Comparison of diagnostic accuracy and impact of magnetic resonance imaging and colonoscopy for the management of Crohn's disease

Abstract

Aims: The objective of the current study was to compare two patient assessment strategies using colonoscopy and MRI alternatively as first- and second-line examinations. Methods: Clinical data, endoscopy and magnetic resonance imaging (MRI) examinations of 100 patients diagnosed with ileocolonic Crohn's disease (CD) performed within 1 week were blindly reviewed by 4 clinical investigators. Two investigators evaluated MRI followed by colonoscopy for 50 cases and the same examinations in reverse order for another 50 cases; the other 2 investigators evaluated the same cases switching the order of examinations. The assessments included the likelihood of the presence of inflammation, stenosis, fistula and abscess, and therapeutic recommendations. Results: Information from the first examination was considered sufficient for management in 80% of cases for MRI and only 34% of cases for colonoscopy (p < 0.001). Adding MRI to the information from colonoscopy changed the clinicians' confidence grade in a higher proportion of patients than adding colonoscopy to information from MRI for the diagnosis of disease activity (10 vs 4%, p = 0.03), stenosis (25 vs 9%, p < 0.001), fistula (31 vs 0%, p < 0.001) and internal abscess (27 vs 0%, p < 0.001). Indications for anti-tumour necrosis factor (TNF) therapy (51 vs 37%, F = 0.006), and surgery (12 vs 5%, F = 0.019) were more frequent after MRI than after colonoscopy as first examination. As a second examination, MRI led to change in therapy in a higher proportion of patients than colonoscopy (28 vs 8%, p < 0.001). Conclusions: In CD, information provided by MRI has a higher impact on patient management than colonoscopy and may be considered as a first-line examination for CD assessment.