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

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.

Comparison of an Endoscopic Scoring System and the Simplified Magnetic Resonance Index of Activity in Patients with Small Bowel Crohn's Disease

Background/Aims

The newly derived simplified magnetic resonance index of activity (MARIAs) has not been verified in comparison to balloon-assisted enteroscopy (BAE) for patients with small bowel Crohn's disease (CD). We studied the correlation of MARIAs with simple endoscopic scores for CD (SES-CD) of the ileum based on magnetic resonance enterography (MRE) and BAE in patients with small bowel CD.

Methods

Fifty patients with small bowel CD who underwent BAE and MRE concurrently within 3 months from September 2020 to June 2021 were enrolled in the study. The primary outcome was the correlation between the active score of ileal SES-CD (ileal SES-CDa)/ileal SES-CD and MARIAs based on BAE and MRE. The cutoff value for MARIAs identifying endoscopically active/severe disease, defined as ileal SES-CDa/ileal SES-CD of 5/7 or more, was analyzed.

Results

Ileal SES-CDa/ileal SES-CD and MARIAs showed strong associations (R=0.76, p<0.001; R=0.78, p<0.001). The area under the receiver operating characteristic curve of MARIAs for ileal SES-CDa ≥5 and ileal SES-CD ≥7 was 0.92 (95% confidence interval, 0.88 to 0.97) and 0.92 (95% confidence interval, 0.87 to 0.97). The cutoff value of MARIAs for detecting active/severe disease was 3. A MARIAs index value of ≥3 identified ileal SES-CDa ≥5 with a sensitivity of 85% and specificity of 87% and detected ileal SES-CD ≥7 with a sensitivity of 87% and specificity of 86%.

Conclusions

This study validated the applicability of MARIAs compared to BAE-based ileal SES-CDa/SES-CD.

Crohn's disease and clinical management today: How it does?

Crohn's Disease (CD) is an Inflammatory Bowel Disease and is characterized by an immune-mediated nature. Its etiology results from the interaction between genetic, enviromental and microbial factors. Regarding pathophysiology, it involves high levels of interleukin (IL)-12, IL-17, and Th1 profile, along with loss of tolerance mechanisms, an increase in pro-inflammatory interleukins, beyond the possibility to affect any part of the gastrointestinal tract. Its symptoms include abdominal pain, chronic diarrhea, weight loss, anorexia, and fatigue, as well as blood in the stool or rectum. Additionally, conditions comprising musculoskeletal, cutaneous, ocular, hepatic, and hematological alterations may be associated with this scenario and extra-intestinal presentation, such as erythema nodosum, anterior uveitis, osteoporosis, and arthritis can also occur. Today, clinical history, exams as fecal calprotectin, ileocolonocopy, and capsule endoscopy can be performed in the diagnosis investigation, along with treatments to induce and maintain remission. In this sense, anti-inflammatory drugs, such as corticosteroids, immunomodulators, and biological agents, as well as surgery and non-pharmacological interventions plays a role in its therapy. The aim of this review is to bring more current evidence to clinical management of CD, as well as to briefly discuss aspects of its pathophysiology, surveillance, and associated disorders.

Reclassification of Inflammatory Bowel Disease Type Unclassified by Small Bowel Capsule Endoscopy

