MRI-Arthroscopic Correlation in Rotator Cuff Tendon Pathologies; A Comparison between Various Centers

    Background: Magnetic resonance imaging (MRI) has long been considered a perfect imaging study for evaluation of shoulder pathologies despite occasional discrepancies between MR reports and arthroscopic findings. In this study we aim to evaluate impact of imaging center as an indicator of image quality on accuracy of MRI reports in diagnosis of rotator cuff tendon pathologies. Methods: We reviewed MR reports of 64 patients who underwent arthroscopy in university center hospital. MRIs were done in various centers including both university-affiliated and out-centers. All studies were reported by two radiologists in consensus unaware of the arthroscopic results or previous reports. An inter-observer agreement analysis using the kappa statistics was performed to determine consistency among imaging and surgical reports. Results: Kappa values for out-centers were as follows: 0.785 for biceps, 0.469 for suscapularis, 0.846 for supraspinatus and 0.785 for infraspinatus tendons. In university centers values were 0.799 for biceps, 0.802 for suscapularis, 0.789 for supraspinatus and 0.770 for infraspinatus tendons. Conclusion: Image reporting in university centers with proficient sequences increased accuracy of diagnosis in 3/4 of evaluated features and showed subtle decreased inter-observer agreement in 1/4 of features. Uniformity of the scanners and protocols as well as evaluation on a workstation rather than hard copies cumulatively resulted in a meaningful increase in the accuracy of the same radiologists in diagnosis of rotator cuff tendon tear.