Crohn’s disease integrated imaging: MR-enterography vs CT-enterography

Purpose: to prospectively evaluate the diagnostic capabilities of Magnetic Resonance Imaging (MRI) and Multidetector Computed Tomography (MDCT) in Crohn’s disease (CD). Materials and Methods: 30 consecutive patients with known or suspected CD underwent MRI and MDCT of the small bowel. MR and CT examinations were performed after oral administration of polyethylene-glycol solution (1 litre and 2 litres respectively). MRI protocol included T2-weighted SSFSE, FIESTA and Gd-enhanced T1-weighted LAVA sequences. MDCT scans were acquired 60 seconds after i.v. administration of 110-130 ml non ionic iodinated contrast medium. MR and CT scans were evaluated by two radiologists blinded to the gold standard represented by conventional enteroclysis, endoscopy and histology findings available in all patients. Results: disease prevalence was 76.7%. MRI showed sensitivity of 91.3% (95% CI: 79.8%-102.8%), specificity of 85.7% (95% CI: 59.8%-111.6%), accuracy of 90%, predictive positive value (PPV) of 95.5%, predictive negative value (NPV) of 75%. MDCT showed sensitivity of 95.7% (95% CI 87.3%-104%), specificity of 85.7% (95% CI 59.8%-111.6%), accuracy of 93.3%, PPV of 95.7%, NPV of 85.7%. MRI and MDCT evaluated luminal, parietal and extraintestinal findings. MR-fluoroscopy provided functional information about intestinal distension and motility. Conclusion: MR and CT-enterography are complementary non-invasive imaging techniques that enable a complete assessment of CD. Lack of radiation exposure yields MRI the preferred method for the follow-up of patients with CD. Due to its widespread availability and short examination time MDCT is the imaging tool of choice in case of acute clinical presentation or if complications are suspected.