Evaluation of bowel wall flow by color Doppler ultrasound in the assessment of inflammatory bowel disease activity in pediatric patients.

Objective: To assess inflammatory bowel disease (IBD) activity with Doppler ultrasound in pediatric patients, comparing the accuracy of the ultrasound findings with that of the concentrations of fecal calprotectin (FC).

Materials And Methods: In a consecutive series, we evaluated 53 examinations of 44 pediatric patients seen between 2014 and 2020: 28 with Crohn's disease, 15 with ulcerative colitis, and one with IBD unclassified. The diagnosis of IBD was made in accordance with the Porto criteria. The alteration studied in the greatest detail was bowel wall flow, which was classified by the lead investigator and two pediatric radiologists, all of whom were blinded to the FC concentrations and the other ultrasound findings. Bowel wall flow was categorized as low if there were up to 2 Doppler ultrasound signals/cm, moderate if there were 3-5 signals/cm, and high if there were more than 5 signals/cm.

Results: The agreement among the radiologists was substantial (kappa = 0.73). In cases in which ultrasound showed low bowel wall flow, the median FC concentration was 92 µg/g (interquartile range, 33-661 µg/g), whereas it was 2,286 µg/g (interquartile range, 1,728-5,612 µg/g) in those in which ultrasound showed high bowel wall flow. In the sample as a whole, the sensitivity and specificity of ultrasound was 89.7% and 92.0%, respectively, for the detection of inflammatory activity; 95.5% and 90.9%, respectively, for the detection of Crohn's disease; and 81.3% and 100.0%, respectively, for the detection of ulcerative colitis.

Conclusion: Ultrasound of the bowel wall showed a strong correlation with FC concentrations in the assessment of inflammatory activity in pediatric patients with IBD.