, natural language processing for automated understanding of clinical text, and progress in AI-powered clinical decision support tools. In addition to detailing current evidence supporting the capabilities of AI for replicating expert clinical judgment, speculative commentary on how AI may advance concepts of disease activity assessment, care pathways, and pathophysiologic mechanisms of IBD will be addressed.

COMPARATIVE ANALYSIS OF TWO ORAL CONTRAST AGENT VOLUMES FOR COMPUTED TOMOGRAPHY ENTEROGRAPHY IN CROHN'S DISEASE PATIENTS

BACKGROUND

Crohn's disease (CD) is an inflammatory bowel disease characterized by a chronic and recurrent inflammation of the gastrointestinal tract caused by an interaction of genetic and environmental factors.

OBJECTIVE

To compare the quality and acceptance of two different oral contrast volumes for computed tomography enterography in Crohn's disease patients.

METHODS

A cross-sectional study was conducted in 58 consecutive Crohn's disease patients who randomly received an oral contrast agent composed of 78.75 g polyethylene glycol diluted in either 1,000 mL or 2,000 mL of water. An examination was performed to evaluate the presence of inflammation or complications in the small bowel. The variables included the quality of intestinal segment filling and luminal distension, and oral contrast agent acceptance and tolerance in the patients. Statistical analysis included descriptive statistics and association tests.

RESULTS

A total of 58 patients were assessed, in which 58.6% were female, 34.5% exhibited clinically-active disease, and 63.8% were receiving biologic therapy. As for comparative analysis between the two different volumes of oral contrast, no statistically significant difference was found regarding bowel loop filling (P=0.58) and adequate luminal distension (P=0.45). Patients who received a larger volume (2,000 mL) exhibited side-effects more frequently (51.7% vs 31.0%; P=0.06) and had greater difficulty ingesting the agent (65.5% vs 37.9%; P=0.07) compared with a volume of 1,000 mL.

CONCLUSION

The quality of computed tomography enterography was not influenced by the contrast volume. However, acceptance and tolerance were better in the 1,000 mL group.

Colonic strictures in children and young adults with Crohn's disease: Recognition on MR enterography

OBJECTIVES

Identify MRE features of colonic strictures in children/young adults with Crohn's disease.

METHODS

Included are patients with colonic strictures on colonoscopy imaged with MRE. Bowel wall thickening (BWT) with luminal narrowing, pre-stenotic dilatation (PSD), bowel wall enhancement, and diffusion restriction were evaluated.

RESULTS

All potential strictures (n=12) had BWT with luminal narrowing on MRE. 8/12 had PSD, meeting our MRE stricture criteria. MRE diagnosed 8/12 colonic strictures compared to colonoscopy but was concordant with findings in all surgical patients.

CONCLUSION

Strictures on MRE did not always agree with colonoscopy, but when correlating with surgery, MRE findings were all concordant.

Identification of the distinguishing features of Crohn's disease and ischemic colitis using computed tomographic enterography

Background and aims: The differential diagnosis between Crohn’s disease (CD) and ischemic colitis (ISC) is important as their clinical management is different. ISC can easily be misdiagnosed as CD, especially in elderly populations. The distinctive radiographic features of the two disease entities have not been investigated. The aim of this study is to assess the utility of computed tomographic enterography (CTE) in the differential diagnosis between CD and ISC.

Methods: Patients with confirmed CD and ISC were identified through an electronic medical record search of the Cleveland Clinic Foundation. Patients who had undergone CTE, with or without concurrent colonoscopy and histopathological specimens, were included in this study. CTE images were blindly re-reviewed by an expert gastrointestinal radiologist. The sensitivities, specificities, accuracies and positive and negative predictive values for each of the CTE findings in differentiating CD from ISC were estimated. Kappa coefficients (κ) were calculated to measure diagnosis agreement between CTE and the reference standard.

Results: A total of 34 eligible patients were included in this study with 17 having CD and 17 having ISC. In differentiating CD from ISC, the presence of mucosal hyperenhancement and absence of the “target sign” on CTE showed a sensitivity of 100% each for CD, while the two radiographic features yielded a low specificity of 35.3% and 76.5%, respectively. The presence of stricture had a lower sensitivity of 64.7% for the detection of CD but had a high specificity of 100%. In distinguishing CD from ISC, the accuracy of presence of mucosal hyperenhancement, stricture and absence of target sign were 67.7%, 82.4% and 88.2%, respectively. The combination of the presence of mucosal hyperenhancement and the absence of the target sign achieved an accuracy of 100% for distinguishing CD from ISC. There was a good correlation between CTE and the reference standard for distinguishing CD from ISC (κ = 0.882).