Background and Objectives: Ulcerative colitis (UC) and Crohn's disease (CD) are idiopathic inflammatory bowel diseases (IBDs) without a unique, gold standard diagnostic test. UC and Crohn's colitis are impossible to distinguish in approximately 10% of cases. The term IBD type unclassified (IBD-U) is recommended for cases of chronic colitis showing overlapping endoscopic, radiological, and biopsy histological features between UC and CD, while indetermined colitis is reserved for colectomy specimens. Our aim was to assess the role of small-bowel capsule endoscopy (SBCE) in the diagnostic work-up of IBD-U. Materials and Methods: We retrospectively studied the cases of IBD-U explored by SBCE in a tertiary referral gastroenterology center. Patients were investigated using SBCE after contraindications were excluded. Diagnostic criteria for small bowel CD consisted in more than three ulcerations, irregular ulcers, or stenosis, and the Lewis score was used for the quantification of inflammation. The immediate impact of reclassification and outcome data was recorded over a follow-up period of more than one year. Results: Twenty-eight patients with IBD-U were examined using SBCE. Nine patients had small bowel lesions that met the diagnostic criteria for CD, resulting in a reclassification rate of 32.1%. In five of these cases, the treatment was subsequently changed. In the remaining nineteen examinations, no significant findings were observed. There were no complications associated with SBCE. Median follow-up time was 32.5 months (range 12-60). During follow-up, twelve patients were classified as having UC, and seven remained as having an unclassified type; one case of colectomy, for medically refractory UC, was recorded. Conclusions: SBCE is a useful safe tool in the work-up of IBD-U, allowing reclassification in about one third of cases, with subsequent treatment modifications. SBCE may provide a definite diagnosis, enhance the comprehension of the disease's progression, and optimize the short- and long-term management strategy.

Colonic involvement in inflammatory bowel diseases: spotlight on the role of magnetic resonance enterography

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

Distribution of small bowel involvement and its association with clinical outcomes in patients with Crohn's disease

We aimed to evaluate the distribution of small-bowel involvement in Crohn's disease (CD) and its association with clinical outcomes. This study included CD patients who underwent computed tomography (CT) at initial diagnosis from June 2006 to April 2021. Two abdominal radiologists reviewed the CT images, and independently rated the presence of "bowel wall thickening," "stricture," and "fistula or abscess" in the small bowel segments of jejunum, distal jejunum/proximal ileum, distal ileum, and terminal ileum, respectively. Based on findings of the image review, each patient's "disease-extent imaging score" and "behavior-weighted imaging score" (a higher score indicative of more structuring or penetrating disease) were calculated. Major clinical outcomes (emergency department [ED] visit, operation, and use of corticosteroids or biologics) were compared according to the 2 scores and L4 involvement by the Montreal classification. The proportions of involvement in the jejunum, distal jejunum/proximal ileum, distal ileum, and terminal ileum were 2.0%, 30.3%, 82.2%, and 71.7%, respectively, identifying 30.3% of patients as having L4 disease and 69.7% of patients as having involvement of multiple segments. Clinical outcomes were not significantly associated with the disease-extent imaging score or L4 involvement. However, significant differences were noted for the ED visits and the use of biologics, according to the behavior-weighted imaging score. Moreover, in multivariable analysis, disease behavior was the only factor associated with all clinical outcomes (ED visit, hazard ratio [HR] 2.127 [1.356-3.337], P = .001; operation, HR 8.216 [2.629-25.683], P < .001; use of corticosteroid, HR 1.816 [1.249-2.642], P = .002; and use of biologics, HR 2.352 [1.492-3.708], P < .001). Initial disease behavior seems to be a more critical factor for clinical outcomes of CD than the extent or distribution of small-bowel involvement on CT.

DWI ratios: New indexes for Crohn's disease activity at magnetic resonance enterography?

BACKGROUND

The aim of the study was to provide radiologists and clinicians a rapid tool for assessment of intestinal inflammation in Crohn's disease (CD) patients through quantification of diffusion-weighted imaging (DWI) signal intensity while performing magnetic resonance enterography (MRE).

MATERIALS AND METHODS

A monocentric retrospective study was conducted between September 2018 and July 2021 on CD patients who underwent MRE. Two radiologists measured signal intensity on DWI scans at the highest b-value (800 s/mm²) within pathologic intestinal walls, lymph nodes, spleen and psoas muscle and calculated the relative ratios. Spearman, Mann-Whitney and Jonckheere-Terpstra tests were applied for estimating correlation among ratios, significant differences between the two patient groups and determining the trend in relation to endoscopic classes. Wilcoxon's and Cronbach's alpha tests were employed for comparison of DWI measurements and ratios between the two observers.

