Grading of Crohn's disease activity using CT, MRI, US and scintigraphy: a meta-analysis

Assessment of activity and severity of inflammatory bowel disease in cross-sectional imaging techniques: a systematic review

BACKGROUND AND AIMS

Cross-sectional imaging techniques, including intestinal ultrasonography (IUS), computed tomography enterography (CTE), magnetic resonance enterography (MRE), are increasingly used for the evaluation of inflammatory bowel diseases (IBD). We aimed to systematically review literature evidence on the assessment of disease activity, and/or severity through cross-sectional imaging in IBD patients, and to offer guidance on their most effective utilization.

METHODS

We performed a systematic review of PubMed, EMBASE, and Scopus to identify citations pertaining to the assessment of disease activity and/or severity at cross-sectional imaging techniques compared to a reference standard (ie, other radiological techniques, endoscopy, histopathology, and surgery) in IBD patients published until December 2023.

RESULTS

Overall, 179 papers published between 1990 and 2023 were included, with a total of 10 988 IBD patients (9304 Crohn's disease [84.7%], 1206 ulcerative colitis [11.0%], 38 IBD-U [0.3%], 440 unspecified [4.0%]). Of the 179 studies, 39 investigated IUS, 22/179 CTE, and 101/179 MRE. In the remaining papers, 2 techniques were addressed together. In 81.6% of the papers, endoscopy (with or without histopathology) was used as a reference standard. All studies included evaluated disease activity, while just over half (100/179, 55.8%) also evaluated disease severity of the addressed cross-sectional methodology. Pooled sensitivity, specificity, and overall accuracy of IUS, MRE, and CTE compared to the reference standard were 60%-99%, 60%-100%, and 70%-99%, respectively.

CONCLUSIONS

All cross-sectional imaging techniques demonstrated moderate-to-good accuracy in assessing disease activity and severity of IBD. This finding highlights the potential, especially for MRE and IUS to be widely utilized in managing IBD in both clinical practice and clinical trials.

Application Value of Endoscopic Ultrasonography in Diagnosis and Treatment of Inflammatory Bowel Disease

Inflammatory bowel disease refers to a group of non-specific inflammatory illnesses affecting the gastrointestinal tract. According to pathogenic characteristics, it is divided into Ulcerative colitis and Crohn's disease. The exact cause and pathogenic mechanism of these disorders are not yet fully understood. In addition, there is currently no definitive diagnostic method for inflammatory bowel disease, which mainly depends on clinical symptoms, blood testing, imaging investigations, and endoscopic examination, which includes histology. Endoscopic Ultrasonography is a digestive tract examination technique that combines endoscopy and ultrasound. Compared to conventional endoscopy, it can visualize surface and deep lesions of the gastrointestinal wall, as well as provide information on the characteristics of the surrounding layers and nearby lymph nodes. Due to these advantages, Endoscopic Ultrasonography has played a significant role in the evaluation of inflammatory bowel disease in recent years. Through this work, we aim to identify the applications of this method in the case of patients with inflammatory bowel disease.

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.

Computed tomography enterography radiomics and machine learning for identification of Crohn's disease

BACKGROUND

Crohn's disease is a severe chronic and relapsing inflammatory bowel disease. Although contrast-enhanced computed tomography enterography is commonly used to evaluate crohn's disease, its imaging findings are often nonspecific and can overlap with other bowel diseases. Recent studies have explored the application of radiomics-based machine learning algorithms to aid in the diagnosis of medical images. This study aims to develop a non-invasive method for detecting bowel lesions associated with Crohn's disease using CT enterography radiomics and machine learning algorithms.

METHODS

A total of 139 patients with pathologically confirmed Crohn's disease were retrospectively enrolled in this study. Radiomics features were extracted from both arterial- and venous-phase CT enterography images, representing both bowel lesions with Crohn's disease and segments of normal bowel. A machine learning classification system was constructed by combining six selected radiomics features with eight classification algorithms. The models were trained using leave-one-out cross-validation and evaluated for accuracy.

RESULTS

The classification model demonstrated robust performance and high accuracy, with an area under the curve of 0.938 and 0.961 for the arterial- and venous-phase images, respectively. The model achieved an accuracy of 0.938 for arterial-phase images and 0.961 for venous-phase images.

CONCLUSIONS

This study successfully identified a radiomics machine learning method that effectively differentiates Crohn's disease bowel lesions from normal bowel segments. Further studies with larger sample sizes and external cohorts are needed to validate these findings.

Developing a Reproducible Radiomics Model for Diagnosis of Active Crohn's Disease on CT Enterography Across Annotation Variations and Acquisition Differences

To systematically identify radiomics features on CT enterography (CTE) scans which can accurately diagnose active Crohn's disease across multiple sources of variation. Retrospective study of CTE scans curated between 2013 and 2015, comprising 164 subjects (65 male, 99 female; all patients were over the age of 18) with endoscopic confirmation for the presence or absence of active Crohn's disease. All patients had three distinct sets of scans available (full and reduced dose, where the latter had been reconstructed via two different methods), acquired on a single scanner at a single institution. Radiomics descriptors from annotated terminal ileum regions were individually and systematically evaluated for resilience to different imaging variations (changes in dose/reconstruction, batch effects, and simulated annotation differences) via multiple reproducibility measures. Multiple radiomics models (by accounting for each source of variation) were evaluated in terms of classifier area under the ROC curve (AUC) for identifying patients with active Crohn's disease, across separate discovery and hold-out validation cohorts. Radiomics descriptors selected based on resiliency to multiple sources of imaging variation yielded the highest overall classification performance in the discovery cohort (AUC = 0.79 ± 0.04) which also best generalized in hold-out validation (AUC = 0.81). Performance was maintained across multiple doses and reconstructions while also being significantly better (p < 0.001) than non-resilient descriptors or descriptors only resilient to a single source of variation. Radiomics features can accurately diagnose active Crohn's disease on CTE scans across multiple sources of imaging variation via systematic analysis of reproducibility measures. Clinical utility and translatability of radiomics features for diagnosis and characterization of Crohn's disease on CTE scans will be contingent on their reproducibility across multiple types and sources of imaging variation.

Magnetic Resonance Enterography and Intestinal Ultrasound for the Assessment and Monitoring of Crohn's Disease

Magnetic resonance enterography [MRE] and intestinal ultrasound [IUS] have developed rapidly in the past few decades, emerging as the primary non-invasive options for both diagnosing and monitoring Crohn's disease [CD]. In this review, we evaluate the pertinent data relating to the use of MRE and IUS in CD. We summarise the key imaging features of CD activity, highlight their increasing role in both the clinical and the research settings, and discuss how these modalities fit within the diagnostic pathway. We discuss how they can be used to assess disease activity and treatment responsiveness, including the emergence of activity scores for standardised reporting. Additionally, we address areas of controversy such as the use of contrast agents, the role of diffusion-weighted imaging, and point-of-care ultrasound. We also highlight exciting new developments, including the applications of artificial intelligence. Finally, we provide suggestions for future research priorities.

Substantial cost savings of ultrasound-based management over magnetic resonance imaging-based management in an inflammatory bowel disease service

BACKGROUND

Imaging is used to monitor disease activity in small bowel Crohn's disease (CD). Magnetic Resonance Enterography is often employed as a first modality in the United Kingdom for assessment and monitoring; however, waiting times, cost, patient burden and limited access are significant. It is as yet uncertain if small bowel intestinal ultrasound (IUS) may be a quicker, more acceptable, and cheaper alternative for monitoring patients with CD.

METHODS

A clinical service evaluation of imaging pathways was undertaken at a single NHS site in England, United Kingdom. Data were collected about patients who were referred and underwent an imaging analysis for their IBD. Only patients who underwent a therapy change were included in the analysis. Data were collected from care episodes between 01 January 2021-30 March 2022.

RESULTS

A combined total of 193 patient care episodes were reviewed, 107 from the IUS pathway and 86 from the MRE pathway. Estimated costs per patient in the IUS pathway was £78.86, and £375.35 per patient in the MRE pathway. The MRE pathway had an average time from referral to treatment initiation of 91 days (SD= ±61) with patients in the IUS pathway waiting an average of 46 days (SD= ±17).

CONCLUSIONS

Findings from this work indicate that IUS is a potential cost-saving option when compared to MRE when used in the management of CD. This is in addition to the cost difference of the radiological modalities. A large, multicentre, prospective study is needed to validate these initial findings.

Determining the Accuracy of Intestinal Ultrasound Scores as a Prescreening Tool in Crohn's Disease Clinical Trials

INTRODUCTION

High rates of screen failure for the minimum Simple Endoscopic Score for Crohn's Disease (SES-CD) plague Crohn's disease (CD) clinical trials. We aimed to determine the accuracy of segmental intestinal ultrasound (IUS) parameters and scores to detect segmental SES-CD activity.