Conclusions: CTE appeared to be clinically useful in distinguishing CD from ISC.

MDCT findings in small bowel obstruction: implications of the cause and presence of complications on treatment decisions

Small bowel obstruction (SBO) accounts for a considerable proportion of emergency room visits, inpatient admissions, and surgical interventions in the United States. Multi-detector computed tomography (MDCT) plays a key role in imaging patients presenting with acute symptoms suggestive of SBO, which helps in establishing the diagnosis, elucidating the cause of obstruction, and detecting complications, such as ischemia or frank bowel necrosis and perforation. Recently, management of patients with SBO has shifted toward a more conservative approach with supportive care and nasogastric tube decompression, as the obstruction in many cases can resolve spontaneously without the need for operative intervention. However, management decisions in SBO remain notoriously difficult, relying on a combination of clinical, laboratory, and imaging factors to help stratify patients into conservative or surgical treatment. Imaging is often an important factor assisting in the decision-making process since traditional clinical signs of vascular compromise, such as acidosis, fever, leukocytosis, and tachycardia are often unreliable in predicting the need for operative intervention. Thus, it is critically important for radiologists to identify imaging features that suggest or indicated high likelihood of bowel vascular compromise in order to help optimize management prior to the development of bowel ischemia and eventually necrosis. By excluding signs of potentially ischemic or necrotic bowel on MDCT, patients may be spared unnecessary surgery, thus decreasing postsurgical complications and averting potential increase for the risk of future SBO and repeated surgery. Conversely, if imaging features indicate potential vascular compromise of the bowel wall that may lead to bowel ischemia, urgent surgical intervention may prevent progression to bowel necrosis and subsequent perforation.

Value of Computerized Tomography Enterography in Predicting Crohn's Disease Activity: Correlation with Crohn's Disease Activity Index and C-Reactive Protein

Background

The accurate evaluation of Crohn’s disease activity is important for the treatment of the disease and for monitoring the response. Computerized tomography (CT) enterography is a useful imaging modality that reflects enteric inflammation, as well as extramural complications.

Objectives

The aim of this study was to evaluate the correlation between CT enterographic (CTE) findings of active Crohn’s disease and the Crohn’s disease activity index (CDAI) and C-reactive protein (CRP).

Patients and Methods

Fifty CT enterographies of 39 patients with Crohn’s disease in the small bowel were used in our study. The CDAI was assessed through clinical and laboratory variables. Multiple CT parameters, including mural hyperenhancement, mural thickness, mural stratification, comb sign, and mesenteric fat attenuation, were evaluated with a four-point scale. The presence or absence of enhanced lymph nodes, fibrofatty proliferation, sinus or fistula, abscess, and stricture were also assessed. Two gastrointestinal radiologists independently reviewed all CT images, and inter-observer agreement was examined. Correlations between CT findings, CRP, and CDAI were assessed using Spearman’s rank correlation and logistic regression analysis. To assess the predictive accuracy of the model, a receiver-operating characteristic curve analysis for the sum of CT enterographic scores was used.

Results

Mural hyperenhancement, mural thickness, comb sign, mesenteric fat density, and fibrofatty proliferation were significantly correlated with CDAI and CRP (P < 0.05). The binary logistic regression model demonstrated that mesenteric fat density, mural stratification, and the presence of enhanced lymph nodes (P < 0.05) had an influence on CDAI severity. The area under the receiver operating characteristic curve (AUROC) of the CTE index for predicting disease activity was 0.85. Using a cut-off value of 8, the sensitivity and negative predictive values were 95% and 94%, respectively.

Conclusion

Most CTE findings correlated with CDAI and CRP in patients with active Crohn’s disease.

Crohn's disease Activity: Abdominal Computed Tomography Histopathology Correlation

Purpose

Crohn’s disease is a type of inflammatory bowel disease affecting estimated 4 million people worldwide. Therapy stratification of Crohn’s disease (CD) is mainly based on the inflammatory activity being assessed by endoscopic biopsy and clinical criteria. Cross-sectional imaging allows for the assessment of structural characteristics of the entire gastrointestinal tract including small bowel loops and may provide potential non-invasive image-based biomarkers for the inflammatory activity of CD. The aim of this study was to explore the predictive value of Computed Tomography-based morphologic patterns for inflammatory activity in CD.

