Use of magnetic resonance index of activity (MaRIA) in the preoperative assessment of small bowel Crohn's disease

Abstract

Background: Accurate quantification of the inflammatory activity in Crohn's Disease is essential to determine adequate treatment for each patient. The aim of the present study is to assess the correlation between the pre-operative Magnetic Resonance Index of Activity (MaRIA) and the histologic degree of inflammation from surgically resected intestinal Crohn's Disease lesions.

Methods: This is a prospective study including a consecutive case series of patients with small bowel Crohn's Disease, who underwent surgical resection. Magnetic resonance enterography was performed in the 3months prior to surgery, applying a pre-established protocol. Relative contrast enhancements, wall thickness, presence of edema or ulcerations were the parameters used to calculate the MaRIA Index. All patients underwent surgery and every specimen was analyzed. The modified Chiorean classification was applied for the histological analysis and an ordinal regression analysis was used to correlate MaRIA and the grade of inflammation for each lesion.

Results: 59 lesions from 35 different patients were analyzed. The degree of inflammation of the lesions was statistically correlated to the MaRIA values (P=.002). The MaRIA index was significantly different (P<.001) between the different histological types of the Crohn's Disease lesions (inflammatory/ fibrotic). The best cut-off for detecting severe inflammation using MaRIA was 20 (AUC: 0.741; 74.1% sensitivity and 78.1% specificity).

Conclusion: MaRIA is a reliable tool to distinguish inflammatory from fibrotic lesions. Therefore, it could be considered essential for determining the most appropriate Crohn's Disease treatment for each patient.

Keywords: Crohn's disease; Enfermedad de Crohn; MaRIA score; Magnetic resonance imaging; Preoperative assessment; Resonancia magnética; Valoración preoperatoria; Índice MaRIA.