METHODS

A single-center, blinded, cross-sectional cohort study of children and young adult patients with CD undergoing IUS and ileocolonoscopy, comparing segmental IUS bowel wall thickness (BWT), hyperemia (modified Limberg score [MLS]), and scores to detect segmental SES-CD activity: (i) SES-CD ≤2, (ii) SES-CD ≥6, and (iii) SES-CD ≥4 in the terminal ileum (TI) only. Primary outcome was accuracy of BWT, MLS, and IUS scores to detect SES-CD ≤2 and SES-CD ≥6. Secondary outcomes were accuracy of TI BWT, MLS, and IUS scores to detect SES-CD ≥4 and correlation with the SES-CD.

RESULTS

Eighty-two patients (median [interquartile range] age 16.5 [12.9-20.0] years) underwent IUS and ileocolonoscopy of 323 bowel segments. Segmental BWT ≤3.1 mm had a similar high accuracy to detect SES-CD ≤2 as IUS scores (area under the receiver operating curve [AUROC] 0.833 [95% confidence interval 0.76-0.91], 94% sensitivity, and 73% specificity). Segmental BWT ≥3.6 mm and ≥4.3 mm had similar high accuracy to detect SES-CD ≥6 (AUROC 0.950 [95% confidence interval 0.92-0.98], 89% sensitivity, 93% specificity) in the colon and an SES-CD ≥4 in the TI (AUROC 0.874 [0.79-0.96], 80% sensitivity, and 91% specificity) as IUS scores. Segmental IUS scores strongly correlated with the SES-CD.

DISCUSSION

Segmental IUS BWT is highly accurate to detect moderate-to-severe endoscopic inflammation. IUS may be the ideal prescreening tool to reduce unnecessary trial screen failures.

Influence of diffusion weighted imaging and contrast enhanced T1 sequences on the diagnostic accuracy of magnetic resonance enterography for Crohn's disease

OBJECTIVES

To evaluate the additional diagnostic benefit of diffusion weighted imaging (DWI) and contrast enhanced (CE) images during MR enterography (MRE) of Crohn's disease.

METHODS

Datasets from 73 patients (mean age 32; 40 male) (28 new-diagnosis, 45 relapsed) were read independently by two radiologists selected from a pool of 13. Radiologists interpreted datasets using three sequential sequence blocks: (1) T2 weighted and steady state free precession gradient echo (SSFP) images alone (T2^); (2) T2 weighted and SSFP images with DWI (T2 + DWI^) and; (3) T2 weighted images, SSFP, DWI and post-contrast enhanced (CE) T1 images (T2 + DWI + CE^), documenting presence, location, and activity of small bowel disease. For each sequence block, sensitivity and specificity (readers combined) was calculated against an outcome-based construct reference standard.

RESULTS

59/73 patients had small bowel disease. Per-patient sensitivity for disease detection was essentially identical (80 % [95 % CI 72, 86], 81 % [73,87], and 79 % [71,86] for T2^, T2 + DWI^and T2 + DWI + CE^respectively). Specificity was identical (82 % [64 to 92]). Per patient sensitivity for disease extent was 56 % (47,65), 56 % (47,65) and 52 % (43 to 61) respectively, and specificity was 82 % (64 to 92) for all blocks. Sensitivity for active disease was 97 % (90,99), 97 % (90,99) and 98 % (92,99), and specificity was also comparable between all sequence combination reads. Results were consistent across segments and newly diagnosed/relapse patients.

CONCLUSION

There is no additional diagnostic benefit of adding either DWI or CE to T2 FSE and SSFP sequences for evaluating small bowel Crohn's disease, suggesting MRE protocols can be simplified safely.

Consenso colombiano de la enfermedad inflamatoria intestinal pediátrica

Introducción: la colitis ulcerativa pediátrica (CUP), la enfermedad de Crohn pediátrica (ECP) y la enfermedad inflamatoria intestinal pediátrica no clasificable (EIIPNC) tienen particularidades clínicas y psicosociales que las diferencian de las del adulto y pueden condicionar enfoques terapéuticos distintos por las posibles repercusiones nutricionales, crecimiento y desarrollo, lo que representa un desafío para el pediatra y el gastroenterólogo. Objetivo: desarrollar recomendaciones basadas en la evidencia por consenso de expertos para el diagnóstico y el tratamiento oportunos y seguros de la enfermedad inflamatoria intestinal pediátrica (EIIP) en menores de 18 años, para los profesionales que atienden estos pacientes y los pagadores en salud. Metodología: a través de un panel de expertos del Colegio Colombiano de Gastroenterología, Hepatología y Nutrición Pediátrica (COLGAHNP) y un grupo multidisciplinario se formularon 35 preguntas en relación con el cuadro clínico, el diagnóstico y el tratamiento de la EIIP. A través de una revisión y un análisis crítico de la literatura, con especial énfasis en las principales guías de práctica clínica (GPC), estudios clínicos aleatorizados (ECA) y metaanálisis de los últimos 10 años, los expertos plantearon 77 recomendaciones que respondían a cada una de las preguntas de investigación con sus respectivos puntos prácticos. Posteriormente, cada una de las afirmaciones se sometieron a votación dentro del grupo desarrollador, incluyendo las afirmaciones que alcanzaron > 80 %. Resultados: todas las afirmaciones alcanzaron una votación > 80 %. La EIIP tiene mayor extensión, severidad y evolución hacia la estenosis, enfermedad perianal, manifestaciones extraintestinales y retraso en el crecimiento en comparación con los pacientes adultos, por lo que su manejo debe ser realizado por grupos multidisciplinarios liderados por gastroenterólogos pediatras y prepararlos para una transición a la edad adulta. Los criterios de Porto permiten una clasificación práctica de la EIIP. En la ECP, debemos usar la clasificación de París y debemos realizar ileocolonoscopia y esofagogastroduodenoscopia, ya que el 50 % tienen un compromiso superior, usando el SES-CD (UCEIS/Mayo en CUP) y tomando múltiples biopsias. Los laboratorios iniciales deben incluir marcadores de inflamación, calprotectina fecal y descartar infecciones intestinales. El tratamiento, la inducción y el mantenimiento de la EIIP deben ser individualizados y decididos según la estratificación de riesgo. En el seguimiento se debe usar el Pediatric Crohn Disease Activity Index (PCDAI) y Pediatric Ulcerative Colitis Activity Index (PUCAI) de las últimas 48 horas. Los pacientes con EIIP temprana e infantil, deben ser valorados por inmunólogos y genetistas. Conclusión: se proporciona una guía de consenso con recomendaciones basadas en la evidencia sobre el diagnóstico y los tratamientos oportunos y seguros en los pacientes con EIIP.

Assessment of Ileal Crohn's Disease Activity by Gastrointestinal Ultrasound and MR Enterography: A Pilot Study

INTRODUCTION

In some cases, there may be a discrepancy between the symptomatology alleged by Crohn's disease (CD) patients and the results of laboratory tests or imaging investigations. Ileocolonoscopy with biopsy is the primary investigation for diagnosing and monitoring CD patients. Cross-sectional imaging techniques such as CT or MR enterography (MRE) and intestinal ultrasonography (IUS) have been proposed as complementary methods to colonoscopy for a complete evaluation of this category of patients. This study aims to identify the role of IUS, contrast-enhanced ultrasound (CEUS) and MRE in evaluating ileal CD activity, using clinical severity scores (Crohn's disease activity index-CDAI, Harvey-Bradshaw index-HBI) and faecal calprotectin or C-reactive protein (CRP) levels as reference methods.

MATERIALS AND METHODS

A total of 44 adult patients with ileal CD confirmed using an ileocolonoscopy with biopsy and histopathological examination were assessed by IUS, CEUS and MRE. The evaluation of the disease activity based on the results obtained from the cross-sectional imaging tests was carried out by using some severity scores available in the literature. The sensitivity and specificity of IUS + CEUS and MRE for differentiating active from inactive forms of CD were determined using CDAI, HBI, faecal calprotectin and CRP as reference methods. The accuracy of the results was assessed by the receiver operating characteristics method. The Pearson correlation coefficient was used to determine the types of correlation. A p-value less than 0.05 suggested a statistically significant relationship.

