Contrast-enhanced power Doppler of the intestinal wall in the evaluation of patients with Crohn disease

Background: Crohn disease (CD) manifests with highly variable signs and symptoms, and assessment of the status of the disease in the single patient can be difficult. This study was conducted to evaluate the efficacy of power colour Doppler ultrasonography, with and without echo-enhancement, in distinguishing active from quiescent CD. Methods: Resistance Index (RI) of the superior mesenteric artery (SMA), bowel thickness of the affected loops and the presence of colour signals at power Doppler analysis prior to and after ultrasonography contrast agent injection (Levovist®) were evaluated in 48 patients with CD. Results: In our series, 26 48 patients had active and 22 48 had quiescent CD. A CDAI score ≥150 and a pathological (>5 mg dL) C reactive protein were significantly correlated with active disease (P < 0.001 and P = 0.004, respectively). Intestinal wall thickness showed no significant correlation with disease status (7.5 ± 1.3 mm in active disease versus 6.8 ± 1.3 mm in quiescent disease; P = 0.11). Vascular signals in the affected loops were revealed in 11 22 patients (50%) with active disease and in 5 26 (20%) with quiescent disease (P = 0.052). After Levovist injection, colour signals were found in 22 22 with active and in 8 26 with quiescent CD (P < 0.001). SMA RI was significantly lower in active CD patients (0.81 ± 0.01 versus 0.83 ± 0.02; P = 0.001). Conclusions: Our data suggest that in patients with CD a finding of a SMA RI ≤ 0.81, or the presence of a colour signal in the wall of the affected loops, at power Doppler sonography, is indicative of active disease. Utilization of echo-enhancer media can greatly improve the diagnostic sensitivity of intestinal wall power Doppler scan. A finding of intestinal wall thickening is not associated with active disease in our series.