Diagnostic accuracy of preoperative magnetic resonance in determination of the extension and inflammatory activity of small bowel Crohn's disease.

摘要

Introduction: The precise location and inflammatory activity assessment of Crohn's Disease intestinal lesions is of paramount importance for the treatment approach proposed for individual patients.;Methods: Prospective, observational and consecutive study. The Lennard-Jones criteria and the Montreal classification were used to diagnose and classify the patients. All patients underwent an MRI enterography exploration 3 months before surgery using the same imaging protocol and sequences. A thorough inspection and intraluminal sphere calibration of the entire small bowel was completed in each patient. Chiorean histological criteria were used to classify tissue samples.;Results: 38 patients with 83 small bowel lesions were included. MRI was found to have a 90% accuracy rate for locating intestinal lesions (Sensitivity 75% Specificity 95.7%). A fecal calprotectin of 185 microg is the cut-off point between moderate or severe inflammation. 8.6% of the lesions were detected only by the intraluminal sphere calibration having been overlooked during the macroscopic inspection. Dynamic MRI intensity curves had an 80.9% correlation with the histological analysis. MaRIA scores were significantly higher with more severe degrees of inflammation (p < 0.05).;Conclusions: Intraluminal calibration with spheres should always be done during the surgical act. The fecal calprotectin test is an excellent biological marker of inflammatory activity. The MaRIA score tends to overestimate inflammation in small bowel lesions (we propose the MaRIA-small with a cut-off point of 16 and 20 for moderate and severe inflammation respectively). Chiorean histological criteria should be reviewed, subclassifying mixed lesions in to mild and severe, due to their very different range of inflammatory activity. There is a high degree of correlation between the dynamic MRI intensity curves and the actual inflammatory activity in the tissue. The MRI is a helpful tool to distinguish inflammatory vs. fibrotic small bowel Crohn's Disease lesions and hence essential in the therapeutic decision.