RESULTS

Compared to CDAI, the best correlation was identified for Limberg score (r = 0.667, 95% confidence interval (CI) [0.46, 0.8], p < 0.001), followed by MaRIAs score (r = 0.614, 95% CI [0.39, 0.77], p < 0.001). A sensitivity of 93.33% and a specificity of 71.43% (AUC = 0.98) were demonstrated in the case of Limberg score for differentiating patients with active disease from those in remission and for MaRIAs score a sensitivity of 100.00% and a specificity of 57.14% (AUC = 0.97). Regarding HBI, the best correlation was observed for MaRIAs score (r = 0.594, 95% CI [0.36, 0.76], p < 0.001). Also, faecal calprotectin showed the best correlation with MaRIAs score (r = 0.697, 95% CI [0.46, 0.84], p < 0.001), but in the case of CRP, there was only a weak correlation for all evaluated scores.

CONCLUSIONS

Although magnetic resonance imaging does not appear to be superior to ultrasonography in terms of accuracy for differentiating active forms of CD from those in remission, the results of our study suggest that MRE associates a better correlation with clinical severity scores and faecal calprotectin levels compared to ultrasonography. More studies are needed to validate these results.

[New solutions for an old problem : Current developments in oral contrast agents]

BACKGROUND

Several radiological societies in Europe have so far spoken out in favor of MRI of the small intestine over CT, since MRI is said to provide more detailed image information. Due to the limited availability of MRI machines, long waiting times arise for many patients who clinically require small bowel imaging.

OBJECTIVES

These circumstances guided our search for an improved CT technique that would provide scans that mimic the image impression of T1 sequence in MRI, i.e. with IV contrast-enhanced intestinal wall versus low/no signal lumen.

MATERIAL AND METHODS

The oral use of fat or oil is poorly tolerated by patients, as is the placement of a naso-duodenal tube for air insufflation. We have now succeeded in creating a foamy drink with 44% air content, which is kept stable by protein together with buffers, and can be easily administered orally. CT with the Lumentin® beverage as bowel filling agent has been tested on healthy adult volunteers; oncology patients; and Crohn's disease patients who, for comparison, also underwent MRI of the small bowel with conventional oral contrast.

RESULTS

The results so far with Lumentin® show a very good distribution throughout the entire small intestine with good lumen distension, images with strongly enhanced contrast of the intestinal mucosa, and lesions that are detected at the same or increased frequency as compared with MRI. Side effects were few and mild, and overall fewer than with commonly used oral agents. Lumentin's foamy consistency was unfamiliar to a few patients, but it wasn't difficult to drink.

CONCLUSIONS

The new and innovative luminal HU-negative contrast agent Lumentin® improves the diagnostic CT image quality. In addition, Lumentin® experimental MRI tests have provided promising results, which are currently leading to further clinical MRI studies.

Clinical significance of a novel uric-acid-based biomarker in the prediction of disease activity and response to infliximab therapy in Crohn's disease

OBJECTIVES

Crohn's disease (CD) is an inflammatory bowel disease marked by a chronic remission-relapse cycle. Biomarkers are critical to reflect the bowel wall inflammation and detect the treatment response. Here, we investigated a new index-the ratio of neutrophil to uric acid (NUR)-as a predictor of CD activity and responses to infliximab (IFX) treatment.

METHODS

Clinical and laboratory data were retrieved for CD patients and healthy control subjects from an electronic medical records database. Disease and endoscopic activity were determined using the Crohn's Disease Activity Index (CDAI) and Simple Endoscopic Score for Crohn's Disease (SES-CD), respectively.

RESULTS

We found firstly that NUR was remarkably higher in CD patients (n = 162) than controls (n = 170) (0.27 ± 0.10 vs. 0.19 ± 0.04, p < .0001). NUR was positively correlated with disease activity and prior to treatment, it was lower in CD patients who responded to IFX than in those who did not (0.25 ± 0.07 vs. 0.38 ± 0.12, p = .0019). Pre-treatment NUR was effective in predicting the patients' responses to IFX (AUC = 0.8469, p = .0034).

CONCLUSION

The results of this study support the utility of NUR for detecting CD activity and predicting the response to IFX treatment.

Treatment escalation and de-escalation decisions in Crohn's disease: Delphi consensus recommendations from Japan, 2021

BACKGROUND

We aimed to develop criteria for treatment intensification in patients with (1) luminal Crohn's disease (CD), (2) CD with perianal disease and/or fistula, (3) CD with small bowel stenosis, (4) in the postoperative setting, and (5) for discontinuing or reducing the dose of treatment in patients with CD.

METHODS

PubMed and Embase were searched for studies published since 1998 which may be relevant to the five defined topics. Results were assessed for relevant studies, with preference given to data from randomized, controlled studies. For each question, a core panel of 12 gastroenterologists defined the treatment target and developed statements, based on the literature, current guidelines, and relevant additional studies. The evidence supporting each statement was graded using the Oxford Centre for Evidence-Based Medicine: Levels of Evidence (March 2009). A modified Delphi process was used to refine statements and gain agreement from 54 Japanese specialists at in-person and online meetings conducted between October 2020 and April 2021.

RESULTS

Seventeen statements were developed for treatment intensification in luminal CD (targeting endoscopic remission), six statements for treatment intensification in perianal/fistulizing CD (targeting healing of perianal lesions and complete closure of the fistula), six statements for treatment intensification in CD with small bowel stenosis (targeting resolution of obstructive symptoms), seven statements for treatment intensification after surgery (targeting endoscopic remission), and five statements for discontinuing or reducing the dose of treatment in patients with CD.

CONCLUSIONS

These statements provide guidance on how and when to intensify or de-intensify treatment for a broad spectrum of patients with CD.

Related Factors for Unfavorable Disease Course in Patients with Crohn's Disease: An Observational Retrospective Study

Background: Crohn’s disease (CD) manifests a heterogeneous clinical spectrum and disease course, and it is challenging to predict the disease outcome based on initial presentation. Objective: To analyze the long-term disease course and factors leading to poor prognosis of CD. Methods: In total, 112 patients with CD who were initially diagnosed and treated at our institution from January 2009 to August 2020 were included. We analyzed their clinical data, disease characteristics according to the Montreal classification, and the endoscopic and computed tomography (CT) examinations at the initial visit and at 2-year, 5-year, and last follow ups. We categorized the disease course into the following four categories: remission, stable, chronic refractory, and chronic relapsing. Significant factors associated with a poorer prognosis were analyzed. Results: The median follow-up period was 107 (range, 61−139) months. Complicated disease behavior increased slightly over the follow-up period (20.5% to 26.2%). An unfavorable disease course was defined as chronic refractory (19.6%) and relapsing (16.1%) courses. The 2-year disease characteristics were significant factors for unfavorable disease course, and the combination of 2-year perianal disease and 2-year moderate-to-severe CT activity could predict unfavorable disease course with the highest accuracy (0.722; area under the curve: 0.768; p < 0.0001). Conclusions: One-third of the patients with CD showed an unfavorable disease course (35.7%), and 2-year disease characteristics were significant factors for an unfavorable disease course.

Recent advances in clinical practice: advances in cross-sectional imaging in inflammatory bowel disease

Endoscopy remains the reference standard for the diagnosis and assessment of patients with inflammatory bowel disease (IBD), but it has several important limitations. Cross-sectional imaging techniques such as magnetic resonance enterography (MRE) and intestinal ultrasound (IUS) are better tolerated and safer. Moreover, they can examine the entire bowel, even in patients with stenoses and/or severe inflammation. A variety of cross-sectional imaging activity scores strongly correlate with endoscopic measures of mucosal inflammation in the colon and terminal ileum. Unlike endoscopy, cross-sectional techniques allow complete visualisation of the small-bowel and assess for extraintestinal disease, which occurs in nearly half of patients with IBD. Extramural findings may predict outcomes better than endoscopic mucosal assessment, so cross-sectional techniques might help identify more relevant therapeutic targets. Coupled with their high sensitivity, these advantages have made MRE and IUS the primary non-invasive options for diagnosing and monitoring Crohn's disease; they are appropriate first-line investigations, and have become viable alternatives to colonoscopy. This review discusses cross-sectional imaging in IBD in current clinical practice as well as research lines that will define the future role of these techniques.

