Utility of magnetic resonance imaging in Crohn's associated sacroiliitis:A cross-sectional study

OBJECTIVE: Prevalence of sacroiliitis in Crohn’s disease (CD) is variable depending on defining criteria. This study utilized standardized sacroiliac joint (SIJ) MRI to identify sacroiliitis in CD patients and its association with clinical and serological markers. METHODS: In this cross-sectional study, consecutive adult subjects with CD were prospectively enrolled from an inflammatory bowel disease clinic. All subjects underwent SIJ MRI. Data collected included CD duration, history of joint/back pain, HLA-B27 status, Bath Ankylosing Spondylitis Metrology Index (BASMI), Bath Ankylosing Spondylitis Disease Activity Index, Harvey-Bradshaw Index (HBI) for activity of CD, Ankylosing Spondylitis Disease Activity Score, C-reactive protein, and various serologic markers of inflammation. Three blinded readers reviewed MRIs for active and/or structural lesions according to the Spondyloarthritis Research Consortium of Canada modules. RESULTS: 33 CD patients were enrolled: 76% female, 80% white, median age 36.4 years (IQR 27.2–49.0), moderate CD activity (mean HBI 8.8±SD 4.5). 19 subjects (58%) reported any back pain, 13 of whom met ASAS inflammatory back pain criteria. 4 subjects (12%) showed sacroiliitis using global approach and 6 (18%) met ASAS imaging criteria of sacroiliitis. Older age (mean 51.2 ± SD 12.5 vs 37.2 ± 14; p=0.04), history of dactylitis (50.0% vs 3.4%, p=0.03) and worse BASMI (4.1 ± 0.7 vs 2.4 ± 0.8, p=