CT enterography of Crohn's disease

Multimodality Imaging of Small Bowel Crohn Disease

Computed tomography enterography, magnetic resonance enterography, and bowel ultrasound are complementary tools central to diagnosing and monitoring Crohn disease. These modalities can identify active inflammation, penetrating, and stricturing disease. Crohn disease must be monitored frequently to guide therapy, and resolution of inflammation on imaging correlates directly with steroid-free clinical remission. While disease activity assessment is qualitative, newer quantitative techniques to assess active inflammation are emerging. These as well as other techniques, such as contrast-enhanced ultrasound (US) and US elastography, will offer new tools for future radiologists.

Measurements on slope parameter mapping based on dual-energy CT enterography for improving Crohn's disease diagnosis and inflammatory activity evaluation

To explore the value of slope parameter images (SPI) derived from the dual-phase dual-energy CT enterography (DE-CTE) in the diagnosis and activity evaluation of Crohn's disease (CD). A retrospective analysis of 76 patients with CD and 53 controls who underwent dual-phase DE-CTE between January 2019 and March 2022. CD lesions were divided into non-moderate-to-severe activity (n = 108) and moderate-to-severe activity (n = 59). Virtual monoenergetic images of 40-100 keV and SPI for energy spectrum curves between 40 and 100 keV (SPI40-100) were generated. Virtual monoenergetic CT values (HU40-100keV) and the slope between 40 and 100 keV measured on SPI40-100 (SP40-100) on intestinal wall and adjacent mesenteric fat for the dual phases were collected. The performances of quantitative parameters in the diagnosis and activity assessment of CD were evaluated. The dual-phase SP40-100 and HU40-100 in the affected intestinal wall and adjacent mesenteric fat were higher than those in the control group (P < 0.001). For CD diagnosis, the area under the curve (AUC) of the arterial phase (AP) SP40-100 of mesenteric fat was the highest (AUC = 0.969, P < 0.05). The dual-phase SP40-100 and HU40-100keV of the intestinal wall and creeping fat in those with moderate-to-severe activity were significantly higher than those with non-moderate-to-severe activity (P < 0.001). For activity assessment, AP-SP40-100 of creeping fat had the highest AUC among all parameters (AUC = 0.935, P < 0.05). The measurements on SPI40-100 obtained via dual-phase DE-CTE have high value in CD diagnosis and inflammatory activity evaluation, and the AP SP40-100 of mesenteric fat has the highest diagnostic efficacy.

EANM/SNMMI guideline/procedure standard for [18F]FDG hybrid PET use in infection and inflammation in adults v2.0

INTRODUCTION

Hybrid [18F]FDG PET imaging is currently the method of choice for a wide variety of infectious and inflammatory disorders and was recently adopted in several clinical guidelines. A large amount of evidence-based articles, guidelines and appropriate use criteria have been published since the first version of this guideline in 2013.

PURPOSE

To provide updated evidence-based information to assist physicians in recommending, performing and interpreting hybrid [18F]FDG PET examinations for infectious and inflammatory disorders in the adult population.

METHODS

A systematic literature search of evidence-based articles using whole-body [18F]FDG hybrid imaging on the indications covered within this guideline was performed. All systematic reviews and meta-analyses published within the last 10 years until January 2023 were identified in PubMed/Medline or Cochrane. For each indication covered in this manuscript, diagnostic performance was provided based on meta-analyses or systematic reviews. If not available, results from prospective or retrospective studies were considered based on predefined selection criteria. RESULTS AND CONCLUSIONS: Hybrid [18F]FDG PET is extremely useful in the work-up and management of adults with infectious and inflammatory diseases, as supported by extensive and rapidly growing evidence-based literature and adoption in clinical guidelines. Practical recommendations are provided describing evidence-based indications as well as interpretation criteria and pitfalls. Monitoring treatment response is the most challenging but insufficiently studied potential application in infection and inflammation imaging.

Computed Tomography and Magnetic Resonance Enterography: From Protocols to Diagnosis

Both Magnetic Resonance Enterography (MRE) and Computed Tomography Enterography (CTE) are crucial imaging modalities in the diagnosis and treatment of inflammatory bowel disease (IBD). CTE is often used in acute scenarios, such as when complications (such as abscesses, perforations, or bowel obstructions) are suspected. It can also help determine the degree and extent of pathological processes. Although CTE is rapid, generally accessible, and offers precise images that are useful in emergencies, it does expose patients to ionizing radiation. Nevertheless, MRE is very useful in assessing perianal illness and the small intestine, and it is frequently used in patients who need repeated follow-ups or are pregnant to minimize radiation exposure. Moreover, MRE can demonstrate oedema, fistulas, abscesses, and the thickening of the bowel wall. In addition, MRE offers superior soft tissue contrast resolution without ionizing radiation, which helps identify complications such as fistulas and abscesses. With their respective advantages and disadvantages, both approaches play essential roles in assessing IBD. The primary goal of this review is to provide an overview of the technical specifications, benefits, drawbacks, and imaging findings of CTE and MRE.

The Current Role of Imaging in the Diagnosis of Inflammatory Bowel Disease and Detection of Its Complications: A Systematic Review

Inflammatory bowel disease (IBD) encompasses complex gastrointestinal (GI) conditions, primarily Crohn's disease (CD) and ulcerative colitis (UC), requiring precise imaging for effective diagnosis and management of complications. This systematic review aimed to evaluate the current role of imaging modalities in diagnosing IBD and detecting related complications. The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We performed a literature search using text words and controlled vocabulary applying Boolean operators "AND," "OR," with various combinations on databases such as PubMed, Embase, and Cochrane Library. The search targeted open-access articles involving humans, with full-text available, and published in the English Language from 2005 to 2024. The quality of the included studies was assessed using the Cochrane Risk-of-Bias (RoB) checklist. Our search process identified 127 records from Cochrane (39), Embase (29), and PubMed (59). After removing 98 irrelevant records, 29 underwent further screening. Five were excluded as they involved irrelevant problems or outcomes, leaving us with 24 reports with full text, all of which were accessible. Following the eligibility assessment, two more reports were excluded due to inaccessibility, and 22 studies were included in the final analysis. The risk of bias and methodological quality assessment revealed that out of 22 studies analyzed, five (23%) had a high risk of bias, while 13 (59%) were classified as moderate risk, and four (18%) showed low risk. This distribution highlights a predominance of moderate-risk studies in research on imaging in IBD, emphasizing the need for enhanced study designs in future investigations. Our findings revealed the varying effectiveness of imaging modalities in diagnosing complications of CD and UC. Magnetic resonance enterography (MRE) stands out as the preferred method for CD due to its high sensitivity and noninvasive nature. In contrast, colonoscopy remains the gold standard for UC, providing direct visualization of mucosal lesions. While techniques like ultrasound and capsule endoscopy offer valuable insights, they have limitations that may affect their utility in certain cases.

