Contrast enhanced ultrasound: comparing a novel modality to MRI to assess for bowel disease in pediatric Crohn's patients

Background: To demonstrate the feasibility and reliability of a novel imaging modality, contrast enhanced ultrasound (CEUS), in evaluating for distal small bowel inflammation in pediatric Crohn's disease (CD), and compare this to concurrently obtained magnetic resonance imaging (MRI) findings. Methods: Pediatric patients diagnosed with or having suspicion of CD with small bowel involvement, whose disease merited imaging with an MRI, concurrently underwent imaging with CEUS. We assessed the ability of CEUS to demonstrate distal small bowel disease by evaluating wall thickness, enhancement pattern, mucosal disruption and pericolonic inflammation. Concordance between imaging modalities was then assessed. Results: Twenty patients were recruited for the study, 16 with known CD, 3 with concern for CD, and one with known colitis, but unknown bowel disease status. Six patients (3 with prior diagnosis of CD, 3 without) had absence of bowel enhancement on both ultrasound and MRI. Eleven patients with findings of inflammation and enhancement on MRI also had concurrent evidence of enhancement on CEUS. Three patients who had no evidence of inflammation on MRI, with known CD, had prominent bowel enhancement on CEUS. One patient with known colitis, whom we enrolled to evaluate for small bowel disease, had no evidence on either MRI or CEUS, however CEUS showed significant fat stranding around the colon, supporting the diagnosis of CD. Conclusions: The sensitivity of CEUS to detect bowel inflammation when seen on MRI was 100%. In addition, CEUS may also have the ability to detect bowel inflammation, even in the presence of a normal MRI.