Serial Changes in Body Composition and the Association with Disease Activity during Treatment in Patients with Crohn's Disease

Objectives: To analyze serial changes in body composition and investigate the association between body composition changes and disease activity changes in patients with Crohn’s disease (CD). Methods: Seventy-one patients with CD who had been treated and followed-up at our institution were included. Two to four computed tomography images were acquired at baseline, and the 2−5-year, 5−8-year, and last follow-ups were selected per patient for body composition and disease activity analyses. Visceral fat area (VFA), skeletal muscle index (SMI; skeletal muscle area/height2), and subcutaneous fat area (SFA) were assessed using an artificial-intelligence-driven fully automated method. Disease activity was assessed using a modified computed tomography scoring system and the Simple Endoscopic Score for Crohn’s Disease. The associations between body composition, disease activity, and remission were investigated. Results: The mean age was 29.83 ± 11.27 years; most patients were men (48/71, 67.6%); and the median follow-up was 144 (12−264) months. Overall, VFA and SFA gradually increased, while SMI decreased during the follow-up. Sarcopenia was associated with the female sex, higher disease activities at baseline (p = 0.01) and the last follow-up (p = 0.001). SMI and SFA inversely correlated with the disease activity, i.e., the more severe the disease activity, the lower the SMI and SFA (p < 0.05). SMI at the last follow-up was the only significant predictor of remission (OR = 1.21, 95% confidence interval: 1.03−1.42, p = 0.021). Conclusion: SMI decreased while VFA and SFA increased during the treatment follow-up in patients with CD. Sarcopenia was associated with higher disease activity, and SMI and SFA inversely correlated with disease activity. SMI at the last follow-up was the significant factor for remission.

Correlation between magnetic resonance enterography and ileo-colonoscopy for assessment of disease activity in terminal ileal Crohn's disease

BACKGROUND

Magnetic resonance enterography (MRE) has emerged as a novel tool for the assessment of disease activity in Crohn's disease (CD). Real world data from Indian subcontinent on performance of MRE in terminal ileal CD are lacking.

METHODS

Retrospective analysis of patients with terminal ileal CD who underwent both ileo-colonoscopy and MRE was performed. Ileo-colonoscopy was considered the gold standard for assessment of disease activity. On ileo-colonoscopy, a simple endoscopic score for Crohn's disease (SES-CD) ≥2 was considered active disease; presence of ulcers indicated severe disease. MRE scoring of the disease activity was performed using magnetic resonance index of activity (MARIA) and simplified MARIA (MARIAs). The measure of agreement between ileo-colonoscopy and MRE and comparison of MARIA and MARIAs for assessment of disease activity and sensitivity of MRE to detect mucosal ulcerations were calculated.

RESULTS

Seventy patients with terminal ileal CD (mean age 40.74±15.56 years; 71.4% males [n=50]) were evaluated. The sensitivities of MARIA and MARIAs scores to detect active disease were 0.76 and 0.84, respectively. The area under the receiver operating characteristic curve (AUROC) for detecting severe disease was 0.836 (p<0.0001) for MARIA and 0.861 (p<0.0001) for MARIAs. For mild active disease, there was no agreement between SES-CD and MARIA or MARIAs; however, for severe disease, the agreement was fair and moderate for MARIA and MARIAs, respectively. MARIA and MARIAs were comparable for identification of active and severe disease (κ 0.759, p<0.0001 and κ 0.840, p<0.0001, respectively). MRE was 68.18% sensitive to detect mucosal ulcers.

CONCLUSION

MRE is a reliable and sensitive tool for detection of endoscopically severe, but not mild, terminal ileal CD.

10-Year Trend of Abdominal Magnetic Resonance Imaging Compared With Abdominal Computed Tomography Scans in Inflammatory Bowel Disease

BACKGROUND

Patients with inflammatory bowel disease (IBD) frequently undergo multiple computed tomography (CT) examinations. With the widespread availability of magnetic resonance imaging (MRI), it is unclear whether the use of CTs in IBD has declined. We aimed to analyze the trends of CT and MRI use in a large cohort of IBD patients in a 10-year period.

METHODS

We retrospectively analyzed adults ≥18 years of age using a de-identified database, IBM Explorys. Patients with ≥1 CT of the abdomen (± pelvis) or MRI of the abdomen (± pelvis) at least 30 days after the diagnosis of Crohn's disease (CD) or ulcerative colitis (UC) were included. We examined the factors associated with patients undergoing multiple CTs (≥5 CTs of the abdomen) and performed a trend analysis from 2010 to 2019.

RESULTS

Among 176 110 CD and 143 460 UC patients, those with ≥1 CT of the abdomen annually increased from 2010 to 2019 with mean annual percentage change of +3.6% for CD and +4.9% for UC. Similarly, annual percentage change for patients with ≥1 MRI (CD: +15.6%; UC: +22.8%) showed a rising trend. There was a 3.8% increase in CD patients receiving ≥5 CTs of the abdomen annually compared with a 2.4% increase among UC patients in the 10-year period. Age ≥50 years, men, African Americans, public insurance payors, body mass index ≥30kg/m2, and smoking history were associated with ≥5 CTs.

CONCLUSIONS

There is a considerable increase in the number of CT scans performed in IBD patients. Further studies can explore factors influencing the use of CT and MRI of the abdomen in IBD patients.

Treat to transmural healing: how to incorporate intestinal ultrasound into the treatment of inflammatory bowel disease

Intestinal ultrasound (IUS) is emerging as a key tool to achieving the therapeutic target of transmural healing in inflammatory bowel disease (IBD). IUS is a non-invasive, radiation-free, imaging modality comparable to MRI, CT and ileocolonoscopy (IC). With the appropriate training and equipment, IUS can be an easily repeatable bedside test for IBD diagnosis and disease monitoring, including treatment response. Core to successful high quality IUS employment are appropriate training and expert techniques; however, the training pathway will not be explored in this review. Given the increasing shift towards objective assessment for tight disease control, gastroenterologist-led IUS should be incorporated into the armamentarium of imaging modalities alongside radiologists, to enhance our diagnostic and monitoring toolbox. This comprehensive review aims to outline the current literature around IUS and propose the placement of IUS in a treat-to-target algorithm in IBD. Ultimately, IUS facilitates timely management decisions to optimise patient care with potential to revolutionise patient outcomes, moving towards transmural healing as the holy grail of therapy in IBD.

Dual energy computed tomography in Crohn's disease: a targeted review

INTRODUCTION

Crohn's disease (CD) is a common chronic inflammatory bowel disease characterized by transmural inflammation and extra-intestinal complications. The diagnosis of CD is made using a combination of clinical, biochemical, endoscopic, imaging and histological features. Among imaging methods, computed tomography enterography (CTE) is the most commonly used. Dual-energy CTE allows objective evaluation of patients with CD. Along with the findings seen in conventional CTE, dual-energy CTE can generate iodine density maps and quantify the iodine content in the involved segments of the bowel, thus providing a measure of the perfusion of the affected bowel. In addition, the virtual monochromatic images generated from dual-energy CTE allow better qualitative evaluation of the mural and extramural findings.

AREAS COVERED

We performed a targeted systemic review of all the studies in the literature to understand the role of dual-energy CT in the diagnosis and assessment of the severity of CD.

EXPERT OPINION

Dual-energy CTE is superior to conventional CTE in the evaluation of CD. Besides quantifying iodine in the pathological segments, other quantitative parameters like the mural thickness of affected bowel segments, the number of segments involved, ulcerations, comb sign, lymphadenopathy, and the mural heterogeneity can also be assessed in dual-energy CTE.

Role of Dual Energy Computed Tomography in Inflammatory Bowel Disease

Dual-energy computed tomography (DECT), which allows material-based differential X-ray absorption behavior from near simultaneously acquired low- and high-kilovolt datasets is finding increasing applications in the evaluation of bowel diseases. In patients with inflammatory bowel disease, DECT techniques permit both qualitative and quantitative assessment. Particularly in patients with Crohn's disease, monoenergetic and iodine specific images have been explored. This article focuses on the principles and applications of DECT in inflammatory bowel disease along with review of its limitations and challenges.

Diagnostic Performance of Magnetic Resonance Enterography Disease Activity Indices Compared with a Histological Reference Standard for Adult Terminal Ileal Crohn's Disease: Experience from the METRIC Trial

BACKGROUND AND AIMS

The simplified magnetic resonance enterography [MRE] index of activity [sMARIA], London, and 'extended' London, scoring systems are widely used in Crohn's disease [CD] to assess disease activity, although validation studies have usually been single-centre, retrospective, and/or used few readers. Here, we evaluated these MRE indices within a prospective, multicentre, multireader, diagnostic accuracy trial.

METHODS

A subset of participants [newly diagnosed or suspected of relapse] recruited to the METRIC trial with available terminal ileal [TI] biopsies was included. Using pre-specified thresholds, the sensitivity and specificity of sMARIA, London, and 'extended' London scores for active and severe [sMARIA] TI CD were calculated using different thresholds for the histological activity index [HAI].