RESULTS

Fifty-nine patients were enrolled in the study. In the non-surgical group, correlation has been found among Simple Endoscopic Score for Crohn's Disease (SES-CD) classes and the different ratios: bowel/spleen (p = 0.034), bowel/psoas (p = 0.008) and bowel/lymph node (p = 0.010). Within the surgical group, positive correlation was found only between bowel/lymph node ratio and bowel/psoas ratio (p = 0.014). The J-T test demonstrated an increasing monotonic trend for bowel/psoas ratio and bowel/lymph node ratio and SES-CD classes. Inter-reader evaluation demonstrated no statistical differences for DWI measurements and high degree of concordance for the final ratios.

CONCLUSION

DWI ratios correlate with endoscopic classes in non-surgical patients and have inter-observer reproducibility.

Unique coexistence of chronic midgut malrotation, mesenteric cyst, and pancreas divisum in a Crohn's disease patient: MR-enterography assessment

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

Portal hypertensive enteropathy: multimodality assessment through computed tomography and magnetic resonance enterography

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

Endoscopic activity in inflammatory bowel disease: clinical significance and application in practice

Endoscopy is vital for diagnosing, assessing treatment response, and monitoring surveillance in patients with inflammatory bowel disease (IBD). With the growing importance of mucosal healing as a treatment target, the assessment of disease activity by endoscopy has been accepted as the standard of care for IBD. There are many endoscopic activity indices for facilitating standardized reporting of the gastrointestinal mucosal appearance in IBD, and each index has its strengths and weaknesses. Although most endoscopic indices do not have a clear-cut validated definition, endoscopic remission or mucosal healing is associated with favorable outcomes, such as a decreased risk of relapse. Therefore, experts suggest utilizing endoscopic indices for monitoring disease activity and optimizing treatment to achieve remission. However, the regular monitoring of endoscopic activity is limited in practice owing to several factors, such as the complexity of the procedure, time consumption, inter-observer variability, and lack of a clear-cut, validated definition of endoscopic response or remission. Although experts have recently suggested consensus-based definitions, further studies are needed to define the values that can predict long-term outcomes.

Microbial changes in stool, saliva, serum, and urine before and after anti-TNF-α therapy in patients with inflammatory bowel diseases

Inflammatory bowel diseases (IBD), including Crohn's disease and ulcerative colitis, are chronic immune-mediated intestinal inflammatory disorders associated with microbial dysbiosis at multiple sites, particularly the gut. Anti-tumor necrosis factor-α (TNF-α) agents are important treatments for IBD. We investigated whether microbiome changes at multiple sites can predict the effectiveness of such treatment in IBD. Stool, saliva, serum, and urine biosamples were collected from 19 IBD patients before (V1) and 3 months after (V2) anti-TNF-α treatment, and 19 healthy subjects (control). Microbiota analysis was performed using extracellular vesicles (EVs; all four sample types) and next-generation sequencing (NGS; stool and saliva). The stool, using NGS analysis, was the only sample type in which α-diversity differed significantly between the IBD and control groups at V1 and V2. Relative to non-responders, responders to anti-TNF-α treatment had significantly higher levels of Firmicutes (phylum), Clostridia (class), and Ruminococcaceae (family) in V1 stool, and Prevotella in V1 saliva. Non-responders had significantly higher V2 serum and urine levels of Lachnospiraceae than responders. Finally, Acidovorax caeni was detected in all V1 sample types in responders, but was not detected in non-responders. Microbiome changes at multiple sites may predict the effectiveness of anti-TNF-α treatment in IBD, warranting further research.

