Ultrasonographic scores for ileal Crohn's disease assessment: Better, worse or the same as contrast-enhanced ultrasound?

Novelties and Perspectives of Intestinal Ultrasound in the Personalised Management of Patients with Inflammatory Bowel Diseases-A Systematic Review

Inflammatory bowel diseases (IBDs) affect over 4.9 million individuals worldwide. Colonoscopy (CS) is the gold-standard technique for diagnosis. The remissive-recurrent pattern of evolution raises the need for non-invasive techniques to monitor disease activity. This review aims to present the advantages of intestinal ultrasound (IUS) in managing IBDs. Our search was conducted on the PubMed, Embase, and Cochrane (CENTRAL) databases, selecting original studies comparing IUS with other imaging and invasive monitoring methods. Our search yielded 8654 results, of which 107 met the inclusion criteria. Increased bowel wall thickness (BWT) and colour Doppler signal (CDS) are discriminative for disease activity. IUS can predict disease outcomes and detect response to treatment or postoperative recurrence. Contrast-enhanced ultrasound (CEUS) and elastography help differentiate fibrotic from inflammatory stenoses. The difficult rectal assessment limits the use of IUS in ulcerative colitis (UC). Transmural healing may develop as a therapeutic target as it is associated with better outcomes. Patients are compliant with this technique, and its results correlate well with CS and other imaging methods. In conclusion, IUS proves to be essential in assessing IBD activity and treatment response, predicting outcomes and detecting complications. CEUS and elastography are researched to improve the diagnostic values of IUS.

Current Developments and Role of Intestinal Ultrasound including the Advent of AI

Intestinal ultrasound is a non-invasive, safe, and cost-effective technique to study the small and large intestines. In addition to conventional B-mode and color doppler imaging, new US tools have been developed in more recent years that provide auxiliary data on many GI conditions, improving the diagnosis and assessment of relevant outcomes. We have reviewed the more recent literature (from 2010 onwards) on auxiliary tools in bowel ultrasound such as elastography techniques, CEUS, SICUS, and the potential contribution by artificial intelligence (AI) to overcome current intestinal ultrasound limitations. For this scoping review, we performed an extensive literature search on PubMed and EMBASE to identify studies published until December 2023 and investigating the application of elastography techniques, CEUS, SICUS, and AI in the ultrasonographic assessment of the small and large intestines. Multiparametric intestinal ultrasound shows promising capabilities in Crohn's disease, while less is known about the role in ulcerative colitis. Despite some evidence, the CEUS role as a point-of-care examination tool for rare conditions such as intestinal GvHD and ischemic small bowel disease seems promising, possibly avoiding the need to perform further cross-sectional imaging. The use of AI in intestinal ultrasound is still anecdotical and limited to acute appendicitis.

EFSUMB Technical Review - Update 2023: Dynamic Contrast-Enhanced Ultrasound (DCE-CEUS) for the Quantification of Tumor Perfusion

Dynamic contrast-enhanced ultrasound (DCE-US) is a technique to quantify tissue perfusion based on phase-specific enhancement after the injection of microbubble contrast agents for diagnostic ultrasound. The guidelines of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) published in 2004 and updated in 2008, 2011, and 2020 focused on the use of contrast-enhanced ultrasound (CEUS), including essential technical requirements, training, investigational procedures and steps, guidance regarding image interpretation, established and recommended clinical indications, and safety considerations. However, the quantification of phase-specific enhancement patterns acquired with ultrasound contrast agents (UCAs) is not discussed here. The purpose of this EFSUMB Technical Review is to further establish a basis for the standardization of DCE-US focusing on treatment monitoring in oncology. It provides some recommendations and descriptions as to how to quantify dynamic ultrasound contrast enhancement, and technical explanations for the analysis of time-intensity curves (TICs). This update of the 2012 EFSUMB introduction to DCE-US includes clinical aspects for data collection, analysis, and interpretation that have emerged from recent studies. The current study not only aims to support future work in this research field but also to facilitate a transition to clinical routine use of DCE-US.

