Feasibility of MRI in diagnosis and characterization of intra-articular synovial masses and mass-like lesions

Abstract

Abstract Background Classifications of intra-articular masses are infectious granulomatous diseases, non-infectious synovial proliferative processes (synovial chondromatosis, lipoma arborescens, rheumatoid arthritis, pigmented villonodular synovitis [PVNS]), vascular malformations, deposition disorders, neoplastic, and miscellaneous conditions. The aim of this study is to correlate the results of MRI with arthroscopy in characterization of different varieties of intra-articular synovial masses and mass-like lesions. This observational prospective study was conducted between February 2018 and August 2019. We screened 1000 routine musculoskeletal MRI examination during this period, 32 of which showed intra-articular synovial masses/mass-like lesions. The selected 32 patients (20 males and 12 females) have a mean age of 49.20 ± 2.0 years; all presented with joint swelling, pain, or difficulty of movement according to the joint affected. All patients underwent arthroscopy for histopathological correlation. Results The final diagnosis was synovial chondromatosis in 14 patients (43.8%), PVNS in ten patients (31.3%), and lipoma arborescens in five patients (15.6%). Synovial chondrosarcoma, synovial hematoma, and synovial ganglion cyst each in one patient (3.1%). The concordance of MRI to arthroscopy was 96.6% accuracy, 91.7% sensitivity, 99% specificity, 52.3% PPV, and 99.9% NPV. Conclusion Good correlation was observed between MRI and arthroscopy in diagnosis of intra-articular synovial masses/mass-like lesions.