RESULTS

We studied 111 patients [median age 29 years, interquartile range 21-41, 75 newly diagnosed, 36 suspected relapse] from seven centres, of whom 22 had no active TI CD [HAI = 0], 39 mild [HAI = 1], 13 moderate [HAI = 2], and 37 severe CD activity [HAI = 3]. In total, 26 radiologists prospectively scored MRE datasets as per their usual clinical practice. Sensitivity and specificity for active disease [HAI >0] were 83% [95% confidence interval 74% to 90%] and 41% [23% to 61%] for sMARIA, 76% [67% to 84%] and 64% [43% to 80%] for the London score, and 81% [72% to 88%] and 41% [23% to 61%] for the 'extended' London score, respectively. The sMARIA had 84% [69-92%] sensitivity and 53% [41-64%] specificity for severe CD.

CONCLUSIONS

When tested at their proposed cut-offs in a real-world setting, sMARIA, London, and 'extended' London indices achieve high sensitivity for active TI disease against a histological reference standard, but specificity is low.

Interobserver variation in the interpretation of magnetic resonance enterography in Crohn's disease

OBJECTIVES

To evaluate interobserver variability for diagnosis of disease presence and extent of small bowel and colonic Crohn's disease using MR enterography (MRE).

METHODS

Data from the first 73 consecutive patients (mean age 32, 33F, 28 new diagnosis, 45 suspected relapse) recruited to a multicentre, prospective diagnostic accuracy trial evaluating MRE for small bowel Crohn's disease were each read independently by three (from a pool of 20) radiologists. Radiologists documented presence and segmental location of small bowel Crohn's disease and recorded morphological mural/extramural parameters for involved segments. Per patient percentage agreement for disease presence and extent were calculated against an outcome-based construct reference standard (averaged between pairs of readers). Prevalence-adjusted bias-adjusted κ (PABAK) was calculated.

RESULTS

Agreement for small bowel disease presence for new diagnosis/relapsed patients was 68%(κ = 0.36)/ 78% (κ = 0.56) and 43%(κ = 0.14)/ 53% for disease extent (κ = 0.07), respectively. For disease presence, all three radiologists agreed correctly with the reference standard in 41/59 (69%) of patients with small bowel involvement, and in 8/14 (57%) cases of without small bowel disease. Agreement was highest for multisegment disease, greater than 5 cm in length, with mural thickness>6 mm, and increased mural T2 signal. Agreement for colonic disease presence was 61% (κ = 0.21 fair agreement) for new diagnosis/ 60% (κ = 0.20, slight agreement) for relapsed patients.

CONCLUSION

There is a reasonable agreement between radiologists for small bowel disease presence using MRE for newly diagnosed Crohn's disease, and patients with suspected relapse, respectively. Agreement is lower for disease extent.

ADVANCES IN KNOWLEDGE

There is reasonable agreement between radiologists for small bowel disease presence using MRE for newly diagnosed (68%) Crohn's disease, and patients with suspected relapse (78%). Agreement is lower for disease extent (43% new diagnosis and 53% suspected relapse).

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.

Small bowel Crohn's disease: optimal modality for diagnosis and monitoring

PURPOSE OF REVIEW

This paper reviews different imaging options for small bowel (SB) Crohn's disease (CD) patients.

RECENT FINDINGS

In total, 80% of patients suffering from CD have SB involvement, being the exclusive manifestation in 30% of cases. As the proximal disease is related to poor response to treatment, a higher rate of stenosis and a greater need for surgical treatment, a SB assessment should be performed. This evaluation should be done not only once the disease has been diagnosed but periodically. The former to determine the extent of the disease, and the latter according to a treat-to-target strategy. Available techniques such as magnetic resonance imaging, intestinal ultrasound and capsule endoscopy (CE) have shown good accuracy parameters in CD patients. Cross-sectional studies are superior for penetrating and stricturing disease, whereas CE is excellent for proximal involvement and mucosal healing. Local expertise and availability may lead the election between techniques, nevertheless, they should not be considered as competitors but as complementary tools.

SUMMARY

SB involvement in CD patients is frequent and related to poorer outcomes. Hence, SB evaluation should be screened after diagnosis and routinely during the follow-up.

ACR Appropriateness Criteria® Crohn Disease-Child

Crohn disease is an inflammatory condition of the gastrointestinal tract with episodes of exacerbation and remission occurring in children, adolescents, and adults. Crohn disease diagnosis and treatment depend upon a combination of clinical, laboratory, endoscopic, histological, and imaging findings. Appropriate use of imaging provides critical information in the settings of diagnosis, assessment of acute symptoms, disease surveillance, and therapy monitoring. Four variants are discussed. The first variant discusses the initial imaging for suspected Crohn disease before established diagnosis. The second variant pertains to appropriateness of imaging modalities during suspected acute exacerbation. The third variant is a substantial discussion of recommendations related to disease surveillance and monitoring of Crohn disease. Finally, panel recommendations and discussion of perianal fistulizing disease imaging completes the document. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Development of a New Index to Assess Small Bowel Inflammation Severity in Crohn's Disease Using Magnetic Resonance Enterography

Background

The severity of small bowel (SB) inflammation in Crohn's disease (CD) patients is a key component of the therapeutic choice. We aimed to develop a SB-CD Magnetic Resonance Enterography (MRE) index of Inflammation Severity (CDMRIS).

Methods

Each gastroenterologist/radiologist pair in 13 centers selected MREs from 6 patients with SB-CD stratified on their perceived MRE inflammation severity. The 78 blinded MREs were allocated through balanced incomplete block design per severity stratum to these 13 pairs for rating the presence/severity of 13 preselected items for each SB 20-cm diseased segment. Global inflammation severity was evaluated using a 100-cm visual analog scale. Reproducibility of recorded items was evaluated. The CDMRIS was determined through linear mixed modeling as a combination of the numbers of segments with lesions highly correlated to global inflammation severity.

Results

Four hundred and forty-two readings were available. Global inflammation severity mean ± SD was 21.0 ± 16.2. The independent predictors explaining 54% of the global inflammation severity variance were the numbers of segments with T1 mild-moderate and severe intensity of enhancement, deep ulceration without fistula, comb sign, fistula, and abscess. Unbiased correlation between CDMRIS and global inflammation severity was 0.76.

Conclusions

The CDMRIS is now available to evaluate the severity of SB-CD inflammation. External validation and sensitivity-to-change are mandatory next steps.

Ultrasound use to assess Crohn's disease in the UK: a survey of British Society of Gastroenterology Inflammatory Bowel Disease Group members

BACKGROUND

Small bowel ultrasound has very good diagnostic accuracy for disease extent, presence and activity in Crohn's Disease, is well tolerated by patients and is cheaper when compared with MRI. However, uptake of ultrasound in the UK is limited.

METHODS

An online survey to assess the current usage of ultrasound throughout the UK was undertaken by BSG IBD group members between 9/06/2021- 25/06/2021. Responses were anonymous.

RESULTS

103 responses were included in the data analysis. Responses came from 66 different NHS trusts from 14 different regions of the UK. All respondents reported that they currently have an MRI service for Crohn's disease, whereas only 31 had an ultrasound service. Average time for results to be reported for MRI scans was reported as between 4- and 6 weeks, with a range of 2 days to 28 weeks. The average time for an ultrasound to be reported was stated as 1-4 weeks, with a range of 0-8 weeks. There was disparity between the reported confidence of clinicians making clinical decisions when using ultrasound compared to MRI. Of those respondents who did not have access to an ultrasound service, 72 stated that they would be interested in developing an ultrasound service.

CONCLUSION

There is an appetite for the uptake of ultrasound in the UK for assessment of Crohn's disease, however, there remains a significant number of UK centres with little or no access to an ultrasound service. Further research is necessary to understand why this is the case.

Cross-Sectional Imaging Instead of Colonoscopy in Inflammatory Bowel Diseases: Lights and Shadows

International guidelines recommend a treat-to-target strategy with a close monitoring of disease activity and therapeutic response in inflammatory bowel diseases (IBD). Colonoscopy (CS) represents the current first-line procedure for evaluating disease activity in IBD. However, as it is expensive, invasive and poorly accepted by patients, CS is not appropriate for frequent and repetitive reassessments of disease activity. Recently, cross-sectional imaging techniques have been increasingly shown as reliable tools for assessing IBD activity. While computed tomography (CT) is hampered by radiation risks, routine implementation of magnetic resonance enterography (MRE) for close monitoring is limited by its costs, low availability and long examination time. Novel magnetic resonance imaging (MRI)-based techniques, such as diffusion-weighted imaging (DWI), can overcome some of these weaknesses and have been shown as valuable options for IBD monitoring. Bowel ultrasound (BUS) is a noninvasive, highly available, cheap, and well accepted procedure that has been demonstrated to be as accurate as CS and MRE for assessing and monitoring disease activity in IBD. Furthermore, as BUS can be quickly performed at the point-of-care, it allows for real-time clinical decision making. This review summarizes the current evidence on the use of cross-sectional imaging techniques as cost-effective, noninvasive and reliable alternatives to CS for monitoring patients with IBD.