Overview of the Large Bowel Assessment Using Magnetic Resonance Imaging: Different Techniques for Current and Emerging Clinical Applications

Radiological assessments of the small and large bowel are essential in daily clinical practice. Over plain film X-ray and ultrasound, cross-sectional techniques are considered the most comprehensive imaging modalities. In fact, computed tomography and magnetic resonance imaging take great advantage of the three-dimensional appraisal and the extensive evaluation of the abdominal cavity, allowing intestinal evaluation as well as detection of extra-intestinal findings. In this context, the chief advantage of computed tomography is the fast scan time, which is crucial for emergency cases. Nonetheless, it is undeniably impaired using ionizing radiation. As the awareness of radiation exposure is a topic of increasing importance, magnetic resonance imaging is not only becoming a mere alternative but also a primary imaging technique used in assessing intestinal diseases. Specifically, the evaluation of the large bowel through MRI can be still considered relatively uncharted territory. Although it has demonstrated superior accuracy in the assessment of some clinical entities from inflammatory bowel disease to rectal carcinoma, its role needs to be consolidated in many other conditions. Moreover, different technical methods can be applied for colonic evaluation depending on the specific disease and segment involved. This article aims to provide a thorough overview of the techniques that can be utilized in the evaluation of the large bowel and a discussion on the major findings in different colonic pathologies of primary interest.

Magnetic resonance enterography in Crohn's disease patients: current state of the art and future perspectives

INTRODUCTION

Crohn's disease (CD) is a major concern due to relatively high incidence and major complications like stricture or fistulas, often requiring surgical treatment. In recent years, magnetic resonance enterography (MRE) became a popular method of diagnosis and disease surveillance. The purpose of this review is to summarize and discuss the major and most recent advances in various aspects of MRE usage in diagnosong Crohn's disease, and to discuss advances in technique, disease activity monitoring and response to treatment.

METHODS

A literature search was performed and relevant publications were included, with emphasis on articles from the past decade.

AREAS COVERED

In this review we have presented articles with major advances in the field of MRE of CD patients such as proper sequence selection, recent advances in scoring of disease activity, differentiation between inflammation and fibrosis, response to treatment and technological advances such as the use of AI.

EXPERT OPINION

The main goal in improving MRE performance will be sequence selection aimed at differenting between inflammation and stricture while shortening the study length adjusted to patient compliance, and developing a standardized scoring system for MRE reporting assisted by artificial intelligence.

Mimicking conditions of intestinal Crohn's disease: magnetic resonance enterography findings

Crohn's disease is a chronic inflammatory condition characterized by a transmural involvement of intestinal walls. Its diagnosis comes from a combination of clinical data, imaging findings and, above all, endoscopy with biopsy results, which are mandatory for achieving a definitive diagnosis. Even so, endoscopy information may be unavailable, for instance due to technical impairments or patient intolerance. On the radiological side, Magnetic Resonance Enterography is currently considered the imaging technique of choice for Crohn's disease assessment, either at first diagnosis or follow-up. Nevertheless, the lack of radiation exposure as well as invasiveness has made this imaging approach suitable also for the evaluation of a number of small and large bowel diseases over recent years. However, it is important to remember that Magnetic Resonance Imaging findings are non-specific and that a wide overlap exists among Crohn's disease and other intestinal conditions. The aim of this work was to provide a series of intestinal affections evaluated through Magnetic Resonance Enterography that resemble Crohn's disease and that can be helpful in avoiding misinterpretation, especially when endoscopy data are missing.

Elective surgery outcomes in inflammatory bowel disease: interpretation at magnetic resonance enterography

Inflammatory bowel diseases include pathologic intestinal conditions of unknown etiology, such as Crohn's disease and ulcerative colitis. Crohn's disease consists in a chronic transmural inflammation that can affect any part of the gastrointestinal tract and whose clinical course is characterized by a fluctuation of remission and recurrences, while inflammation in ulcerative colitis involves the solely layer of colonic mucosa. Cross-sectional imaging, and especially magnetic resonance enterography, is able to provide useful information about small bowel lesions as well as intestinal and extra-intestinal complications.However, morphological changes due to surgery can significantly impair the evaluation of small and large bowel, especially considering that the majority of CD patients undergo one or more surgical operations during their lifetime. Therefore, the aim of this work is to summarize the main surgical approaches in inflammatory bowel disease patients and the consequent findings on magnetic resonance enterography.