MRI scoring system including dynamic motility evaluation in assessing the activity of Crohn's disease of the terminal ileum.

RATIONALE AND OBJECTIVES: We sought to investigate the value of a MRI scoring system including dynamic motility evaluation in the assessment of small bowel Crohn's disease activity. MATERIALS AND METHODS: From March 2005 to December 2006, 52 patients with suspected Crohn's disease onset or relapse underwent MRI on a 1.5-T magnet. Bowel distention was achieved orally assuming a mean of 1.6 L of a polyethyleneglycol (PEG) preparation. Per-patient assessment of disease activity was based on a scoring system including evaluation of morphology and motility of the small bowel and perivisceral structures (true-FISP, cine-true-FISP, and HASTE T2W sequences) and dynamic assessment of parietal contrast enhancement (FLASH T1W sequence). Patients were included in three categories, using endoscopic biopsy as the standard reference: no activity/quiescent disease, mild activity, or moderate-to-severe activity. Patients without terminal ileum involvement were excluded from data analysis. RESULTS: MRI allowed a detailed and panoramic evaluation of the small bowel in all subjects examined. MRI properly assessed 14 of 16 (87.5%) cases of no activity/quiescent disease, 12 of 14 (85.7%) cases of mild activity, and 15 of 15 (100%) cases of severe activity. Overall, activity score led to a per-patient misdiagnosis of disease activity in a nonsignificant proportion of subjects (4 of 45; 8.8%) (P > .05), determining two false-positive and two false-negative results of mild disease activity. Sensitivity, specificity, PPV, NPV, and overall accuracy in assessing disease activity were 93.1%, 87.5%, 93.1%, 87.5%, and 91.1%, respectively. CONCLUSION: Accurate assessment of Crohn's disease activity is achieved by using an activity score providing an overall interpretation of MRI findings.