Can Contrast-Enhanced Sonography Detect Bowel Wall Fibrosis in Mixed Inflammatory and Fibrotic Crohn Disease Lesions in an Animal Model?

Diagnostic Value of Quantitative Contrast-Enhanced Ultrasound in Comparison to Endoscopy in Children With Crohn's Disease

OBJECTIVE

Quantitative contrast-enhanced US (CEUS) provides objective evaluation of bowel wall perfusion and has been reported as a useful method for evaluating Crohn's disease (CD) activity in children. We tested its' diagnostic accuracy in comparison to endoscopy and evaluated its' usefulness in comparison to Pediatric Crohn's Disease Activity Index (PCDAI) and fecal Calprotectin (FC).

MATERIALS AND METHODS

Children with CD and thickened bowel wall on abdominal US were prospectively enrolled. Disease activity was evaluated with quantitative CEUS, PCDAI and FC and compared to a simple endoscopic score for Crohn's disease (SES-CD). Spearman's correlation and Cohen's kappa statistic between the SES-CD and other disease activity measures were performed and diagnostic accuracies calculated.

RESULTS

36 children 3.5-18 years old (mean age 14 years) were included. The quantitative CEUS had 78.57% sensitivity (95%CI 0.59-0.92), 100% specificity (95%CI 0.63-1.0) and 83.33% diagnostic accuracy (95% CI 0.67-0.94). The concordance remission agreement with endoscopy was substantial for quantitative CEUS and PCDAI (quantitative CEUS: κ = 0.62; 95% CI 0.363-0.877; PCDAI: κ = 0.615; 95% CI 0.311-0.920), but only fair for FC (κ = 0.389; 95% CI 0.006-0.783). Correlation between all measures and endoscopy was moderate and statistically significant (quantitative CEUS: r_s  = 0.535, PCDAI: r_s  = 0.543, FC: r_s  = 0.497).

CONCLUSIONS

Quantitative CEUS has a potential of becoming a complementary method for evaluation of CD activity in children due to its' high specificity in comparison to endoscopy. Lower sensitivity makes it deficient as a single measure and further management should be guided by PCDAI and FC results as well.

Contrast-enhanced ultrasonography in the evaluation of Crohn disease activity in children: comparison with histopathology

BACKGROUND

Contrast-enhanced ultrasound (US) of the bowel wall has been suggested as an alternative imaging modality for the follow-up of children with Crohn disease.

OBJECTIVE

To evaluate the diagnostic performance of contrast-enhanced US in the estimation of Crohn disease activity in children with histopathology as the reference standard.

MATERIALS AND METHODS

In 24 children with Crohn disease confirmed on histopathology, disease activity was evaluated on 40 bowel segments using US score and subjective and quantitative contrast-enhanced US evaluation. Contrast-enhanced US evaluation included enhancement pattern analysis with a graphic representation of log time-intensity curve and calculation of kinetic parameters with the definition of thresholds for disease activity, as determined by receiver operating characteristics curve analysis. The diagnostic accuracy of US with colour Doppler imaging and subjective and quantitative contrast-enhanced US were calculated.

RESULTS

Moderate or severe inflammation was identified in 18 segments and remission or mild inflammation was identified in 22 segments on histopathology. The quantitative contrast-enhanced US, namely the peak enhancement value, had 72.2% sensitivity (95% confidence interval [CI] 46.5-90.3), 100% specificity (95% CI 84.6-100.0) and 87.5% diagnostic accuracy (95% CI 73.2-95.8) in predicting moderate or severe grade inflammation at histopathology. The sensitivity, specificity and diagnostic accuracy of subjective contrast-enhanced US were 77.8% (95% CI 52.4-93.6), 77.3% (95% CI 54.6-92.2) and 77.5% (95% CI 61.6-89.2), respectively, and of US with colour Doppler imaging were 55.6% (95% CI 30.8-78.5), 86.4% (95% CI 65.1-79.1) and 72.5% (95% CI 56.1-85.4), respectively.

CONCLUSION

Quantitative contrast-enhanced US has the potential of becoming a complementary method in the evaluation of Crohn disease activity in children. Fibrosis may affect peak enhancement results and underestimate inflammatory activity.

Contrast-enhanced ultrasound of the pediatric bowel

Contrast-enhanced ultrasound (CEUS) has emerged as a valuable modality for bowel imaging in adults and children. CEUS enables visualization of the perfusion of the bowel wall and of the associated mesentery in healthy and disease states. In addition, CEUS images can be used to make quantitative measurements of contrast kinetics, allowing for objective assessment of bowel wall enhancement. Bowel CEUS is commonly applied to evaluate inflammatory bowel disease and to monitor treatment response. It has also been applied to evaluate necrotizing enterocolitis, intussusception, appendicitis and epiploic appendagitis, although experience with these applications is more limited. In this review article, we present the current experience using CEUS to evaluate the pediatric bowel with emphasis on inflammatory bowel disease, extrapolating the established experience from adult studies. We also discuss emerging applications of CEUS as an adjunct or problem-solving tool for evaluating bowel perfusion.