Endoscopic Skipping, Stricturing, and Penetrating Complications in Crohn's Disease on Tandem Ileo-colonoscopy and Cross-sectional Imaging: A Retrospective Cohort Study

BACKGROUND

Crohn's disease (CD) is characterized by discontinuous inflammation. Failure to identify skipping lesions of the terminal ileum (TI) or transmural changes can lead to incorrect management.

METHODS

Eligible adult patients with CD undergoing ileo-colonoscopy and computed tomography enterography or magnetic resonance enterography within 6 months. We determined the prevalence of endoscopic skipping (normal ileum on colonoscopy but proximal small bowel inflammation on cross-sectional imaging), skip lesions (discontinuous inflammation along the gastrointestinal tract identified on cross-sectional imaging), structuring, and penetrating complications.

RESULTS

Among 202 patients, 45 (22.3%) had endoscopic skipping proximal to TI intubation. Fifty patients (24.5%) had small bowel skip lesions, primarily in the ileum. Strictures were identified in 34 patients (16.8%) through both imaging and ileo-colonoscopy, in 21 patients (10.4%) solely through cross-sectional imaging, and in 3 patients (1.5%) solely through ileo-colonoscopy. Approximately 36.2% of stricturing cases would be missed without cross-sectional imaging. Penetrating complications, including abscesses (2.5%) and various fistula types (4.9%), were detected in 15 (7.4%) patients.

CONCLUSIONS

Ileo-colonoscopy missed detection of active CD in approximately one-fifth of cases due to more proximal disease location. Stricturing disease might be missed in more than a third of cases if cross-sectional imaging is not performed.

Individualized small bowel preparation for computed tomography enterography: A prospective randomized controlled trial

BACKGROUND AND AIM

The study aims to evaluate the feasibility of body mass index (BMI)-based individualized small bowel preparation for computed tomography enterography (CTE).

METHODS

In this prospective randomized controlled study, patients undergoing CTE were randomly assigned to the individualized group or standardized group. Those in individualized group were given different volumes of mannitol solution based on BMI (1000 mL for patients with BMI < 18.5 kg/m2, 1500 mL for patients with 18.5 kg/m2 ≤ BMI < 25 kg/m2 and 2000 mL for patients with BMI ≥ 25 kg/m2) while patients in the standardized group were all asked to consume 1500-mL mannitol solution. CTE images were reviewed by two experienced radiologists blindly. Each segment of the small bowel was assessed for small bowel image quality and disease detection rates. Patients were invited to record a diary regarding adverse events and acceptance.

RESULTS

A total of 203 patients were enrolled and randomly divided into two groups. For patients with BMI < 18.5 kg/m2, 1000-mL mannitol solution permitted a significantly lower rate of flatulence (P = 0.045) and defecating frequency (P = 0.011) as well as higher acceptance score (P = 0.015), but did not affect bowel image quality and diseases detection compared with conventional dosage. For patients with BMI ≥ 25 kg/m2, 2000-mL mannitol solution provided better overall image quality (P = 0.033) but comparable rates of adverse events and patients' acceptance compared with conventional dosage.

CONCLUSIONS

Individualized bowel preparation could achieve both satisfactory image quality and patients' acceptance thus might be an acceptable alternative in CTE.

Duodenal Crohn's disease: Case report and systematic review

BACKGROUND

Inflammatory bowel disease, including ulcerative colitis, microscopic colitis, and Crohn's disease (CD), has a global impact. This review focuses on duodenal CD (DCD), a rare subtype affecting the duodenum. DCD's rarity and asymptomatic nature create diagnostic challenges, impacting prognosis and patient well-being. Delayed diagnosis can worsen DCD outcomes.

AIM

To report a rare case of DCD and to discuss the diagnostic challenges and its implications on prognosis.

METHODS

A systematic literature search, following the PRISMA statement, was conducted. Relevant studies were identified and analysed using specific Medical Subject Terms (MeSH) from PubMed/MEDLINE, American Journal of Gastroenterology, and the University of South Wales database. Data collection included information from radiology scans, endoscopy procedures, biopsies, and histopathology results.

RESULTS

The review considered 8 case reports and 1 observational study, involving 44 participants diagnosed with DCD, some of whom developed complications due to delayed diagnosis. Various diagnostic methods were employed, as there is no gold standard workup for DCD. Radiology scans [magnetic resonance imaging (MRI), computed tomography (CT), and upper gastrointestinal X-ray], endoscopy procedures (colonoscopy and esophagogastroduodenoscopy), biopsies, and clinical suspicions were utilized.

CONCLUSION

This review discusses DCD diagnosis challenges and the roles of CT, MRI, and fluoroscopy. It notes their limitations and compares findings with endoscopy and histopathology studies. Further research is needed to improve diagnosis, emphasizing scan interpretation, endoscopy procedures, and biopsies, especially in high-risk patients during routine endoscopy.

Radiological biomarkers reflecting visceral fat distribution help distinguish inflammatory bowel disease subtypes: a multicenter cross-sectional study

OBJECTIVES

To achieve automated quantification of visceral adipose tissue (VAT) distribution in CT images and screen out parameters with discriminative value for inflammatory bowel disease (IBD) subtypes.

METHODS

This retrospective multicenter study included Crohn's disease (CD) and ulcerative colitis (UC) patients from three institutions between 2012 and 2021, with patients with acute appendicitis as controls. An automatic VAT segmentation algorithm was developed using abdominal CT scans. The VAT volume, as well as the coefficient of variation (CV) of areas within the lumbar region, was calculated. Binary logistic regression and receiver operating characteristic analysis was performed to evaluate the potential of indicators to distinguish between IBD subtypes.

