Background: CT (CTE) and MR (MRE) enterography have not compared in Crohn’s disease (CD) in Indian setting. Recently MRI severity index has been developed for objective assessment of inflammatory activity in CD.
Aim: To compare CTE with MRE in CD with respect to diagnostic yield and impact on management and evaluate the utility of MRI severity index in CD.
Methods: Records of 29 patients (median age 43 years, range 18 - 70 and standard deviation 15.36;15 female) with CD who underwent CTE and MRE using standard protocols were retrospectively analyzed. Inflammatory activity, stricture detection and costs were compared. The co-relation between clinical activity, biochemical markers (fecal calprotectin, serum C-reactive protein), and the MRI severity index was studied.
Results: Fourteen patients had clinically active disease, 15 were in clinical remission. In patients with active clinical disease, MRE identified 14 percent more cases with abnormal imaging findings compared to CTE. Small bowel involvement was detected in 5 patients on CTE, 10 on MRE (p=0.133). Ileocolonic involvement was seen in 15 patients on CTE and 19 on MRE (p=0.28). Stricture was detected in 2 patients on CTE and 9 on MRE (p=0.01). In 17 patients, clinical management was altered based on abnormal MRE findings, giving 58.6% absolute increased yield of MRE over CTE. There was significant correlation between MRI severity index and disease activity (r=0.70, p<0.0001) and fecal calprotectin (r=0.52; p<0.003), but not CRP (r=0.03; p<0.1). Average cost for CTE was Rupees 9214 (INR) and 12121 INR for MRE.
Conclusion: MRE was better than CTE in diagnosing stricture in CD. The MRI severity index correlated with clinical activity and fecal calprotectin.