Evaluation of Crohn Disease Activity Using a Potential Abbreviated MRE Protocol Consisting of Balanced Steady-State Free Precession MRI Only Versus Full-Protocol MRE

OBJECTIVE. The purpose of the present study was to compare the diagnostic performance of an abbreviated MR enterography (MRE) protocol consisting of balanced steady-state free-precession (b-SSFP) imaging only versus standard full-protocol MRE for the evaluation of Crohn disease activity. MATERIALS AND METHODS. This single-center retrospective study included 112 patients with Crohn disease (66 women and 46 men; age range, 18-84 years) who underwent MRE between January 2017 and March 2018. Utilizing binary and 5-point Likert confidence scales, two blinded readers independently interpreted and scored disease activity on b-SSFP sequences only and on full-protocol MRE images. Interreader and intrareader agreement on confidence regarding disease activity were calculated using weighted kappa indexes. Correlation between MRE findings of Crohn disease and the Harvey-Bradshaw index was also performed. RESULTS. Perfect intrareader agreement and strong interreader agreement on disease activity were observed (intrareader agreement: kappa = 0.97, 0.96, and 0.96 for reader A, reader B, and both readers combined; interreader agreement: kappa = 0.82 for b-SSFP imaging only and kappa = 0.81 for MRE). For detecting active Crohn disease, b-SSFP sequences had a sensitivity and specificity of 97% and 100%, respectively, for reader A and 98% and 86%, respectively, for reader B. Strong-to-perfect intrareader agreement was achieved between b-SSFP imaging only and MRE for identification of penetrating disease (kappa = 0.80 and 0.97) and stenosing disease (kappa = 0.87 and 0.95). Perfect intrareader agreement was also obtained between b-SSFP imaging only and MRE for detecting abnormal bowel segments (kappa = 0.91 for reader A; kappa = 0.98 for reader B). Weak agreement was noted between both b-SSFP imaging only and MRE versus the Harvey-Bradshaw index ( kappa = 0.08 of reader A; kappa = 0.04 for reader B). CONCLUSION. Robust agreement was observed between b-SSFP imaging only and full-protocol MRE for the assessment of Crohn disease activity and complications. An abbreviated MRE protocol that exclusively uses b-SSFP sequences appears feasible and has significant implications for health care resources.