RESULTS

The study included 772 patients (365 CDs, median age [inter-quartile range] = 31.0. (25.0, 42.0) years, 255 males; 241 UCs, 46.0 (34.0, 55.5) years, 138 males; 166 controls, 40.0 (29.0, 53.0) years, 80 males). CD patients had lower VAT volume (CD = 1584.95 ± 1128.31 cm3, UC = 1855.30 ± 1326.12 cm3, controls = 2470.91 ± 1646.42 cm3) but a higher CV (CD = 29.42 ± 15.54 %, p = 0.006 and p ˂ 0.001) compared to UC and controls (25.69 ± 12.61 % vs. 23.42 ± 15.62 %, p = 0.11). Multivariate analysis showed CV was a significant predictor for CD (odds ratio = 6.05 (1.17, 31.12), p = 0.03). The inclusion of CV improved diagnostic efficiency (AUC = 0.811 (0.774, 0.844) vs. 0.803 (0.766, 0.836), p = 0.08).

CONCLUSION

CT-based VAT distribution can serve as a potential biomarker for distinguishing IBD subtypes.

CRITICAL RELEVANCE STATEMENT

Visceral fat distribution features extracted from CT images using an automated segmentation algorithm (1.14 min) show differences between Crohn's disease and ulcerative colitis and are promising for practical radiological screening.

KEY POINTS

• Radiological parameters reflecting visceral fat distribution were extracted for the discrimination of Crohn's disease (CD) and ulcerative colitis (UC). • In CD, visceral fat was concentrated in the lower lumbar vertebrae, and the coefficient of variation was a significant predictor (OR = 6.05 (1.17, 31.12), p = 0.03). • The differences between CD, UC, and controls are promising for practical radiological screening.

CT enterography-based radiomics combined with body composition to predict infliximab treatment failure in Crohn's disease

PURPOSE

Accurately predicting the treatment response in patients with Crohn's disease (CD) receiving infliximab therapy is crucial for clinical decision-making. We aimed to construct a prediction model incorporating radiomics and body composition features derived from computed tomography (CT) enterography for identifying individuals at high risk for infliximab treatment failure.

METHODS

This retrospective study included 137 patients with CD between 2015 and 2021, who were divided into a training cohort and a validation cohort with a ratio of 7:3. Patients underwent CT enterography examinations within 1 month before infliximab initiation. Radiomic features of the intestinal segments involved were extracted, and body composition features were measured at the level of the L3 lumbar vertebra. A model that combined radiomics with body composition was constructed. The primary outcome was the occurrence of infliximab treatment failure within 1 year. The model performance was evaluated using discrimination, calibration, and decision curves.

RESULTS

Fifty-two patients (38.0%) showed infliximab treatment failure. Eight significant radiomic features were used to develop the radiomics model. The model incorporating radiomics model score, skeletal muscle index (SMI), and creeping fat showed good discrimination for predicting infliximab treatment failure, with an area under the curve (AUC) of 0.88 (95% CI 0.81, 0.95) in the training cohort and 0.83 (95% CI 0.66, 1.00) in the validation cohort. The favorable clinical application was observed using decision curve analysis.

CONCLUSIONS

We constructed a comprehensive model incorporating radiomics and muscle volume, which could potentially be used to facilitate the individualized prediction of infliximab treatment response in patients with CD.

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.

[Radiologic Diagnosis of Gastrointestinal Bleeding]

Gastrointestinal (GI) bleeding is not a single disease but a symptom and clinical manifestation of a broad spectrum of conditions in the GI tract. According to its clinical presentation, GI bleeding can be classified into overt, occult, and obscure types. Additionally, it can be divided into upper and lower GI bleeding based on the Treitz ligament. Variable disease entities, including vascular lesions, polyps, neoplasms, inflammation such as Crohn's disease, and heterotopic pancreatic or gastric tissue, can cause GI bleeding. CT and conventional angiographies and nuclear scintigraphy are all radiologic imaging modalities that can be used to evaluate overt bleeding. For the work-up of occult GI bleeding, CT enterography (CTE) can be the first imaging modality. For CTE, an adequate bowel distention is critical for obtaining acceptable diagnostic performance as well as minimizing false positives and negatives. Meckel's scintigraphy can be complementarily useful in cases where the diagnosis of CTE is suboptimal. For the evaluation of obscured GI bleeding, various imaging modalities can be used based on clinical status and providers' preferences.

Advances in Imaging of Inflammation, Fibrosis, and Cancer in the Gastrointestinal Tract

Gastrointestinal disease is prevalent and broad, manifesting itself in a variety of ways, including inflammation, fibrosis, infection, and cancer. However, historically, diagnostic technologies have exhibited limitations, especially with regard to diagnostic uncertainty. Despite development of newly emerging technologies such as optoacoustic imaging, many recent advancements have focused on improving upon pre-existing modalities such as ultrasound, computed tomography, magnetic resonance imaging, and endoscopy. These advancements include utilization of machine learning models, biomarkers, new technological applications such as diffusion weighted imaging, and new techniques such as transrectal ultrasound. This review discusses assessment of disease processes using imaging strategies for the detection and monitoring of inflammation, fibrosis, and cancer in the context of gastrointestinal disease. Specifically, we include ulcerative colitis, Crohn's disease, diverticulitis, celiac disease, graft vs. host disease, intestinal fibrosis, colorectal stricture, gastric cancer, and colorectal cancer. We address some of the most recent and promising advancements for improvement of gastrointestinal imaging, including unique discussions of such advancements with regard to imaging of fibrosis and differentiation between similar disease processes.

Imaging Evaluation of Inflammatory Bowel Disease Complications

Inflammatory bowel disease (IBD) is a chronic inflammatory condition that can progress to fibrostenotic and penetrating complications. Cross-sectional imaging is often needed for accurate diagnosis of IBD complication and for planning the appropriate management strategy. Computed tomography enterography, magnetic resonance enterography, and IBD ultrasound have become key tools for clinicians and interventional endoscopists. This article highlights and discusses various radiologic imaging techniques and their application to the diagnosis and management of IBD complications.