Diagnostic accuracy of CT enterography correlated to histopathology in the diagnosis of small bowel Crohn's disease

BACKGROUND

Crohn's disease (CD) is a chronic inflammatory process affecting the gastrointestinal tract, mainly the terminal ileum of small bowel. Although ileocolonoscopy provides good mucosal visualization, it does not allow evaluation of extraluminal abnormalities. Computed tomographic enterography (CTE) is an emerging imaging modality for assessment of small bowel disorders. The study aimed to explore the diagnostic accuracy of CTE in the diagnosis of patients with CD benchmarked against a histopathological reference.

METHODS

A cross-sectional study entailed 126 consecutive patients with known or suspected CD who underwent CTE and biopsy by ileocolonoscopy via retrograde terminal ileum intubation. Spearman's rank was used to test the correlation and Kappa coefficient agreement between CTE and histopathology. Area under the curve (AUC) of receiver operating characteristic (ROC) was used to measure CTE diagnostic accuracy.

RESULTS

The overall sensitivity and specificity of CTE were 93.88% and 85.71%, respectively. The PPV was 95.83%, and the NPV was 80%. The accuracy of CTE indicated an overall probability of correct patient classification of 92.06%. The AUC of the ROC of CTE was 0.898 (P < 0.001). Thus, CTE has a high sensitivity for assessment of small bowel CD. The CTE and histopathological gradings were strongly correlated (Spearman's coefficient = 0.962, P < 0.001). CTE exhibited perfect agreement with histopathology (Kappa coefficient (κ) = 0.847, P < 0.001).

CONCLUSION

CTE is a reliable technique that has high diagnostic accuracy in the assessment of CD. Hence, it may be useful for follow up and for preoperative guidance in treatment planning.

Unmet needs in inflammatory bowel disease

Despite the recent developments in the diagnosis and management of inflammatory bowel diseases (IBD), patients still suffer from disabling bowel symptoms and significant disease complications and many questions remain to improve their care. IBD is a chronic disease, whose management could be divided into the five different stages of chronic diseases, ranging from the pre-treatment evaluation phase to the induction therapy, maintenance therapy, monitor and re-establishment of control and the cessation of the disease. Reconciling these phases with the current unmet needs in IBD could help tailor priorities for research. In this review, some of the unanswered questions in the management of both Crohn’s Disease and Ulcerative Colitis will be addressed, by following this paradigm of chronic diseases’ management.

Multidetector computed tomography: a corner stone imaging modality in evaluation of acute small bowel diseases

Background

The diagnosis of acute small bowel diseases is one of the challenging issues that confronted by the radiologists so accurate diagnosis is essential to determine the appropriate way of management. CT has become the preferred imaging tool to evaluate acute small bowel diseases. Our study aimed to assess the role of MDCT in evaluation of acute abdomen secondary to small bowel origin by identification and differentiation between different acute small bowel pathologies.

Results

Thirty-eight patients presented with acute abdomen of small bowel origin from June 2019 to September 2019. The mean age of incidence was 48 ± 19 years ranged from 4 to 88 years. Males represented by 23 patients (60.5%). Acute exacerbation of inflammatory bowel diseases (Crohn’s disease) represented by (34.2%), small bowel obstruction (31.6%), ischemic bowel diseases (21.1%), small bowel perforation (10.5%) and infectious (TB enteritis) small bowel disease (2.6%). MDCT had an overall high sensitivity (97.3%) in assessment of acute small bowel diseases in correlation with post-operative data and follow-up response to management.

Conclusions

MDCT is a reliable diagnostic imaging tool for assessment of patients with acute abdomen secondary to small bowel origin with high-efficiency in differentiation between different pathological entities that causing acute abdomen.

Crohn's Disease Activity Evaluation by Transabdominal Ultrasonography: Correlation with Double-Balloon Endoscopy

OBJECTIVES

Transabdominal ultrasonography (US) has been reported as a useful tool for evaluating Crohn's disease (CD) activity. Endoscopic findings and Crohn's disease activity index (CDAI) are currently considered the gold standard for assessing CD activity. We assessed the correlation between US and double-balloon endoscopy (DBE), and CDAI for evaluating CD activity.

METHODS

We analyzed patients with CD undergoing US and DBE within 10 days between the procedures. The intestine was divided into four segments and analyzed by the US scoring system (US-CD) and the simple endoscopic score for Crohn's disease (SES-CD). CDAI was compared with US-CD and SES-CD. Spearman's rank correlation coefficient was used for statistical analysis.

RESULTS

Twenty-five patients with CD (11 women, 14 men; mean age 35.4 ± 14.9 years, range 16-65 years) were enrolled. Twenty-four patients received antitumor necrosis factor inhibitor therapy. CDAI was 128.1 (range 36-227). A significant moderate correlation was found between the US-CD and SES-CD in all segments (ρ = .64, P < .01). The US-CD showed a strong correlation with CDAI (ρ = .78, P < .01), whereas the SES-CD showed a moderate correlation (ρ = .55, P < .05).

CONCLUSIONS

US-CD and SES-CD showed a moderate correlation for assessing CD activity. US-CD showed a stronger correlation with CDAI than SES-CD, suggesting that US could more accurately evaluate the disease activity.

Guidelines for the management of patients with Crohn's disease. Recommendations of the Polish Society of Gastroenterology and the Polish National Consultant in Gastroenterology

This paper is an update of the diagnostic and therapeutic recommendations of the National Consultant for Gastroenterology and the Polish Society of Gastroenterology from 2012. It contains 46 recommendations for the diagnosis and treatment, both pharmacological and surgical, of Crohn's disease in adults. The guidelines were developed by a group of experts appointed by the Polish Society of Gastroenterology and the National Consultant in the field of Gastroenterology. The methodology related to the GRADE methodology was used to assess the quality and strength of the available recommendations. The degree of expert support for the proposed statement, assessment of the quality of evidence and the strength of the recommendation was assessed on a 6-point Likert scale. Voting results, quality and strength ratings with comments are included with each statement.

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).

The role of the intestinal ultrasound in Crohn's disease diagnosis and monitoring

Crohn's disease is characterized by persistent or recurrent chronic inflammation that may affect any segment of the gastrointestinal tract. It has an oscillating evolution, with periods of activity alternating with periods of remission. Crohn's disease has a significant impact on the economic status due to its increasing prevalence, often affecting young people. Suitable management for these patients involves frequent evaluations. Even though colonoscopy is the gold standard for the assessment of severity and mucosal healing, it is an invasive maneuver, not easily accepted by patients, and it does not have good repeatability. Intestinal ultrasound has the advantage of being non-irradiating, non-invasive, well-tolerated, cheap, and easy to repeat. Ultrasound parameters such as bowel wall thickness, intestinal wall architecture, intramural vascularisation, proliferation of mesenteric fatty conjunctive tissue, and intraperitoneal fluid can provide good information regarding the severity of the disease, the differentiation between remission and relapse, and its complications. Some of the latest studies show good correlations between ultrasound parameters and inflammation markers (C-reactive protein, fecal calprotectin) and clinical severity scores of Crohn's disease. Consequently, the importance of intestinal ultrasound has increased lately, and recent studies support its use to evaluate the severity of inflammation, differentiate between active disease and relapse, monitor therapy response and guide treatment, evaluate prognosis, and diagnose complications.

Point-of-Care Ultrasound in Inflammatory Bowel Disease

Inflammatory bowel diseases [IBD], including Crohn's disease [CD] and ulcerative colitis [UC], are chronic, relapsing and destructive inflammatory disorders of the gastrointestinal tract which can lead to organ damage and impair quality of life. A 'treat-to-target' strategy based on activity and severity of disease and response to treatment with close monitoring of intestinal inflammation is recommended. Ileocolonoscopy [CS] is considered the first-line procedure for the assessment of IBD, and magnetic resonance enterography [MRE] is the current standard for assessing the small bowel and complications in CD, and has been proposed as an alternative procedure to CS in the evaluation of both ileo-colonic CD and UC. As that both CS and MRE are invasive and expensive procedures and unappealing to patients, they are unfeasible as frequent and repetitive tools for the monitoring of disease activity. Bowel ultrasound [US] represents a well-tolerated, non-invasive and cost-effective modality to manage IBD patients in clinical practice. Compared to CS and MRE, bowel US has been shown to have the same level of accuracy in assessing and monitoring disease activity and severity of both CD and UC. It can be performed at the point-of-care and therefore allow for real-time clinical decision-making. Point-of-care ultrasound [POCUS] is suggested as the stethoscope of the future and is gaining interest and diffusion in the medical field because it can be used for the bedside examination of patients. The aim of this review is to discuss point-of-care bowel ultrasound [POCBUS] in the management of patients with IBD.