Material and methods

42 patients diagnosed with CD were included in a retrospective study (13 male, 29 female, median age 32 years). Abdominal CT imaging was carried out on symptomatic patients at a single institution 0–10 days prior to endoscopic biopsy or surgery using a protocol optimized for the characterization of structural bowel alterations. Image data were initially reviewed independently by three radiologists and discrepancies were settled in consensus with a focus on mesenteric fat stranding and combing, mesenteric adenopathy, mesenteric abscess, intraperitoneal free fluid, fistula, skip lesions, highest wall thickness and the localization of the affected bowel. The extent of inflammatory activity in the bowel wall was determined subsequently by histological analysis.

Results

All intestinal and extraintestinal CT findings except the mesenteric comb sign showed a tendency towards higher extent or prevalence in patients with high histological inflammatory activity score, especially median bowel wall thickness (6.0 mm vs. 3.5 mm), mesenteric abscesses (32% vs. 0%) and mesenteric adenopathy (94% vs. 45%). Spearman rank order correlation coefficient indicated a significant correlation of bowel wall thickness (r = 0.40, p < 0.05), mesenteric adenopathy (r = 0.54, p < 0.05), mesenteric abscess (r = 0.33, p < 0.05) and mesenteric fat stranding (r = 0.33, p < 0.05) with the histological inflammatory activity score.

Conclusion

CT-based biomarkers including wall thickness, mesenteric fat stranding, mesenteric lymphadenopathy and mesenteric abscess positively correlated with the histological inflammatory activity score and therefore provided additional information for therapy stratification in symptomatic patients with CD, particularly as most of these biomarkers are hidden from endoscopy.

Observer performance for adaptive, image-based denoising and filtered back projection compared to scanner-based iterative reconstruction for lower dose CT enterography

PURPOSE

The purpose of this study was to compare observer performance for detection of intestinal inflammation for low-dose CT enterography (LD-CTE) using scanner-based iterative reconstruction (IR) vs. vendor-independent, adaptive image-based noise reduction (ANLM) or filtered back projection (FBP).

METHODS

Sixty-two LD-CTE exams were performed. LD-CTE images were reconstructed using IR, ANLM, and FBP. Three readers, blinded to image type, marked intestinal inflammation directly on patient images using a specialized workstation over three sessions, interpreting one image type/patient/session. Reference standard was created by a gastroenterologist and radiologist, who reviewed all available data including dismissal Gastroenterology records, and who marked all inflamed bowel segments on the same workstation. Reader and reference localizations were then compared. Non-inferiority was tested using Jackknife free-response ROC (JAFROC) figures of merit (FOM) for ANLM and FBP compared to IR. Patient-level analyses for the presence or absence of inflammation were also conducted.

RESULTS

There were 46 inflamed bowel segments in 24/62 patients (CTDIvol interquartile range 6.9-10.1 mGy). JAFROC FOM for ANLM and FBP were 0.84 (95% CI 0.75-0.92) and 0.84 (95% CI 0.75-0.92), and were statistically non-inferior to IR (FOM 0.84; 95% CI 0.76-0.93). Patient-level pooled confidence intervals for sensitivity widely overlapped, as did specificities. Image quality was rated as better with IR and AMLM compared to FBP (p < 0.0001), with no difference in reading times (p = 0.89).

CONCLUSIONS

Vendor-independent adaptive image-based noise reduction and FBP provided observer performance that was non-inferior to scanner-based IR methods. Adaptive image-based noise reduction maintained or improved upon image quality ratings compared to FBP when performing CTE at lower dose levels.

CT enterography: technical and interpretive pitfalls

CT enterography is a first-line test at many institutions to investigate potential small bowel disorders. While numerous articles have focused on the ability of CT enterography to diagnose and stage Crohn's disease, small bowel neoplasia, and malabsorptive or vascular disorders, this article reviews CT enterography limitations, technical and interpretive pitfalls, image review tactics, and complementary radiologic and endoscopic examinations to improve diagnostic accuracy. CT enterography limitations include its inability to demonstrate isolated mucosal abnormalities such as aphthous ulcers and its use of ionizing radiation. The most common technical pitfall of CT enterography is inadequate small bowel distention resulting from inadequate ingestion, gastric retention, or rapid small bowel transit of a large volume of neutral enteric contrast material. Additionally, segments of jejunum are frequently collapsed. Interpretive pitfalls commonly result from peristaltic contractions, transient intussusception and opaque intraluminal debris. Opaque debris is especially problematic during multiphasic CT enterography performed to identify potential small bowel sources of obscure gastrointestinal bleeding. False-negative examinations may result from inadequate radiation dose. Examinations complementary to CT enterography include small bowel follow through, enteroclysis, CT enteroclysis, MR enterography, MR enteroclysis, capsule endoscopy, and balloon-assisted endoscopy. Properly performed and accurately interpreted CT enterography contributes to the diagnosis and management of small bowel disease by itself and as a complement to other radiologic and optical small bowel imaging examinations.