Positive Versus Neutral Oral Contrast Material for Detection of Malignant Deposits in Intraabdominal Nonsolid Organs on CT

BACKGROUND. Data are limited regarding utility of positive oral contrast material for peritoneal tumor detection on CT. OBJECTIVE. The purpose of this article is to compare positive versus neutral oral contrast material for detection of malignant deposits in nonsolid intraabdominal organs on CT. METHODS. This retrospective study included 265 patients (133 men, 132 women; median age, 61 years) who underwent an abdominopelvic CT examination in which the report did not suggest presence of malignant deposits and a subsequent CT examination within 6 months in which the report indicated at least one unequivocal malignant deposit. Examinations used positive (iohexol; n = 100) or neutral (water; n = 165) oral agents. A radiologist reviewed images to assess whether the deposits were visible (despite clinical reports indicating no deposits) on unblinded comparison with the follow-up examinations; identified deposits were assigned to one of seven intraabdominal compartments. The radiologist also assessed adequacy of bowel filling with oral contrast material. Two additional radiologists independently reviewed examinations in blinded fashion for malignant deposits. NPV was assessed of clinical CT reports and blinded retrospective readings for detection of malignant deposits visible on unblinded comparison with follow-up examinations. RESULTS. Unblinded review identified malignant deposits in 58.1% (154/265) of examinations. In per-patient analysis of clinical reports, NPV for malignant deposits was higher for examinations with adequate bowel filling with positive oral contrast material (65.8% [25/38]) than for examinations with inadequate bowel filling with positive oral contrast material (45.2% [28/62], p = .07) or with neutral oral contrast material regardless of bowel filling adequacy (35.2% [58/165], p = .002). In per-compartment analysis of blinded interpretations, NPV was higher for examinations with adequate and inadequate bowel filling with positive oral contrast material than for examinations with neutral oral contrast regardless of bowel filling adequacy (reader 1: 94.7% [234/247] and 92.5% [382/413] vs 88.3% [947/1072], both p = .045; reader 2: 93.1% [228/245] and 91.6% [361/394] vs 85.9% [939/1093], both p = .01). CONCLUSION. CT has suboptimal NPV for malignant deposits in intraabdominal nonsolid organs. Compared with neutral material, positive oral contrast material improves detection, particularly with adequate bowel filling. CLINICAL IMPACT. Optimization of bowel preparation for oncologic CT may help avoid potentially severe clinical consequences of missed malignant deposits.

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.

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

BACKGROUND

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).

METHODS

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.

RESULTS

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).

CONCLUSIONS

CTE or MRE imaging findings in combination with HBI can potentially predict which patients will require surgery within 2 years.

A novel food-based foam as oral contrast agent with negative Hounsfield units for demarcation of small bowel loops on abdominal CT: tolerability and bowel distension in 25 volunteers

BACKGROUND

Diseases of the bowel are not always displayed on conventional abdominal computed tomography (CT). The studied oral contrast agent aims to improve this.

PURPOSE

To investigate whether the use of a novel oral contrast for abdominal CT enables the same diagnostic advantages as seen in magnetic resonance imaging (MRI).

MATERIAL AND METHODS

Twenty-five consented volunteers drank up to 1400 mL of a stable, drinkable foam. Comments on acceptance and side effects were noted immediately and 24 h later. Foam palatability was documented through interviews, and distribution in the small bowel by Hounsfield units from the CT software. The CT results were compared with age- and sex-matched controls, pretreated according to routine. A non-enhanced abdominal CT protocol of lowest possible radiation dose was used. External referees evaluated all data obtained.

RESULTS

Foam was considered odd to swallow, and fullness was reported by all volunteers after 950 mL. Five had difficulties in drinking the last 320 mL and two abstained from it. All adverse symptoms were mild. The distribution in the small bowel was on par with standard agents. Foam density revealed stability with intraluminal values of around -550 HU from stomach to terminal ileum, satisfying the requirement of a great bowel lumen-to-wall contrast. External reviewers re-evaluated all our data, and one predicted the foam to offer a potential for improved diagnostics.

CONCLUSION

A CT true-negative bowel filling agent was formulated, with high acceptance, few side effects, and a potential to mimic T1-weighted MRI images.

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.

Shear Wave and Strain Elastography in Crohn's Disease-A Systematic Review

One modern imaging technique used in the diagnosis of Crohn’s disease (CD) is sonoelastrography of the intestine. Guidelines regarding the use of bowel sonoelastography in CD have still not been specified. The aim of our research was to conduct a systematic review of the use of sonoelastography in the diagnosis, assessment, and monitoring of strictures in the course of CD. A systematic review was conducted according to the PRISMA guidelines statement. The following databases were searched in January 2021: MEDINE via PubMed, Embase and Scopus. The search utilised the following MeSH tags: ‘Ultrasound Shear Wave’, ‘Elastography’, ‘elastogram’, ‘elastographies’ AND ‘Crohn disease’. The inclusion criteria were as follows: from 2010 or later, articles with abstracts, articles in English, human-based studies and original articles. Articles were assessed independently by two reviewers. Out of 181 articles, only 15 met the criteria and were included in the review. Due to a small number of studies and significant methodological differences, the feasibility of using sonoelastography for Crohn’s disease must be proven through further research and analysis. In the future, standardised assessment criteria and cut-off points should be established for both strain elastography (SE) and shear wave elastography (SWE).

Cryptogenic multifocal ulcerous stenosing enteritis (CMUSE): a 20-year single-center clinical and radiologic experience

OBJECTIVE

The purpose of this article is to describe clinical and imaging characteristics of confirmed cases of cryptogenic multifocal ulcerous stenosing enteritis (CMUSE).

METHODS

Retrospective review of electronic medical records identified patients considered for a diagnosis CMUSE over 20-years in a single large tertiary center. Clinical data were abstracted and diagnosis was confirmed based on published criteria. Two GI radiologists reviewed CT and MR enterography (CTE/MRE) exams in consensus of confirmed patients to characterize the imaging features of CMUSE.

RESULTS

Eight patients with confirmed CMUSE diagnosis were included for image review, and 9 CTEs and 1 MRE were analyzed. Most patients were males (75%) with a median age at diagnosis of 59.5 years (25-71) presenting with iron deficiency anemia (75%). Patients were commonly refractory (87.5%) to their first therapy, including steroids, with half being refractory to surgical intervention. Major imaging features included multiple (≥ 5; 88%; 7/8), short (< 2 cm; 100%; 8/8), circumferential (100%; 8/8) strictures with moderate wall thickening (6-9 cm), and stratified hyper enhancement (100%; 8/8) located in the ileum (100%; 8/8). Median proximal small bowel dilation was 2.95 cm (2.5-4.1 cm). No CMUSE cases demonstrated penetrating disease (e.g., abscess, fistula).

