Increased prevalence of pelvic venous congestion sign on sacroiliac MRI in women with clinically suspected sacroiliitis

OBJECTIVE: To compare the prevalence of pelvic venous congestion (PVC) sign on sacroiliac and hip MRI in women of reproductive age as a possible cause of pain mimicking sacroiliitis. METHODS: This retrospective study included 727 MRI examinations (401 sacroiliac joint MRI and 326 hip joint MRI) that were performed between January 2010 and December 2017. Images were evaluated for the presence of sacroiliitis, presence of PVC sign and presence of other incidental findings of musculoskeletal and genitourinary disorders. After removing patients with other musculoskeletal and genitourinary disorders that may cause pain (n=188), remaining 539 (322 sacroiliac and 217 hip), MRI examinations were re-analyzed for the presence of PVC sign. RESULTS: Four hundred one patients with sacroiliac MRI examination had 120 (29.9%) PVC sign and 326 patients with hip MRI examinations had 54 (16.6%) PVC sign (p<0.001). After removing patients with other musculoskeletal and genitourinary disorders that may cause pain, 322 patients with sacroiliac MRI had 102 (31.7%) PVC sign and 217 patients with hip MRI examinations had 38 (17.5%) PVC sign (p<0.001). No significant difference was found between patients with acute sacroiliitis and patients without acute sacroiliitis concerning PVC prevalence (p>0.05). There were also no significant differences between other comparable incidental findings. CONCLUSION: Significantly increased PVC prevalence in sacroiliac MRI exams may be attributable to PCS simulating clinical sacroiliitis.