CT enterography: Diagnostic value of 4th generation iterative reconstruction algorithm in low dose studies in comparison with standard dose protocol for follow-up of patients with Crohn's disease

PURPOSE

To compare radiation dose, image quality and diagnostic performance of low dose CT enterography (CTE) protocol combined with iterative reconstruction algorithm (iDose(4)) with standard dose CTE in follow-up of patients with known Crohn's disease (CD).

MATERIALS AND METHOD

Thirty-six patients (12 females), with CD underwent a low-dose CTE scan during single venous phase on 256 MDCT scanner, with the following parameters: 120 kV, automated mAs dose-modulation, slice thickness 2mm and iDose(4) iterative reconstruction algorithm. A control group of thirty-seven patients underwent standard dose CTE examination on the same CT scanner. Two radiologists, blinded to clinical and pathological findings, independently evaluated in each scan, HU values in bowel wall and any presence of CD activity features and disease complications. Image noise and diagnostic quality were evaluated using a 4-point scale. Dose-length product (DLP) and CT-dose-index (CTDI) were recorded and data from both examinations were compared and statistically analyzed.

RESULTS

Low-dose CTE protocol showed high diagnostic quality in assessment of Crohn's disease obtaining significantly (p ≤ 0.001) lower values of DLP and CTDI (604.98 mGy*cm and 12.29 mGy) as compared to standard dose examinations (974.85 mGy*cm and 19.71 mGy), with an overall dose reduction of 37.6%. Noise resulted slightly higher in iDose(4) images (SD=15.97) than in standard dose ones (SD=13.61) but this difference was not statistically significant (p=0.064).

CONCLUSION

Low-dose CTE combined with iDose(4) reconstruction algorithm offers high quality images with significant reduction of radiation dose, and therefore can be considered a useful tool in the management of CD patients, considering their young age and the frequent imaging follow-up required.

Review article: optimal preparation for surgery in Crohn's disease

BACKGROUND

One-third of Crohn's disease (CD) patients will undergo abdominal surgery within the first 5 years of diagnosis.

AIM

To review the available evidence on pre-operative optimisation of CD patients.

METHODS

The literature regarding psychological support, radiological imaging, abdominal abscess management, nutritional support, thromboembolic prophylaxis and immunosuppression in the perioperative setting was reviewed.

RESULTS

For diagnosis of fistulas, abscesses and stenosis, ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI) have a high diagnostic accuracy. Under either CT or US guidance, it is possible to perform abscess percutaneous drainage (PD), which, with systemic antibiotic therapy, should be the first-line approach to intra-abdominal abscesses. CD patients with weight loss <10% within the last 3-6 months, body mass index < 18.5 kg/m(2) and/or albumin levels <30 g/L, are at an increased risk of post-operative complications. Pre-operative nutritional support should be used in these patients. IBD patients undergoing surgery have a higher risk of venous thromboembolic disease than patients with colorectal cancer, and current guidelines recommend that they should receive prophylaxis with heparin. Whether the use of anti-TNF agents before surgery increases the likelihood of post-operative complications, is the subject of much debate. To date, cumulative evidence from most studies (all retrospective) suggests that there is no such risk increment. Prospective studies are necessary to firmly establish this conclusion.

CONCLUSIONS

Preparation for surgery requires close interaction between surgeons, gastroenterologist, radiologists, psychologists and the patient. Correct pre-operative planning of surgical treatment has a major impact on the outcome of such treatment.

Intestinal wall thickness detected by multidetector spiral computed tomography enterography predicts the disease severity of Crohn's disease

OBJECTIVE

Multidetector spiral computed tomography enterography (MSCTE) and ileocolonoscopy are used in evaluating inflammatory situation of Crohn's disease (CD) patients. The purpose of this study was to determine the disease severity of CD patients by combining the intestinal wall thickness by MSCTE with ileocolonoscopy.

MATERIAL AND METHODS

This retrospective study included 50 patients with terminal ileal CD. Diagnosis was confirmed based on clinical features, endoscopy, and pathology. Patients underwent both MSCTE and ileocolonoscopy. Ileal wall thickness was measured and the disease severity was evaluated by CD activity index (CDAI). Intestinal mucosal lesions were scored by the simple endoscopic score for CD (SES-CD).