CONCLUSION

CT and MR enterography are invaluable tools in the multidisciplinary diagnostic evaluation of CMUSE, a rare cause of small bowel strictures with overlapping clinical and imaging features of Crohn's disease and NSAID enteropathy.

Pancreatic Insufficiency in Patients Under Sorafenib Treatment for Hepatocellular Carcinoma

GOALS

To describe the occurrence of malabsorption (MA) in hepatocellular carcinoma (HCC) patients under sorafenib, the potential relationship with pancreatic insufficiency (PI), and the role of pancreatic enzymes supplementation.

BACKGROUND

With the increasing options of second-line systemic therapies for HCC, the recognition of drug intolerance using practical tools is crucial. It has been proposed that a MA syndrome could be due to sorafenib-induced pancreatic dysfunction.

STUDY

All sorafenib-treated patients with suspicion of MA (defined as decreased stool consistency lasting >4 wk or presenting ≥10% body weight loss without HCC progression) were prospectively evaluated by serum markers, endoscopy, and imaging techniques.

RESULTS

We evaluated 81 sorafenib-treated patients and 21 developed MA suspicion (85.7% male, 81.5% Child-Pugh A, 52.4% BCLC-B, and 47.6% BCLC-C) within a median 5.9 months after starting sorafenib. The median treatment duration, follow-up, and overall survival after MA suspicion were 5.9, 20.3, and 20.3 months, respectively. Nine of them (42.9%) presented hyperparathyroidism secondary to vitamin D deficiency and 8 with PI. A gradual decrease in pancreatic volume of up to 19% was observed among patients with PI. Six of the 8 patients with PI received pancreatic enzymes, with complete recovery from MA symptoms and stabilization of pancreatic volume.

CONCLUSIONS

We validated the association between MA and PI in 10% of sorafenib-treated patients. Pancreatic enzymes supplementation successfully led to symptomatic recovery. Awareness of this adverse event can help in the management of sorafenib irrespective of cancer type and likely, of other tyrosine kinase inhibitors for HCC patients.

State of the art in abdominal MRI structured reporting: a review

In the management of several abdominal disorders, magnetic resonance imaging (MRI) has the potential to significantly improve patient's outcome due to its diagnostic accuracy leading to more appropriate treatment choice. However, its clinical value heavily relies on the quality and quantity of diagnostic information that radiologists manage to convey through their reports. To solve issues such as ambiguity and lack of comprehensiveness that can occur with conventional narrative reports, the adoption of structured reporting has been proposed. Using a checklist and standardized lexicon, structured reports are designed to increase clarity while assuring that all key imaging findings related to a specific disorder are included. Unfortunately, structured reports have their limitations too, such as risk of undue report simplification and poor template plasticity. Their adoption is also far from widespread, and probably the ideal balance between radiologist autonomy and report consistency of has yet to be found. In this article, we aimed to provide an overview of structured reporting proposals for abdominal MRI and of works assessing its value in comparison to conventional free-text reporting. While for several abdominal disorders there are structured templates that have been endorsed by scientific societies and their adoption might be beneficial, stronger evidence confirming their imperativeness and added value in terms of clinical practice is needed, especially regarding the improvement of patient outcome.

Crohn's disease at radiological imaging: focus on techniques and intestinal tract

Over recent years, inflammatory bowel diseases have become an issue of increased attention in daily clinical practice, due to both a rising incidence and improved imaging capability in detection. In particular, the diagnosis of Crohn's disease is based on clinical picture, laboratory tests and colonoscopy with biopsy. However, colonoscopic evaluation is limited to the mucosal layer. Thus, imaging modalities play a pivotal role in enriching the clinical picture, delivering information on intestinal and extraintestinal involvement. All the imaging modalities can be employed in evaluation of Crohn's disease patients, each of them with specific strengths as well as limitations. In this wide selection, the choice of a proper diagnostic framework can be challenging for the clinician. Therefore, the aim of this work is to offer an overview of the different imaging techniques, with brief technical details and diagnostic potential related to each intestinal tract.

Anatomic and Functional Imaging of Neuroendocrine Tumors

OPINION STATEMENT

Neuroendocrine tumors (NETs) can occur in a wide variety of organs and display a spectrum of pathologic behavior. Accurate and effective imaging is paramount to the diagnosis, staging, therapy, and surveillance of patients with NET. There have been continuous advancements in the imaging of NET which includes anatomic and functional techniques.

Imaging Findings of Ileal Inflammation at Computed Tomography and Magnetic Resonance Enterography: What do They Mean When Ileoscopy and Biopsy are Negative?

BACKGROUND AND AIMS

Our goal was to determine the importance of ileal inflammation at computed tomography or magnetic resonance enterography in Crohn's disease patients with normal ileoscopy.

METHODS

Patients with negative ileoscopy and biopsy within 30 days of CT or MR enterography showing ileal inflammation were included. The severity [0-3 scale] and length of inflammation within the distal 20 cm of the terminal ileum were assessed on enterography. Subsequent medical records were reviewed for ensuing surgery, ulceration at ileoscopy, histological inflammation, or new or worsening ileal inflammation or stricture on enterography. Imaging findings were classified as: Confirmed Progression [subsequent surgery or radiological worsening, new ulcers at ileoscopy or positive histology]; Radiologic Response [decreased inflammation with medical therapy]; or Unlikely/Unconfirmed Inflammation.

RESULTS

Of 1471 patients undergoing enterography and ileoscopy, 112 [8%] had imaging findings of inflammation with negative ileoscopy, and 88 [6%] had negative ileoscopy and ileal biopsy. Half [50%; 44/88] with negative biopsy had moderate/severe inflammation at enterography, with 45%, 32% and 11% having proximal small bowel inflammation, stricture or fistulas, respectively. Two-thirds with negative biopsy [67%; 59/88] had Confirmed Progression, with 68%, 70% and 61% having subsequent surgical resection, radiological worsening or ulcers at subsequent ileoscopy, respectively. Mean length and severity of ileal inflammation in these patients was 10 cm and 1.6. Thirteen [15%] patients had Radiologic Response, and 16 [18%] had Unlikely/Unconfirmed Inflammation.

CONCLUSION

Crohn's disease patients with unequivocal imaging findings of ileal inflammation at enterography despite negative ileoscopy and biopsy are likely to have active inflammatory Crohn's disease. Disease detected by imaging may worsen over time or respond to medical therapy.