Diagnostic performance of sonographic activity scores for adult terminal ileal Crohn's disease compared to magnetic resonance and histological reference standards: experience from the METRIC trial

OBJECTIVES

The simple ultrasound activity score for Crohn's disease (SUS-CD) and bowel ultrasound score (BUSS) are promising intestinal ultrasound (IUS) indices of CD, but studied mainly in small settings with few sonographers. We compared SUS-CD and BUSS against histological and magnetic resonance enterography (MRE) reference standards in a post hoc analysis of a prospective multicentre, multireader trial.

METHODS

Participants recruited to the METRIC trial (ISRCTN03982913) were studied, including those with available terminal ileal (TI) biopsies. Sensitivity and specificity of SUS-CD and BUSS for TI CD activity were calculated with 95% confidence intervals (CI), from the prospective observations of the original METRIC trial sonographers against the histological activity index (HAI) and the simplified magnetic resonance index of activity (sMARIA).

RESULTS

We included 284 patients (median 31.5 years, IQR 23-46) from 8 centres, who underwent IUS and MRE. Of these, 111 patients had available terminal ileal biopsies with HAI scoring. Against histology, sensitivity and specificity for active disease were 79% (95% CI 69-86%) and 50% (31-69%) for SUS-CD, and 66% (56-75%) and 68% (47-84%) for BUSS, respectively. Compared to sMARIA, the sensitivity and specificity for active CD were 81% (74-86%) and 75% (66-83%) for SUS-CD, and 68% (61-74%) and 85% (76-91%) for BUSS, respectively. The sensitivity of SUS-CD was significantly greater than that of BUSS against HAI and sMARIA (p < 0.001), but its specificity was significantly lower than of BUSS against the MRE reference standard (p = 0.003).

CONCLUSIONS

Particularly when compared to MRE activity scoring, SUS-CD and BUSS are promising tools in a real-world clinical setting.

CLINICAL RELEVANCE STATEMENT

When tested using data from a multicentre, multireader diagnostic accuracy trial, the simple ultrasound activity score for Crohn's disease (SUS-CD) and bowel ultrasound score (BUSS) were clinically viable intestinal ultrasound indices that were reasonably sensitive and specific for terminal ileal Crohn's disease, especially when compared to a magnetic resonance reference standard.

KEY POINTS

The simple ultrasound activity score for Crohn's disease and bowel ultrasound score are promising intestinal ultrasound indices of Crohn's disease but to date studied mainly in small settings with few sonographers. Compared to histology and the magnetic resonance reference standard in a multicentre, multireader setting, the sensitivity of simple ultrasound activity score for Crohn's disease is significantly greater than that of bowel ultrasound score. The specificity of simple ultrasound activity score for Crohn's disease was significantly lower than that of bowel ultrasound score compared to the magnetic resonance enterography reference standard. The specificity of both indices was numerically higher when the magnetic resonance enterography reference standard was adopted.

Intestinal ultrasound score predicts therapeutic outcomes of infliximab in pediatric patients with Crohn's disease

BACKGROUND AND AIMS

Objective evaluation of treatment response is critical in the management of Crohn's disease (CD). Compared with endoscopy, intestinal ultrasound (IUS) is non-invasive and well-tolerated. This study is aimed to assess the predictive value of IUS score for treatment response in pediatric CD patients.

METHODS

We conducted a retrospective study in pediatric CD patients who underwent endoscopy and IUS at start of infliximab treatment [T0] and after 22-38 weeks [T1] between February 2021 and January 2023. Pediatric Crohn's Disease Activity Index (PCDAI), biochemical parameters, the Simple Endoscopic Score for Crohn's disease (SES-CD) and IUS parameters were collected at two timepoints. IUS scores were assessed by International Bowel Ultrasound Segment Activity Score (IBUS-SAS).

RESULTS

Thirty patients were included, with 53.3% reaching endoscopic response and 43.3% endoscopic remission. After infliximab treatment, IBUS-SAS (58.5 ± 24.2 vs 34.4 ± 21.6, p = .0001) was significantly decreased. At T1, change in IBUS-SAS (-38.2 ± 22.0 vs -7.9 ± 24.1, p = .0015) were pronounced in patients with endoscopic response compared with endoscopic non-response. Significant correlation were observed between IBUS-SAS and SES-CD, PCDAI, C-reaction protein, erythrocyte sedimentation rate, hemoglobin, albumin. The most accurate cutoff values for predicting endoscopic response were 57.4% decrease of IBUS-SAS (AUROC: 0.862, p < .001). The optimal cut-off of IBUS-SAS to correlate endoscopic remission was 26.0 (AUROC: 0.686, p = .017).

