Diagnostic Value of Whole-Body MRI in Pediatric Patients with Suspected Rheumatic Diseases.

Background and Objectives : The diagnosis of rheumatic diseases in children is challenging and requires the use of advanced imaging examinations such as whole-body magnetic resonance imaging (MRI). Whole-body MRI allows visualization of bone marrow edema (BME), muscle edema, joint effusion and changes in the soft tissues surrounding the joints. The aim of this study was to collect and compare whole-body MRI findings, laboratory results and clinical manifestations of pediatric patients with suspected rheumatic disease. Materials and methods : In this retrospective single-center study, 33 patients who underwent whole-body MRI were included. Their age ranged from 9 to 17 years, and 24 (72.73%) of the patients were female. Patients were diagnosed as follows: juvenile idiopathic arthritis (27.27%), juvenile idiopathic inflammatory myopathies (21.21%), chronic nonbacterial osteomyelitis (21.21%) and other medical conditions (30.30%), such as arthritis associated with infection, scleroderma, Takayasu arteritis, polyarteritis nodosa and joint damage. Results : The most common symptom reported by 26 (79.79%) patients was pain. On physical examination, the limitation of joint mobility was examined in 17 (51.51%), swelling of the joints was observed in 12 (36.36%) patients and decreased muscle strength was noticed in 11 (33.33%) patients. An increase in the C-reactive protein (12%), erythrocyte sedimentation rate (9%), leukocyte count (9%) and creatine kinase (CK) (18%) was observed. Whole-body MRI revealed myositis (30%), joint effusion (27%) and BME (24%). The statistical analysis showed a significant relationship between myositis and the elevated CK level ( p < 0.05). Conclusions : The most common symptom in the studied population was pain, while the limitation of joint mobility was found in more than half of patients. Myositis was the most commonly imaged lesion on the whole-body MRI and it was related to an increase in the CK level.