Computed tomography and magnetic resonance enterography protocols and techniques: survey of the Society of Abdominal Radiology Crohn's Disease Disease-Focused Panel

PURPOSE

To survey Society of Abdominal Radiology Crohn's Disease (CD) Disease-Focused Panel (DFP) members to understand state-of-the-art CT/MR enterography (CTE/MRE) protocols and variability between institutions.

METHODS

This study was determined by an institutional review board to be "exempt" research. The survey consisted of 70 questions about CTE/MRE patient preparation, administration of contrast materials, imaging techniques, and other protocol details. The survey was administered to DFP members using SurveyMonkey® (Surveymonkey.com). Descriptive statistical analyses were performed.

RESULTS

Responses were received from 16 DFP institutions (3 non-USA, 2 pediatric); 15 (94%) were academic/university-based. 10 (63%) Institutions image most CD patients with MRE; 4 (25%) use CTE and MRE equally. Hypoperistaltic medication is given for MRE at 13 (81%) institutions versus only 2 (13%) institutions for CTE. Most institutions have a technologist or nurse monitor oral contrast material drinking (n = 12 for CTE, 75%; n = 11 for MRE, 69%). 2 (13%) institutions use only dual-energy capable scanners for CTE, while 9 (56%) use either a single-energy or dual-energy scanner based on availability. Axial CTE images are reconstructed at 2-3 mm thickness at 8 (50%) institutions, > 3 mm at 5 (31%), and < 2 mm at 3 (19%) institutions. 13 (81%) institutions perform MRE on either 1.5 or 3T scanners without preference. All institutions perform MRE multiphase postcontrast imaging (median = 4 phases), ranging from 20 to 600 s after contrast material injection.

CONCLUSION

CTE and MRE protocol knowledge from DFP institutions can help radiology practices optimize/standardize protocols, potentially improving image quality and patient outcomes, permitting objective comparisons between examinations, and facilitating research.

[Preparation, Technique, and Imaging of Computed Tomography/Magnetic Resonance Enterography]

CT enterography and magnetic resonance (MR) enterography are widely used imaging modalities used to examine the small bowel. These radiologic tests are distinguished from routine abdominopelvic CT and MRI by the oral ingestion of a large amount of neutral contrast to distend the small bowel before scanning. For achievement of high quality, diagnostic images and proper technique are required. Conducted protocols still vary in patient preparation, enteric contrast, and CT and MRI acquisition sequences, resulting in heterogeneous diagnostic accuracy. The purpose of this article is to review the processes and techniques that optimize CT/MR enterography for patients with suspected Crohn's disease or other small bowel diseases.

Development of an Objective Model to Define Near-Term Risk of Ileocecal Resection in Patients with Terminal Ileal Crohn Disease

BACKGROUND

The decision to either escalate medical therapy or proceed to ileocecal resection (ICR) in patients with terminal ileal Crohn disease (CD) remains largely subjective. We sought to develop a risk score for predicting ICR at 1 year from computed tomography or magnetic resonance enterography (CTE/MRE).

METHODS

We conducted a retrospective cohort study including all consecutive adult (> 18 years) patients with imaging findings of terminal ileal CD (Montreal classification: B1, inflammatory predominant; B2, stricturing; or B3, penetrating) on CTE/MRE between January 1, 2016, and December 31, 2016. The risk for ICR at 6 months and at 1 year of CTE/MRE and risk factors associated with ICR, including demographics, CD-specific immunosuppressive therapeutics, and disease presentation at the time of imaging, were determined.

RESULTS

Of 559 patients, 121 (21.6%) underwent ICR during follow-up (1.4 years [IQR 0.21-1.64 years]); the risk for ICR at 6 months and at 1 year was 18.2% (95% CI 14.7%-21.6%) and 20.5% (95% CI 16.8%-24.1%), respectively. Multivariable analysis revealed Montreal classification (B2, hazard ratio [HR] 2.73, and B3, HR 6.80, both P < 0.0001), upstream bowel dilation (HR 3.06, P < 0.0001), and younger age (19-29 years reference, 30-44 years, HR 0.83 [P = 0.40]; 45-59 years, HR 0.58 [P = 0.04], and 60+ years, HR 0.45 [P = 0.01]) to significantly increase the likelihood of ICR. A predictive nomogram for interval ICR was developed based on these significant variables.

CONCLUSIONS

The presence of CD strictures, penetrating complications, and upstream bowel dilation on CTE/MRE, combined with young age, significantly predict ICR. The suggested risk model may facilitate objective therapeutic decision-making.

Comparison of two small bowel distending agents for enterography in pediatric small bowel imaging

OBJECTIVE

To evaluate the ability of pediatric patients with known or suspected inflammatory bowel disease to ingest a new oral distending agent at CT or MR enterography (CTE/MRE), and to determine the impact on small bowel (SB) distension and diagnostic confidence.

MATERIALS AND METHODS

The study design is that of retrospective review of pediatric patients who underwent CTE or MRE from January 2014 to June 2016. Patients ingested low-concentration barium suspension or flavored beverage containing sorbitol and mannitol. The need for nasogastric tube (NGT) administration, amount ingested, emesis, distal extent of contrast, SB distension, terminal ileum (TI) transverse dimension, and diagnostic confidence in TI disease were assessed. Three radiologists each blindly reviewed a subset of the studies.

RESULTS

Of the total 591 scans in 504 patients, 316 scans used low-concentration barium suspension and 275 scans flavored beverage. Nearly all consumed the entire amount (97% vs. 96%). Low-concentration barium suspension exams required NGT more often (7% [23/316] vs. 1% [3/275]; p < 0.0003), and tended to have more emesis (3% [9/316] vs. 1% [3/275]; p = 0.13). Diagnostic confidence score was nearly identical (p = 0.94). Qualitative and quantitative analyses showed no difference in SB distension, except for distension of mid-ileum (flavored beverage > low-concentration barium suspension; p = 0.02). Flavored beverage exams demonstrated a slight increase in distal extent of luminal distension (p = 0.02).

CONCLUSIONS

A new flavored beverage distends small bowel as well as low-concentration barium suspension, with decreased requirement for NGT insertion and improved distal extent of luminal distension, and without any decrease in diagnostic confidence in the presence or the absence of TI disease.

