MRI ankle in juvenile idiopathic arthritis and its comparison with clinical disease activity scores

Abstract

Objectives: Juvenile idiopathic arthritis (JIA) is a common cause of morbidity and consequent disability among youth up to 16 years of age. Our study aims to image the ankle joints of JIA patients and correlate the findings with the clinical disease activity scores. Juvenile Arthritis Disease Activity Score (JADAS-27) is used by pediatricians to assess disease activity in JIA patients. There are four factors that determine this score – Global assessment of disease activity by the physician as well as patient/parent, joint count with active disease, and erythrocyte sedimentation rate (ESR). However, these clinical scores are dependent on the clinician’s experience and observation and, therefore, subjective. Material and Methods: Thirty patients of either sex with a clinical diagnosis of JIA as per the International League of Association for Rheumatology definition with clinically involved ankle joints were included in the study. Chronic arthritis due to other causes, such as infection, trauma, and so on, was excluded. All clinically diagnosed cases of JIA were subjected to magnetic resonance imaging (MRI) evaluation on Siemens Skyra 3 Tesla High-Resolution MR system using a dedicated coil for the ankle joint. Six sub-joints for each patient are evaluated, namely - The tibiotalar joint, subtalar joint, calcaneocuboid joint, calcaneonavicular joint, naviculocuneiform joint, and tarsometatarsal joint. Image analysis and scoring shall be done for each patient at each joint as per the Juvenile Arthritis MRI SCORE, consisting of the following parameters-synovial hypertrophy score, cartilage lesion score, bone erosion score, and bone marrow change score. Each of these scores is calculated individually based on the percentage of involved bone volume. All individual scores were summed to get the total MRI Score. The data collected were then statistically analyzed. Results: A positive correlation was sought between the JADAS-27 score and the total MRI score with the P-value being 0.03. A positive correlation was also found between the total MRI score and the ESR value of the patient (P - 0.02). Conclusion: MRI findings can be a potential marker of disease activity in JIA patients and these findings could also predict the prognosis accurately in these patients. The findings are objective and comparable to the aforementioned clinical scores.