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: kappa = 0.62; 95% CI 0.363-0.877; PCDAI: kappa = 0.615; 95% CI 0.311-0.920), but only fair for FC (kappa = 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.