RESULTS

Of the 50 patients with active terminal ileal CD, the comparison of scores between SES-CD and CDAI showed significant association with Spearman's rank correlation coefficient (p < 0.01). There were statistically significant correlation between the wall thickness and the SES-CD (p < 0.0001) as well as CDAI (p < 0.001), respectively, but no significant correlation between the wall thickness and the C-reactive protein (CRP) was found (p = 0.43). Moreover, we found that the wall thickness was preferential to predict the disease severity in the terminal ileal CD.

CONCLUSION

MSCTE, in combination with ileocolonoscopy, is reliable to identify disease severity in CD patients and provides more accurate information in the diagnosis and treatment.

Diagnostic imaging in Crohn's disease: what is the new gold standard?

Historically Barium and isotope studies been used for imaging of inflammatory bowel disease (IBD) but carry risk of radiation exposure. Use of Barium is declining resulting in fewer radiologists that have the necessary expertise. Isotopes studies lack anatomical definition but 18F - fludeoxyglucose (FDG) positron emission tomography (PET) shows promise in accurate assessment of disease compared to endoscopy. Computerised tomography (CT) is particularly useful in assessment of complications of Crohn's disease (CD) but radiation exposure is high. CT enterography (CTE) has improved visualisation of small bowel mucosal disease and allows assessment of disease activity. Ultrasound is increasingly used for preliminary assessment of patients with potential IBD. Although widely available and economically attractive, the expertise required is not widespread. Finally magnetic resonance imaging (MRI) is proving to be the most accurate tool for assessment of disease extent and distribution. MRI of the pelvis has superseded other techniques in assessment of peri-anal fistulation.

Imaging Crohn disease: MR enterography

Magnetic resonance enterography in Crohn disease management has been rapidly growing in importance during recent years. Being familiar to this technique is essential for radiologists and also, to some extent, for gastroenterologists. Our aim is to study and describe the imaging findings in magnetic resonance enterography in Crohn disease to develop a comprehensive and useful review article and imaging atlas.

CT enterography as a powerful tool for the evaluation of inflammatory activity in Crohn's disease: relationship of CT findings with CDAI and acute-phase reactants

PURPOSE

Few studies have correlated computed tomography enterography (CTE) findings with Crohn's disease (CD) clinical and biochemical activity. The aim of this study was to evaluate correlations between CTE findings with CD activity.

MATERIALS AND METHODS

The CTE datasets from 62 patients were retrospectively reviewed for different parameters: bowel wall thickening and hyperenhancement, mesenteric alterations, abdominal free fluid and complications related to the disease (fistulas, strictures, abscesses). Activity was assessed using the Crohn's Disease Activity Index (CDAI) and some biochemical markers (C-reactive protein, erythrocyte sedimentation rate, alpha 2-globulins, fibrinogen, platelets, haemoglobin). Correlations between CTE parameters, clinical activity score and laboratory parameters were assessed by logistic regression.

RESULTS

CDAI was significantly correlated with increased fat density (p = 0.03) and intestinal strictures (p = 0.04). Platelet counts were elevated in patients with enlarged mesenteric lymph nodes (p = 0.009) and the comb sign (p = 0.05). Serum alpha 2-globulins were higher in the presence of the comb sign (p = 0.03).

CONCLUSION

The CTE finding of perienteric inflammation (increased fat density) and vascular engorgement of the vasa recta in CD patients suggest that the disease is clinically active and that these patients may require more aggressive treatment than patients without these findings.

Endoscopic therapy in inflammatory bowel diseases (with videos)

Endoscopic therapies are important modalities in the treatment of IBD, adjunct to medical and surgical approaches. These therapeutic techniques are particularly useful in the management of IBD-associated or IBD surgery–associated strictures, fistulas, and sinuses and colitis-associated neoplasia. Although the main focus of endoscopic therapies in IBD has been on balloon stricture dilation and ablation of adenoma-like lesions, new endoscopic approaches are emerging, including needle-knife stricturotomy, needle-knife sinusotomy, endoscopic stent placement, and fistula tract injection. Risk management of endoscopy-associated adverse events is also evolving. The application of endoscopic techniques in novel ways in the treatment of IBD is just beginning and will likely expand rapidly in the near future.

CT enterography of Crohn's disease

CT enterography (CTE) is a technique using neutral oral contrast, intravenous contrast and thin cut, multiplanar CT acquisitions to optimize small bowel imaging. One of the primary indications for CTE is the detection and evaluation of Crohn's disease. This article summarizes the advantages/disadvantages, scanning technique, imaging findings, performance and pitfalls of CTE for the evaluation of Crohn's disease.