Inflammation and fibrosis in Crohn's disease: location-matched histological correlation of small bowel ultrasound features

PURPOSE

To evaluate the utility of mural and extramural sonographic features of Crohn's Disease as potential imaging biomarkers of inflammation and fibrosis against whole-mount histological sections.

METHODS

Twelve Crohn's disease patients (Mean age 35(25-69), 7 males) underwent small bowel ultrasound prior to small bowel resection. Two radiologists in consensus graded multiple parameters including mural, mucosal and submucosal thickness, submucosal/mesenteric echogenicity and clarity and mural Doppler signal in 50 selected bowel cross-sections. Matching with histological sampling sites was facilitated via scanning of the resected specimen. A histopathologist scored acute and chronic inflammation, and fibrosis (using histological scoring systems) following analysis of whole mount block sections. The association between sonographic observations and histopathological scores was examined via univariable and multivariable analysis.

RESULTS

In univariate analyses, bowel wall thickness (regression co-efficient and 95% CI 0.8 (0.3, 1.3) p = 0.001), mesenteric fat echogenicity (8.7(3.0, 14.5) p = 0.005), submucosal layer thickness (7.4(1.2, 13.5) p = 0.02), submucosal layer clarity (4.4(0.6, 8.2) p = 0.02) and mucosal layer thickness (4.6(1.8, 7.4) p = 0.001) were all significantly associated with acute inflammation. Mesenteric fat echogenicity (674(8.67, 52404) p = 0.009), submucosal layer thickness (79.9(2.16, 2951) p = 0.02) and mucosal layer thickness (13.6(1.54, 121) p = 0.02) were significantly associated with chronic inflammation. Submucosal layer echogenicity (p = 0.03), clarity (25.0(1.76, 356) p = 0.02) and mucosal layer thickness (53.8(3.19, 908) p = 0.006) were significantly associated with fibrosis. In multivariate analyses, wall and mucosal thickness remained significantly associated with acute inflammation (p = 0.02), mesenteric fat echogenicity with chronic inflammation (p = 0.009) and mucosal thickness (p = 0.006) with fibrosis.

CONCLUSION

Multiple sonographic parameters are associated with histological phenotypes in Crohn's disease although there is overlap between ultrasonic stigmata of acute inflammation, chronic inflammation and fibrosis.

Evaluation of Crohn's Disease Activity: Development of an Ultrasound Score in a Multicenter Study

OBJECTIVE

Our goal in this multicentric prospective study was 2-fold: first, to test the diagnostic accuracy of ultrasound, color Doppler imaging (CDI), and contrast-enhanced ultrasound (CEUS) in identifying disease activity in patients with Crohn's disease (CD) compared with endoscopy as the reference standard; and, second, to construct a sonographic score that allows disease activity to be detected.

MATERIALS AND METHODS

Seventy-two patients with CD from 3 hospitals underwent within a 30-day period both colonoscopy and ultrasound (US), including mural thickness, CDI, and CEUS, prospectively as part of clinical care. A multivariate analysis was carried out to assess the influence of each of the ultrasound variables in predicting endoscopic activity. We then developed a predictive ultrasound score for disease activity, and a receiver operating characteristic (ROC) curve was constructed to determine the area under the ROC curve (AUC) and the best cut-off score value to discriminate between active and inactive disease.

RESULTS

Sonographic findings that were independent predictors of the presence of active disease at endoscopy were wall thickness, color grade, and contrast parameters. A score based on those variables showed high accuracy in predicting active disease, with an area under the ROC curve of 0.972. A simpler index, without contrast parameters, also showed high accuracy in detecting disease activity (AUC, 0.923).

CONCLUSION

A score based on wall thickness, color Doppler grade, and contrast parameters showed high accuracy in predicting active disease. A score without including the use of contrast agent had practically similar results and is easier to use in monitoring response to treatment.

First United Arab Emirates consensus on diagnosis and management of inflammatory bowel diseases: A 2020 Delphi consensus

Ulcerative colitis and Crohn's disease are the main entities of inflammatory bowel disease characterized by chronic remittent inflammation of the gastrointestinal tract. The incidence and prevalence are on the rise worldwide, and the heterogeneity between patients and within individuals over time is striking. The progressive advance in our understanding of the etiopathogenesis coupled with an unprecedented increase in therapeutic options have changed the management towards evidence-based interventions by clinicians with patients. This guideline was stimulated and supported by the Emirates Gastroenterology and Hepatology Society following a systematic review and a Delphi consensus process that provided evidence- and expert opinion-based recommendations. Comprehensive up-to-date guidance is provided regarding diagnosis, evaluation of disease severity, appropriate and timely use of different investigations, choice of appropriate therapy for induction and remission phase according to disease severity, and management of main complications.

Magnetic resonance enterography compared with ultrasonography in newly diagnosed and relapsing Crohn's disease patients: the METRIC diagnostic accuracy study

BACKGROUND

Magnetic resonance enterography and enteric ultrasonography are used to image Crohn's disease patients. Their diagnostic accuracy for presence, extent and activity of enteric Crohn's disease was compared.

OBJECTIVE

To compare diagnostic accuracy, observer variability, acceptability, diagnostic impact and cost-effectiveness of magnetic resonance enterography and ultrasonography in newly diagnosed or relapsing Crohn's disease.

DESIGN

Prospective multicentre cohort study.

SETTING

Eight NHS hospitals.

PARTICIPANTS

Consecutive participants aged ≥ 16 years, newly diagnosed with Crohn's disease or with established Crohn's disease and suspected relapse.

INTERVENTIONS

Magnetic resonance enterography and ultrasonography.

MAIN OUTCOME MEASURES

The primary outcome was per-participant sensitivity difference between magnetic resonance enterography and ultrasonography for small bowel Crohn's disease extent. Secondary outcomes included sensitivity and specificity for small bowel Crohn's disease and colonic Crohn's disease extent, and sensitivity and specificity for small bowel Crohn's disease and colonic Crohn's disease presence; identification of active disease; interobserver variation; participant acceptability; diagnostic impact; and cost-effectiveness.

RESULTS

Out of the 518 participants assessed, 335 entered the trial, with 51 excluded, giving a final cohort of 284 (133 and 151 in new diagnosis and suspected relapse cohorts, respectively). Across the whole cohort, for small bowel Crohn's disease extent, magnetic resonance enterography sensitivity [80%, 95% confidence interval (CI) 72% to 86%] was significantly greater than ultrasonography sensitivity (70%, 95% CI 62% to 78%), with a 10% difference (95% CI 1% to 18%; p = 0.027). For small bowel Crohn's disease extent, magnetic resonance enterography specificity (95%, 95% CI 85% to 98%) was significantly greater than ultrasonography specificity (81%, 95% CI 64% to 91%), with a 14% difference (95% CI 1% to 27%). For small bowel Crohn's disease presence, magnetic resonance enterography sensitivity (97%, 95% CI 91% to 99%) was significantly greater than ultrasonography sensitivity (92%, 95% CI 84% to 96%), with a 5% difference (95% CI 1% to 9%). For small bowel Crohn's disease presence, magnetic resonance enterography specificity was 96% (95% CI 86% to 99%) and ultrasonography specificity was 84% (95% CI 65% to 94%), with a 12% difference (95% CI 0% to 25%). Test sensitivities for small bowel Crohn's disease presence and extent were similar in the two cohorts. For colonic Crohn's disease presence in newly diagnosed participants, ultrasonography sensitivity (67%, 95% CI 49% to 81%) was significantly greater than magnetic resonance enterography sensitivity (47%, 95% CI 31% to 64%), with a 20% difference (95% CI 1% to 39%). For active small bowel Crohn's disease, magnetic resonance enterography sensitivity (96%, 95% CI 92% to 99%) was significantly greater than ultrasonography sensitivity (90%, 95% CI 82% to 95%), with a 6% difference (95% CI 2% to 11%). There was some disagreement between readers for both tests. A total of 88% of participants rated magnetic resonance enterography as very or fairly acceptable, which is significantly lower than the percentage (99%) of participants who did so for ultrasonography. Therapeutic decisions based on magnetic resonance enterography alone and ultrasonography alone agreed with the final decision in 122 out of 158 (77%) cases and 124 out of 158 (78%) cases, respectively. There were no differences in costs or quality-adjusted life-years between tests.