The Role of the Radiologist in Determining Disease Severity in Inflammatory Bowel Diseases

Crohn's disease and ulcerative colitis are chronic inflammatory diseases that lead to progressive bowel damage including the development of stricturing and penetrating complications. Increasingly, cross-sectional imaging with computed tomography or magnetic resonance scans have emerged as leading tools to: (1) assess disease activity; (2) monitor response to therapy or disease recurrence; and (3) identify disease-related complications. Several validated radiological scoring systems have been developed to quantify cross-sectional and longitudinal inflammatory burden in these diseases and to monitor response to treatment. Bowel ultrasound is also a simple and inexpensive tool but is operator dependent in its performance.

Differences in the imaging of Crohn's disease patients between North America and Europe: are we ready to bridge the divide?

The emphasis of treatment in Crohn's disease has evolved from a reactive model to "treat-to-target" approaches. Cross-sectional imaging has rapidly evolved in parallel, with a growing evidence base supporting its abilities for diagnosis, monitoring and prognostication. Whilst there are differences in emphasis between Europe and North America, particularly around the type of imaging modalities and patterns of multidisciplinary care, there is increasing convergence. This perspective piece provides an overview of the evolving role of cross-sectional imaging in Crohn's disease, discusses practice differences between North America and Europe and provides suggestions on areas for future collaboration and research priorities.

The Clinician's Guide to Suspected Small Bowel Bleeding

Small bowel bleeding accounts for 5-10% of gastrointestinal bleeding. With the advent of capsule endoscopy, device-assisted enteroscopy, and multiphase CT scanning, a small bowel source can now be found in many instances of what has previously been described as obscure gastrointestinal bleeding. We present a practical review on the evaluation and management of small bowel bleeding for the practicing clinician.

A closer look at the stoma: multimodal imaging of patients with ileostomies and colostomies

Nowadays, large numbers of ileostomies and colostomies are created during surgical management of a variety of intestinal disorders. Depending on indication, surgical technique and emergency versus elective conditions, stomas may be either temporary or permanent. As a result, patients with ileostomies and colostomies are commonly encountered in Radiology departments, particularly during perioperative hospitalisation following stoma creation or before recanalisation, and when needing CT or MRI studies for follow-up of operated tumours or chronic inflammatory bowel diseases. However, the stoma site is commonly overlooked on cross-sectional imaging.Aiming to improve radiologists' familiarity with stoma-related issues, this pictorial essay concisely reviews indications and surgical techniques for ileostomies and colostomies, and presents state-of-the art multimodal imaging in patients living with a stoma, including water-soluble contrast stomal enema (WSC-SE), CT and MRI techniques, interpretation and expected findings. Afterwards, the clinical features and imaging appearances of early and late stoma-related complications are illustrated with imaging examples, including diversion colitis.When interpreting cross-sectional imaging studies, focused attention to the stoma site and awareness of expected appearances and of possible complications are required to avoid missing significant changes requiring clinical attention. Additionally, dedicated imaging techniques such as WSC-SE and combined CT plus WSC-SE may be helpful to provide surgeons the appropriate clinical information required to direct management.

Novel Imaging Approaches in Inflammatory Bowel Diseases

Inflammatory bowel diseases are chronic autoimmune conditions of the gastrointestinal tract, mainly grouped into ulcerative colitis or Crohn's disease. Traditionally, symptoms have been used to guide IBD management, but this approach is fatally flawed, as symptoms don't correlate with disease activity and often fail to predict disease complications, especially with Crohn's disease. Hence, there is increasing recognition of the need for treatment algorithms based on objective measures of bowel inflammation. In this review, we will focus on advancements in the endoscopic and radiological imaging armamentarium that allow detailed assessments from intestinal mucosa to mesentery.

How We Do It: Creating Consistent Structure and Content in Abdominal Radiology Report Templates

OBJECTIVE

The purposes of this article are to describe the creation of template report formats and content for a variety of abdominal and pelvic CT and MRI examinations and discuss a review-of-systems approach to text and avoidance of pitfalls of report templates.

CONCLUSION

Organ system-specific report templates for CT and MRI incorporate radiologist preferences. Disease-specific report templates are created from these reports to provide a consistent radiologist and referring physician experience across the report templates.

Radiologic Assessment of Gastrointestinal Bleeding

Gastrointestinal (GI) bleeding represents a broad differential of disease throughout the GI tract. The proper diagnostic evaluation of patients presenting with symptoms of GI bleeding depends on the overall clinical acuity and suspected source locations. The radiologic assessment of these patients is centered around computed tomography (CT) angiography, CT enterography, conventional angiography, and nuclear scintigraphy.

Computed Tomography and Magnetic Resonance Small Bowel Enterography: Current Status and Future Trends Focusing on Crohn's Disease

Computed tomography enterography (CTE) and magnetic resonance enterography (MRE) are presently state-of-the-art radiologic tests used to examine the small bowel for various indications. This article focuses on CTE and MRE for the evaluation of Crohn disease. The article describes recent efforts to achieve more standardized interpretation of CTE and MRE, summarizes recent research studies investigating the role and impact of CTE and MRE more directly for several different clinical and research issues beyond general diagnostic accuracy, and provides an update on progress in imaging techniques. Also addressed are areas that need further exploration in the future.

Imaging Workup of Acute and Occult Lower Gastrointestinal Bleeding

Lower gastrointestinal bleeding is defined as occurring distal to the ligament of Treitz and presents as hematochezia, melena, or with anemia and positive fecal occult blood test. Imaging plays a pivotal role in the localization and treatment of lower gastrointestinal bleeds. Imaging tests in the workup of acute lower gastrointestinal bleeding include computed tomography (CT) angiography, nuclear medicine scintigraphy, and conventional catheter angiography. Catheter angiography can also be used to deliver treatment. Imaging tests in the workup of occult lower gastrointestinal bleeding include CT enterography and nuclear medicine Meckel scan.

Computed Tomography Enterography

Computed tomography (CT) enterography is a noninvasive imaging modality with superb spatial and temporal resolution, specifically tailored to evaluate the small bowel. It has several advantages over other radiologic and optical imaging modalities, all of which serve as complementary investigations to one another. This article describes CTE technique, including dose reduction techniques, special considerations for the pediatric population, common technical and interpretive pitfalls, and reviews some of the more common small bowel entities seen with CTE.

Magnetic Resonance Enterography for Inflammatory and Noninflammatory Conditions of the Small Bowel

Magnetic resonance enterography (MRE) is an effective noninvasive tool for evaluation of inflammatory and noninflammatory conditions of the small bowel. MRE allows for repeated evaluation of patients with Crohn disease without exposure to ionizing radiation, and can be used to assess disease status and direct management. MRE also allows evaluation of neoplastic and other nonneoplastic conditions of the small bowel. Adequate patient preparation and acquisition techniques are required for optimal image quality.