CONCLUSIONS

The validated ultrasound-base score, IBUS-SAS is an effective index for monitoring endoscopic response to infliximab therapy in CD. IUS evaluation could guide treatment decision for pediatric CD.

Intestinal Ultrasound Combined with Blood Inflammatory Markers Is a More Efficient Tool in Evaluating Severity of Crohn's Disease: A Pilot Study

Background and Aims

Intestinal ultrasound (IUS) is considered a nonirradiating, noninvasive, well-tolerated, and valuable tool for objectively assessing Crohn's disease (CD) activity. However, there is no widely accepted intestinal ultrasound scoring system. This study is aimed at evaluating the efficacy of IUS key parameters, the International Bowel Ultrasound Activity Score (IBUS-SAS), and IBUS-SAS combined with blood inflammatory markers in assessing CD activity.

Methods

40 CD patients were reviewed in this retrospective study and were divided into the moderate-severe group (n = 25) and nonmoderate-severe group (n = 15) based on a simplified endoscopic score of Crohn's disease (SES-CD). Double-balloon enteroscopy/colonoscopy were reviewed by three gastroenterologists. A transabdominal ultrasound was performed by two ultrasound specialists. Blood inflammatory markers were measured from morning samples.

Results

In evaluating moderate to severe CD patients, (1) IBUS-SAS had a good predictive effect with an area-under-the-curve (AUC) of 0.855 (P < 0.001); (2) IUS key parameters (including BWT, CDS, BWS, and I-fat) yielded good predictive effects with AUC of 0.811, 0.731, 0.724, and 0.747, respectively (P < 0.001); (3) blood inflammatory markers (including ESR, CRP, PLR, MLR, and NLR) also had good predictive effects with AUC of 0.771, 0.837, 0.728, 0.743, and 0.775, respectively (P < 0.001); (4) IBUS-SAS combined with ESR and CRP exerted the best predictive effect with the highest AUC of 0.912 (95% CI: 0.823-1.000), and the sensitivity and specificity were 88.0% and 80.0%, respectively (P < 0.001).

Conclusion

IBUS-SAS combined with ESR and CRP is a more efficient tool than IBUS-SAS alone or inflammatory markers alone in evaluating CD patients with moderate to severe disease activity.

Correlation of Ultrasound Scores with Endoscopic Activity in Crohn's Disease: A Prospective Exploratory Study

BACKGROUND AND AIMS

Intestinal ultrasound [IUS] is widely accepted as a reliable tool to monitor Crohn's disease [CD]. Several IUS scores have been proposed, but none has been formally accepted by international organizations. Our aim here was to compare the available scores regarding their correlation with endoscopic activity.

METHODS

Consenting CD patients undergoing ileocolonoscopy at our Unit between September 2021 and February 2023 were included. Endoscopic activity was defined as SES-CD ≥ 3 or Rutgeerts score ≥ i2b for operated patients. IUS was performed within 6 weeks of endoscopy and scored with IBUS-SAS, BUSS, Simple-US and SUS-CD scores. All correlations were performed using Spearman's rank coefficient [rho = ρ]. Receiver operating characteristic [ROC] curves were compared with the Hanley and McNeil method.

RESULTS

Of 73 CD patients, 45 [61.6%] presented endoscopic activity, of whom 22 were severe [30.1%]. All IUS scores showed a significant positive correlation with endoscopy [p < 0.0001], with IBUS-SAS ranking the highest [ρ = 0.87]. Similarly, IBUS-SAS was the most highly correlated with clinical activity [ρ = 0.58]. ROC analysis of IBUS-SAS for any endoscopic activity showed the highest area under the curve (0.95 [95% confidence interval 0.87-0.99]), with sensitivity of 82.2% and specificity of 100% for a cut-off value of 25.2. IBUS-SAS was statistically superior to all the other scores in detecting severe endoscopic activity [SES-CD ≥ 9 or Rutgeerts i4].

