MR enterography with polyethylene glycol as oral contrast medium in the follow-up of patients with Crohn disease: comparison with CT enterography.

Background: To compare magnetic resonance enterography (MRE) and computed tomography enterography (CTE) in detecting inflammatory bowel disease activity (IBD) in patients with Crohn's disease (CD).

Methods: A total of 29 patients (M 20; F 9; mean age 43.8 ± 15.9) with known CD underwent MRE. MRE was performed at 1.5 T using phased-array sense body coil, after oral administration of 1.5-2 L of PEG solution as oral contrast agent. MRE protocol included T1-weighted, sSShT2, sBTFE and gadolinium-enhanced THRIVE sequences acquired on coronal and axial planes. CTE was performed using a 16 multidetector-row computed-tomography before and after intravenous administration of 120 mL of iodinated contrast. MRE images and CTE scans were reviewed by a radiologist for bowel thickness and enhancement, mesenteric lymph nodes, vascular engorgement, fibrofatty proliferation, fistulas and abscesses. The disease activity was also defined by CDAI > 150.

Results: MRE has demonstrated a good sensitivity in detection of CD activity, particularly in depiction of mural thickening, mural enhancement, and vascular engorgement. The level of agreement between the two technique was excellent in evaluating wall thickening with mucosal hyperenhancement (κ = 1), comb (κ = 0.90) and halo signs (κ = 0.86). In detecting fibrofatty proliferation and mesenteric lymph nodes, CTE was superior to MRE (accuracy: P < 0.05), while MRE was superior in visualization of fistulas.

Conclusion: MRE is an accurate method in monitoring the activity of CD as compared to CTE and may be considered an alternative to CTE in assessing degree of CD and evaluating therapeutic effectiveness.