Cross-sectional imaging for assessing intestinal fibrosis in Crohn's disease

More than 30% of patients with Crohn's disease (CD) develop fibrotic strictures in the bowel as the disease progresses. Excessive deposition of extracellular matrix components in the submucosa and smooth muscle hypertrophy or hyperplasia are the main features of fibrosis in CD. Cross-sectional imaging technology provides a wealth of information on the anatomy, histological composition, and physiological function of the bowel, allowing for a non-invasive and complete evaluation of associated abnormalities. This review summarizes recent advances in and the potential technologies of cross-sectional imaging for assessing intestinal fibrosis in CD, including ultrasound imaging, computed tomography, and magnetic resonance imaging.

Correlation between ultrasound consolidated score and simple endoscopic score for determining the activity of Crohn's disease

OBJECTIVES

The aim of this study was to develop an ultrasound consolidated score (UCS) in determining the activity of Crohn's disease (CD) and evaluate it with reference to simple endoscopic score (SES).

METHODS

From June 2014 to June 2017, 66 patients with CD were retrospectively enrolled in this study. Each patient underwent endoscopy and transabdominal ultrasound (US) examination. The morphological symmetry, echogenicity of bowel wall, bowel wall layer structure, echogenicity of peri-bowel fat, bowel wall thickness (BWT), and Limberg type on power Doppler US were assessed with transabdominal US, and an UCS scoring system was developed based on these characteristics. Endoscopic results were used as the reference standard and SES was calculated to determine the CD activity. Receiver operating characteristic curve analysis was performed to assess the diagnostic performance for determining CD activity and the correlation between UCS and SES was assessed using Spearman correlation analysis.

RESULTS

330 intestinal segments in 66 patients were included. The UCS of the segments in the remission phase ranged from 3.0 to 9.0 (mean, 3.6 ± 0.9) whereas in the active phase from 3.0 to 20.0 (mean, 10.6 ± 4.0) (p < 0.001). The cut-off value of UCS was 6. The associated area under ROC curve, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 0.980, 88.3%, 95.5%, 93.8%, 91.3%, and 92.3%, respectively. The correlation coefficient between UCS and SES was 0.90, which was higher than the correlation coefficient of 0.83 between BWT and SES.

CONCLUSIONS

The newly developed UCS with transabdominal US has a good performance and potentially provides an effective alternative for evaluating the activity of CD.

ADVANCES IN KNOWLEDGE

UCS is an effective method to evaluate the activity of CD because it provides comprehensive information of the disease. Therefore, it could be employed as an alternative for diagnosis of CD.

European Society of Paediatric Radiology abdominal imaging task force: statement on imaging in very early onset inflammatory bowel disease

Very early onset inflammatory bowel disease (VEO-IBD) is defined as disease presenting before the age of 6. These children require a tailored imaging approach because conventional imaging studies can be difficult to perform at such a young age. Unlike inflammatory bowel disease in older children and adults, colonic disease predominates in VEO-IBD, and small-bowel disease is rare. Distinguishing Crohn disease from ulcerative colitis is challenging both clinically and on histology. Radiology offers the greatest utility for detecting small-bowel disease because it helps to distinguish the two main disease entities and guide clinical management. Small-bowel ultrasound is recommended as the first-line investigation because it requires relatively little preparation, is readily available and is generally well tolerated in young children. We present these recommendations, based on the current evidence for radiologic management in this group, and propose an imaging algorithm for investigating VEO-IBD.

Contrast-Enhanced Ultrasound and Shear Wave Elastography Evaluation of Crohn's Disease Activity in Three Adolescent Patients

Characterizing inflammation and fibrosis in Crohn's disease (CD) is necessary to guide clinical management, but distinguishing the two remains challenging. Novel ultrasound (US) techniques: contrast-enhanced US (CEUS) and shear wave elastography (SWE) offer great potential in evaluating disease activity in pediatric patients. Three patients ages 16 to 20 with known CD underwent CEUS and SWE to characterize bowel wall inflammation and fibrosis. Magnetic resonance enterography, endoscopy, or surgical pathology findings are also described when available. The patients' disease activity included acute inflammation, chronic inflammation with stricture formation, and a fibrotic surgical anastomosis without inflammation. CEUS was useful in determining the degree of inflammation, and SWE identified bowel wall fibrosis. Used together these techniques allow for better characterization of the degree of fibrosis and inflammation in bowel strictures. With further validation CEUS and SWE may allow for improved characterization of bowel strictures and disease flares in pediatric patients suffering from CD.