CONCLUSIONS

All IUS scores provided solid correlation with endoscopy and clinical symptoms. IBUS-SAS outperformed the others due to a more granular description that might help in stratifying different levels of disease activity. Therefore, the use of IBUS-SAS in centres with well-founded expertise in IUS can be suggested.

Predicting Treatment Response in Inflammatory Bowel Diseases: Cross-Sectional Imaging Markers

Therapeutic options for inflammatory bowel diseases (IBD) have largely expanded in the last decades, both in Crohn's disease and ulcerative colitis, including multiple biological drugs targeting different inflammation pathways. However, choosing the best treatment and timing for each patient is still an undeniable challenge for IBD physicians due to the marked heterogeneity among patients and disease behavior. Therefore, early prediction of the response to biological drugs becomes of utmost importance, allowing prompt optimization of therapeutic strategies and thus paving the way towards precision medicine. In such a context, researchers have recently focused on cross-sectional imaging techniques (intestinal ultrasound, computed tomography, and magnetic resonance enterography) in order to identify predictive markers of response or non-response to biologic therapies. In this review, we aim to summarize data about imaging factors that may early predict disease behavior during biological treatment, potentially helping to define more precise and patient-tailored strategies.

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.

Comment on "Ultrasonographic scores for ileal Crohn's disease assessment: better, worse or the same as contrast‑enhanced ultrasound?"

We read with interest the study by Freitas et al. comparing contrast-enhanced ultrasound (CEUS) and parameters from a time-intensity curve (TIC) with the SUS-CD score and IBUS-SAS score in patients with Crohn's disease (CD) undergoing gastrointestinal ultrasound (GIUS) and ileocolonoscopy. The aim was to compare the accuracy of CEUS and aforementioned scores in predicting terminal ileal inflammatory activity in patients with CD. In this retrospective study of 50 patients, inflammatory activity was defined as a segmental score of SES-CD ≥ 7 in the terminal ileum. The study found 30 patients with active endoscopic disease demonstrating no significant difference between the "inactive" and "active" SUS CD and IBUS-SAS scores. However, the CEUS peak enhancement derived from the TIC was shown to be significantly different. The authors conclude CEUS was superior for detecting inflammation in the terminal ileum, as opposed to ultrasound scores relying on bowel wall thickness and color Doppler.

External validation and comparison of simple ultrasound activity score and international bowel ultrasound segmental activity score for Crohn's disease

BACKGROUND

Intestinal ultrasound (IUS) is a non-invasive tool for monitoring Crohn's disease (CD) activity. Recently, sonographic activity scores, including the International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) and Simple Ultrasound Activity Score for CD (SUS-CD), were developed. This study aimed to assess their clinical application value.

METHODS

This retrospective study enrolled patients with CD from March 2021 to June 2022. The diagnostic performance of the ultrasound scores was evaluated using the simplified endoscopic score for CD (SES-CD). Correlations of ultrasound scores with SES-CD, CD activity index (CDAI), and inflammatory biomarkers were assessed. Inter-rater reliability was compared.

RESULTS

In total, 140 patients were included. The IBUS-SAS for evaluating disease activity had an area under the curve (AUC) of 0.895, sensitivity of 85.4%, and specificity of 82.4% for the cut-off value of 48.7. The SUS-CD revealed an AUC of 0.835, sensitivity of 92.7%, and specificity of 64.7% for the cut-off value of 2.5. The IBUS-SAS and SUS-CD were positively correlated with SES-CD (r = 0.511 and 0.534, respectively). The scores correlated significantly with the CDAI and inflammatory biomarkers (all p < 0.01). The IBUS-SAS was more strongly correlated with CDAI (r = 0.666 vs 0.486) and C-reactive protein (r = 0.645 vs 0.434) than the SUS-CD. The intraclass correlation coefficient (ICC) of the IBUS-SAS and SUS-CD between the two sonologists was excellent (ICC = 0.96 and 0.78, respectively).

CONCLUSION

Both the IBUS-SAS and SUS-CD can evaluate disease activity in CD and exhibited a significant correlation with activity indices and inflammatory biomarkers.

CLINICAL TRIAL REGISTRATION

ChiCTR2200055221.