Assessment of activity of Crohn's disease by Doppler sonography of superior mesenteric artery flow.

BACKGROUND Evaluation of activity of Crohn's disease is based on CDAI. Several other tools have been studied to assess disease activity with more accuracy. AIMS To assess the correlation between Doppler parameters of superior mesenteric artery and disease activity and to assess the accuracy of these parameters in discriminating between active and quiescent Crohn's disease. MATERIAL AND METHODS We perform a prospective study including non-operated and non-complicated Crohn's disease patients involving terminal ileum and/or right colon and sex and age-matched controls. Doppler sonography of superior mesenteric artery was performed in all subjects. RESULTS We studied 41 patients and 15 controls. There was no statistical difference between patients and controls according to the studied US parameters. The difference in resistance index between the three groups using analysis of variance is not significant (p=0.064). Resistance index was significantly lower in patients with active disease compared to inactive disease patients (0.82 +/- 0.04 vs 0.85 +/- 0.03; p=0.01). Pulsatility index was also lower in patients with active disease compared to inactive disease patients (1.37 +/- 0.21 vs 1.53 +/- 0.15; p=0.01). A value of resistance index less than 0.79 predicted active disease with a sensitivity of 35.3% and specificity of 95.7%. A value of pulsatility index less than 1.56 predicted active disease with a sensitivity of 94.1% and specificity of 43.5%. In case of resistance index less than 0.79 and pulsatility index less than 1.56 in the same patient, the probability of active disease was 86%. However, in case of resistance index over than 0.79 and pulsatility index over than 1.56, this probability was only 9%. In Crohn's disease patients, correlation study showed that resistance index value was significantly correlated with CDAI (r=-0.46; p=0.003). Pulsatility index value was also correlated with CDAI (r=-0.39; p=0.01). CONCLUSION Doppler sonographic parameters of superior mesenteric artery are significantly correlated with disease activity in non-operated and non-complicated Crohn's disease.