Small bowel imaging in Crohn's disease patients

Crohn’s disease (CD) is a lifelong, chronic inflammatory bowel disorder. The small bowel (SB) is involved to varying extents, and the clinical course may vary from an inflammatory type to a more complicated one with stricture, fistula, and abscess formation. Esophagogastroduodenoscopy and ileocolonoscopy with biopsies are the conventional endoscopic techniques that usually establish the diagnosis. On the other hand, CD may affect SB segments that cannot be reached through these procedures. Video capsule endoscopy and enteroscopy are additional endoscopic techniques that may allow further SB evaluation in such circumstances. Computed tomographic enterography, magnetic resonance enterography, and ultrasonography are radiologic techniques that serve as a crucial adjunct to endoscopic assessment. They enable the assessment of parts of the bowel that may be difficult to reach with conventional endoscopy; this allows for the detection of active inflammation, penetrating or stricturing disease, and the appreciation of extraintestinal complications. Both endoscopic and radiologic modalities play a role in establishing the diagnosis of CD, as well as determining the disease extent, activity and response to therapy. This review is intended to evaluate these modalities in terms of specificity, sensitivity, potential side-effects, and limiting factors. This should serve as a guide to the clinician for establishing the most appropriate and reliable test within a particular clinical context.

The accuracy of intestinal ultrasound compared with small bowel capsule endoscopy in assessment of suspected Crohn's disease in patients with negative ileocolonoscopy

BACKGROUND

Small bowel involvement in Crohn's disease (CD) is frequently proximal to the ileocecal valve and inaccessible by conventional ileocolonoscopy (IC). Small bowel capsule endoscopy (SBCE) is among the prime modalities for assessment of small bowel disease in these patients. Intestinal ultrasound (IUS) is an accurate bedside fast and low-cost diagnostic modality utilized in CD for both diagnosis and monitoring. The aim of this study was to examine the accuracy of IUS in patients with suspected CD after a negative IC, and to evaluate the correlation of IUS with SBCE, inflammatory biomarkers and other cross-sectional imaging techniques.

METHODS

Prospective single center study in which patients with suspected CD underwent IUS and SBCE examinations within 3 days. IUS results were blindly compared with SBCE that served as the gold standard. A post hoc comparison was performed of IUS and SBCE results and available cross-sectional imaging results (computed tomography or magnetic resonance enterography) as well as inflammatory biomarkers if measured. The study cohort was followed for 1 year. In case of discordance between the IUS and SBCE results, the diagnosis at 1 year was reported.

RESULTS

Fifty patients were included in the study. The diagnostic yield of both IUS and SBCE for the diagnosis of small bowel CD was 38%. The IUS findings significantly correlated to small bowel inflammation detected by SBCE (r = 0.532, p < 0.001), with fair sensitivity and specificity (72% and 84%). Cross-sectional imaging results significantly correlated to IUS as well (r = 0.46, p = 0.018). Follow up was available in 8 of the 10 cases of discordance between IUS and SBCE. In all of these cases, diagnosis of CD was not fully established at the end of the follow up.

CONCLUSIONS

The diagnostic yield of CE and IUS for detection of CD in patients with negative ileocolonoscopy was similar. IUS can be a useful diagnostic tool in suspected CD when IC is negative.

Consensus Recommendations for Evaluation, Interpretation, and Utilization of Computed Tomography and Magnetic Resonance Enterography in Patients With Small Bowel Crohn's Disease

Computed tomography and magnetic resonance enterography have become routine small bowel imaging tests to evaluate patients with established or suspected Crohn's disease, but the interpretation and use of these imaging modalities can vary widely. A shared understanding of imaging findings, nomenclature, and utilization will improve the utility of these imaging techniques to guide treatment options, as well as assess for treatment response and complications. Representatives from the Society of Abdominal Radiology Crohn's Disease-Focused Panel, the Society of Pediatric Radiology, the American Gastroenterological Association, and other experts, systematically evaluated evidence for imaging findings associated with small bowel Crohn's disease enteric inflammation and established recommendations for the evaluation, interpretation, and use of computed tomography and magnetic resonance enterography in small bowel Crohn's disease. This work makes recommendations for imaging findings that indicate small bowel Crohn's disease, how inflammatory small bowel Crohn's disease and its complications should be described, elucidates potential extra-enteric findings that may be seen at imaging, and recommends that cross-sectional enterography should be performed at diagnosis of Crohn's disease and considered for small bowel Crohn's disease monitoring paradigms. A useful morphologic construct describing how imaging findings evolve with disease progression and response is described, and standard impressions for radiologic reports that convey meaningful information to gastroenterologists and surgeons are presented.

Consensus Recommendations for Evaluation, Interpretation, and Utilization of Computed Tomography and Magnetic Resonance Enterography in Patients With Small Bowel Crohn's Disease

Computed tomography and magnetic resonance enterography have become routine small bowel imaging tests to evaluate patients with established or suspected Crohn's disease, but the interpretation and use of these imaging modalities can vary widely. A shared understanding of imaging findings, nomenclature, and utilization will improve the utility of these imaging techniques to guide treatment options, as well as assess for treatment response and complications. Representatives from the Society of Abdominal Radiology Crohn's Disease-Focused Panel, the Society of Pediatric Radiology, the American Gastroenterological Association, and other experts, systematically evaluated evidence for imaging findings associated with small bowel Crohn's disease enteric inflammation and established recommendations for the evaluation, interpretation, and use of computed tomography and magnetic resonance enterography in small bowel Crohn's disease. This work makes recommendations for imaging findings that indicate small bowel Crohn's disease, how inflammatory small bowel Crohn's disease and its complications should be described, elucidates potential extra-enteric findings that may be seen at imaging, and recommends that cross-sectional enterography should be performed at diagnosis of Crohn's disease and considered for small bowel Crohn's disease monitoring paradigms. A useful morphologic construct describing how imaging findings evolve with disease progression and response is described, and standard impressions for radiologic reports that convey meaningful information to gastroenterologists and surgeons are presented. ^©2018, RSNA, AGA Institute, and Society of Abdominal Radiology This article is being published jointly in Radiology and Gastroenterology.