Mesenteric Transit Time Using Contrast-Enhanced Ultrasound (CEUS) Does Not Correlate with Disease Activity in Crohn's Disease

Purpose: Evaluation of mesenteric transit time (MU) - measured by contrast-enhanced ultrasound - as a marker for inflammatory activity in Crohn's disease. Materials and Methods: The time of maximum enhancement of the contrast agent in the superior mesenteric artery and vein was determined visually and by software analysis. The MIT was calculated as the difference between these two time points. Findings were correlated with the Harvey-Bradshaw Index (HBI) using the Pearson correlation coefficient (r). In addition, a healthy control group was evaluated both in the fasting state and 1, 2, 3 and 4 hours postprandially. Results: In 20 healthy controls the mean visual MU during fasting was 9.76 +/- 2.83 sec and decreased to a minimum 1 hour after the meal (6.6 +/- 2.27 sec). 45 patients with Crohn's disease (9 males, 36 females, mean age 35 years) had a mean HBI of 5.9 +/- 4.7 points. The mean software-based MIT of 9.76 +/- 3.7 sec was significantly higher (p=0.034) than the mean visual MU of 8.22 +/- 3.05 sec. The two figures correlated well (r=0.72, p < 0.001). The HBI correlated neither with the visual (r=0.14, p=0.371) nor with the software-based (r=0.16, p=0.293) MU. Conclusion: The MU decreases in the first two hours after eating. The visually assessed and the software-based MIT correlate well, however MU does not correlate with disease activity in patients with Crohn's disease.