LIMITATIONS

Magnetic resonance enterography and ultrasonography scans were interpreted by practitioners blinded to clinical data (but not participant cohort), which does not reflect use in clinical practice.

CONCLUSIONS

Magnetic resonance enterography has higher accuracy for detecting the presence, extent and activity of small bowel Crohn's disease than ultrasonography does. Both tests have variable interobserver agreement and are broadly acceptable to participants, although ultrasonography produces less participant burden. Diagnostic impact and cost-effectiveness are similar. Recommendations for future work include investigation of the comparative utility of magnetic resonance enterography and ultrasonography for treatment response assessment and investigation of non-specific abdominal symptoms to confirm or refute Crohn's disease.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN03982913.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 42. See the NIHR Journals Library website for further project information.

Utility of bowel ultrasound in assessing disease activity in Crohn's disease

BACKGROUND

Gastrointestinal ultrasound (GIUS) has been used increasingly for monitoring inflammatory bowel disease (IBD) patients. The aim of this study was to assess the utility of GIUS in assessing disease activity in Crohn's disease (CD).

METHODS

Consecutive patients with CD (diagnosis established for at least 6 months) between July 2017 and July 2018 requiring assessment of disease activity were prospectively assessed by magnetic resonance enterography, colonoscopy (CS), and GIUS within a 2-week period and without any change in ongoing treatment. Features on GIUS which correlated with disease activity were assessed. Sensitivity and specificity of the GIUS in assessing disease activity and localization were calculated.

RESULTS

Thirty-five patients were enrolled in the study. Bowel wall thickness (BWT) ≥ 3 mm and Doppler activity ≥ 2 had the highest sensitivity (100% and 95.6%, respectively) for detecting active disease on CS. BWT ≥ 3 mm had sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 83.3%, 92%, and 100%, respectively for assessing active disease. Combination of median BWT, Doppler activity, and loss of bowel wall stratification correlated with simplified endoscopic score (SES) for CD (r = 0.8, p 0.009) and Harvey-Bradshaw index (HBI, r = 0.76, p 0.04). For localizing active disease in the ileum, GIUS had a sensitivity of 93.7%, 80% for lesions in the right colon, 100% for transverse colon, and 89% for the left colon. Specificity was 100% for ileal and colonic lesions.

CONCLUSION

Loss of stratification, BWT, and Doppler activity in the bowel wall correlate with endoscopic and clinical disease activity in CD. GIUS is a sensitive modality in assessing disease activity in CD.

Development and Validation of a Simple Ultrasound Activity Score for Crohn's Disease

BACKGROUND AND AIMS

To improve management of patients with Crohn's disease, objective measurements of disease activity are needed. Ileocolonoscopy is the current reference standard but has limitations that restrict repeated use. Ultrasonography is potentially useful for activity monitoring, but no validated sonographic activity index is currently in widespread use. Thus, we aimed to construct and validate a simple ultrasound score for Crohn's disease.

METHODS

Forty patients were prospectively examined with ultrasound and endoscopy in the development phase. The Simple Endoscopic Score for Crohn's Disease [SES-CD] was used as a reference standard. Seven ultrasound variables [bowel wall thickness, length, colour Doppler, stenosis, fistula, stratification and fatty wrapping] were initially included, and multiple linear regression was used to select the variables that should be included in the final score. Second, the ultrasound data from each patient were re-examined for interobserver assessment using weighted kappa and intraclass correlation. Finally, the activity index was validated in a new cohort of 124 patients.

RESULTS

Length, fistula and stenosis were excluded. The combination of the remaining variables provided a multiple correlation coefficient of r = 0.78. Interobserver analysis revealed poor agreement for stratification and fatty wrapping and these were thus excluded. There was excellent interobserver agreement for the remaining score consisting of wall thickness and colour Doppler. In both patient cohorts, the ultrasound score correlated well with SES-CD [Development cohort: rho = 0.83, p < 0.001, Validation cohort: rho = 0.78, p < 0.001]. A receiver operating characteristic curve analysis revealed an area under the curve of 0.92 and 0.88 for detecting endoscopic activity and moderate endoscopic activity, respectively.

CONCLUSIONS

A simple ultrasound activity index for Crohn's disease consisting of bowel wall thickness and colour Doppler was constructed and validated and correlated well with endoscopic disease activity.ClinicalTrials. gov ID: NCT03481751.

Use of Cross-Sectional Imaging for Tight Monitoring of Inflammatory Bowel Diseases

A treat-to-target strategy with close monitoring of intestinal inflammation is recommended in inflammatory bowel disease (IBD). Ileocolonoscopy remains the gold standard for assessing disease activity in IBD but is a relatively invasive procedure and is impossible to repeat in the context of tight monitoring strategies. In addition to biomarkers, cross-sectional imaging increasingly is used in these patients. Computed tomography is limited by the use of radiation, while the use of magnetic resonance enterography (MRE) is limited by its cost and access. There is growing interest in bowel ultrasound that represents a cost-effective, noninvasive, and well-tolerated modality in clinical practice, but it is operator dependent. Compared with ileocolonoscopy and MRE, bowel US has been shown to have the same level of accuracy in assessing and monitoring disease activity for both CD and UC and thus can be considered a point-of-care test. Diffusion-weighted imaging (DWI) is a MR imaging technique that increasingly is used in both IBD and non-IBD conditions and has been shown to be a valuable and accurate tool for assessing and monitoring IBD activity. Compared with conventional MRE, DWI is quicker, less time consuming, may not require intravenous contrast agent, fasting, bowel cleansing, oral preparation, or rectal preparation. This review discusses the role of these cross-sectional imaging techniques for the management of patients with IBD. In the near future, the value of DWI and ultrasound in assessing IBD will require further investigation in the era of transmural healing in CD and complete mucosal healing, including histologic remission, in ulcerative colitis.

Usefulness of magnetic resonance enterography in the clinical decision-making process for patients with inflammatory bowel disease

OBJECTIVE

To evaluate the impact of magnetic resonance enterography (MRE) diagnosis on clinical decision-making regarding treatment choice and maintenance of treatment over time in patients with inflammatory bowel disease (IBD).

METHODS

A cohort of patients who underwent MRE for IBD assessment between 2011 and 2014 was analyzed. From clinical records, we retrospectively retrieved their demographic data and clinical data on their IBD at the time of MRE, the results of MRE and the patient's clinical course. Medical management decisions made during the three months following MRE and at the 15-month follow-up were assessed.

RESULTS

In total, 474 MREs were reviewed. In the first three-month period, MRE results led to changes in the medical management of 266 patients (56.1%). Of those, maintenance therapy was altered in 140 patients (68.3%) (90.7% step-up and 9.3% top-down strategy), 65 (24.4%) were prescribed a course of steroids and 61 (22.9%) underwent surgery. MRE confirmed a CD diagnosis in 14/41 patients (34.1%) previously diagnosed with indeterminate colitis or ulcerative colitis and in 4/18 patients (22.2%) with suspected IBD. At the 15-month follow-up, treatment remained unchanged in 289 patients (65.8%).

CONCLUSIONS

These results suggest that MRE is a diagnostic tool that provides valid information for the clinical-decision making process for patients with CD.

Evaluating inflammatory activity in Crohn's disease by cross-sectional imaging techniques

The evaluation of inflammatory bowel activity in patients with Crohn’s disease has traditionally been a challenge, mainly because of the difficulty in gaining endoscopic access to the small bowel. Historically, barium-based contrast studies were the only option for the evaluation of inflammatory activity in Crohn’s disease. They were gradually replaced by cross-sectional imaging techniques, computed tomography enterography (CTE) and magnetic resonance enterography (MRE) now being the modalities of choice for such evaluations. Those two imaging methods have provided important information regarding intestinal wall involvement and extra-intestinal manifestations of Crohn’s disease, not only assessing lesion characteristics and complications but also quantifying inflammatory bowel activity. The objective of this article is to review the main technical aspects of CTE and MRE, together with their indications, contraindications, and limitations, as well as the CTE and MRE imaging characteristics of inflammatory activity in Crohn’s disease.

Approach to the Patient with Axial Spondyloarthritis and Suspected Inflammatory Bowel Disease

To adequately and efficiently evaluate patients with gastrointestinal symptoms in the context of axial spondyloarthritis can be difficult, considering that many of these patients suffer from chronic pain, present high inflammatory parameters, and use drugs with possible gastrointestinal adverse effects. In addition, the immunosuppressive treatments that these patients can receive make it necessary to always consider infections within the differential diagnoses of inflammatory bowel disease. In this article, we propose a practical approach to patients diagnosed with axial spondyloarthritis and suspected inflammatory bowel disease.