MRI and spondyloarthropathy: diagnostic performance compared to long-term clinical follow-up with evaluation of gadolinium chelates injection.

Abstract

To evaluate MRI performance on both initial and long-term rheumatologic diagnosis of spondyloarthritis (SpA), taking into account clinical evolution and treatment response, and the impact of gadolinium injection. In this single-center study, patients who underwent both spinal and sacroiliac (SI) joint MRI were prospectively recruited between May 2013 and January 2014 and followed for 7 years until 2020. Clinical, biological, and radiologic parameters were collected. At 7-year follow-up (2020), two independent readers reevaluated the initial MRI datasets for specific radiological features of SpA with a 5-point Likert scale to record the estimation of confidence. The centralized MRI interpretations were compared to the established rheumatologic diagnoses in 2013 and 2020. In total, 145 patients (52 men and 93 women) were included. During the 7-year follow-up, the number of patients with positive SpA diagnosis decreased from 93 to 58. Mean sensitivity, specificity, and accuracy of non-contrast MRI were 18, 97, and 49% and 27, 97, and 69% considering 2013 and 2020 rheumatologic diagnoses, respectively. Mean sensitivity, specificity, and accuracy values of gadolinium-enhanced MRI were 26, 97, and 54% and 38, 97, and 73% considering 2013 and 2020 diagnoses, respectively. Post-contrast MRI enabled identification of a subgroup of enthesis-only lesions, without any bone lesions, corresponding to 14% of the pathological cohort. It confirmed uncertain diagnoses in an additional 8.5% of pathological cases. MRI performance for SpA diagnosis is higher when long-term clinical follow-up is considered than when compared to initial diagnosis. Gadolinium injection increases MRI diagnostic performance and may demonstrate a pure enthesic form of the disease, without bone abnormality. • Compared to the rheumatologist's diagnosis over long-term clinical follow-up, MRI performance for SpA is higher than usually estimated. • Gadolinium injection increases diagnostic performance of MRI as it may identify a purely enthesis form of the disease. • Gadolinium injection should be discussed in patients for whom the diagnostic suspicion is strong and whose initial non-injected examination is normal or doubtful.