Ressonância magnética de 3 tesla na avaliação da atividade inflamatória em pacientes com Doença de Crohn

Abstract

Background: The degree of inflammatory activity in transmural inflammation is largely unknown during Crohn’s disease (CD) therapy. Magnetic resonance imaging (MRI) has high sensitivity and specificity for the assessment of disease activity, but few studies have been performed using 3.0 Tesla (3T) MRI, which has become more widely available and could improve accuracy in grading disease activity. Methods: Retrospective study of 63 consecutive patients (49% female, median age 34 years) with CD who underwent 3T MR enterography. Patients were allocated into one of two categories, using the Crohn’s Disease Activity Index (CDAI) as the reference standard: no activity/quiescent disease or active disease. The frequency of 10 conventional MRI findings of actively inflamed bowel and changes typical of CD were evaluated by two radiologists blinded to clinical data. Analyses were performed using the paired t test and Wilcoxon ranktest. Results: Mean patient age in the active and quiescent disease groups was 35.0 ± 13.2 and 34.6 ± 10.3 years respectively (P = 0.9). Patients with active disease were more likely to have bowel wall enhancement (73% versus 44%, P = 0.03, sensitivity [Se]-73%, specificity [Sp]-56%, positive predictive value [PPV]-71%, negative predictive value [NPV]-58%), intramural edema (65% versus 28%, P = 0.007, Se-65%, Sp-72%, PPV-78%, NPV-58%), creeping fat (52% versus 16%, P = 0.008, Se-52%, Sp-84%, PPV-83%, NPV-53%), wall thickening > 3 mm (76% versus 44%, P = 0.01, Se-76%, Sp-56%, PPV-72%, NPV-60%), bowel stenosis (47% versus 12%, P = 0.008, Se-47%, Sp-88%, PPV-85%, NPV-52%), comb sign (39% versus 0%, P = 0.001, Se-39%, Sp-100%, PPV-100%, NPV-52%), and skip lesions (50% versus 12%, P = 0.005, Se-50%, Sp-88%, PPV-86%, NPV-53%). Conclusion: Magnetic resonance enterography at 3Tesla has high sensitivity for assessment of bowel wall thickening, edema, and enhancement. It is a feasible imaging modality for assessment of inflammatory activity in patients with Crohn’s disease.