Comparison of musculo-skeletal USG and radionuclide soft tissue scintigraphy in the evaluation, selection and follow-up of patients for radiosynoviorthesis

Full text: The main objective of this study was to compare and correlate the information obtained from high resolution ultrasound (USG) and soft tissue scintigraphy in the evaluation of painful joint disorders and follow-up of patients after Radiosynoviorthesis. Thirty-two patients suffering from painful joint disorders including Rheumatoid Arthritis were prospectively studied. High resolution ultrasonography of joints was performed with a 15 MHz transducer. Soft tissue scintigraphy of joints were performed in a single head gamma camera with leap collimator 15-20 minutes after injecting 20-25 mCi of Tc-99m MDP. Anterior, posterior, lateral and if needed oblique views were obtained. Delayed images of joints were also obtained. High resolution USG demonstrated effusion, synovial proliferation, thickening, Backer's cyst and bone erosion effectively, and was very useful in guiding aspiration. On the other hand soft tissue scintigraphy was found to be more sensitive in detecting active synovial inflammation and showed excellent correlation with clinical features. The earliest changes after therapy were reduction in the intensity of uptake in soft tissue scintigraphy and reduction of degree of effusion in USG. Delayed phase bone scans were helpful for assessment of extent and severity of disease and deformity. We conclude that soft tissue scintigraphy is a better indicator of the active synovial inflammation having better correlation with clinical features. Hence it is better suited for selecting patients for radiosynoviorthesis. Ultrasound however was found to be a better tool for detecting and treating associated effusion. The earliest changes of treatment response were changes in soft tissue uptake and reduction of effusion. (author)