Assessment of Crohn's disease activity by doppler ultrasound of superior mesenteric artery and mural arteries in thickened bowel wall: cross-sectional study.

AIM To define sensitive and reliable Doppler parameters for measurements in the superior mesenteric artery and mural arteries of affected bowel loops used in the assessment of Crohn disease activity. METHODS We performed cross-sectional study at a tertiary care setting in Zagreb, Croatia, between January 2001 and March 2005. We measured arterial flow in the superior mesenteric artery and affected bowel wall in 138 patients with Crohn disease (74 with active, 64 with inactive disease) and 67 healthy volunteers. The disease activity was determined by the clinical examination, Crohn disease activity index, and standard laboratory tests. Superior mesenteric artery color and pulsed Doppler parameters were peak systolic velocity, end-diastolic velocity, resistance index, mean velocity flow, cross-sectional area, and flow volume. When gut mural vessels were identified, we performed spectral analysis of mural arteries by pulsed Doppler, with a measurement of resistance index. RESULTS The measurements in the superior mesenteric artery showed statistically and clinically significant difference in flow volume in active group, compared with inactive and control groups (C+/-Q=564+/-263 mL/min for active, 421+/-157 for inactive and 416+/-248 for control group). Affected bowel loops analysis showed significant difference between inactive and active Crohn disease group in wall thickness (3.1+/-1.4 vs 5.0+/-1.8 mm, P<0.001, Mann-Whitney test) while all participants from control group had thickness below 2mm. Intensity of color Doppler signals was different for all groups (P<0.001, chi(2) test) with the highest level of hyperemia in the active group. Resistance index measurements of mural arteries in bowel wall revealed differences between all three groups (0.61+/-0.05 in active group, 0.71+/-0.05 in the inactive group and 0.80+/-0.11 in the control group, P<0.001, Kruskal-Wallis test). CONCLUSION Intensity of color Doppler signals and resistance index measurements of mural arteries in the thickened bowel wall can be used as quantitative diagnostic tool in the assessment of Crohn disease activity.