[Rheumatoid arthritis: echographic study of lesions of the periskeletal soft tissues].

The role of US was investigated in the study of rheumatoid arthritis, since the method depicts the changes in the periskeletal soft tissues--i.e., where the disorder preferably locates in both its early and late phases. A hundred and fifty-eight patients affected with rheumatoid arthritis according to American Rheumatism Association criteria were examined: the hand (wrist, carpus, metacarpus and fingers), the knee and the foot (metatarsus and toes) were studied in all patients. The study population was divided into two groups according to the time of onset of the disease: in 82 of them (52\%) the onset of symptoms dated back to less than a year, while 76 of them (48\%) had been suffering for over a year. US appears as the most accurate method to study the early phases of rheumatoid arthritis, for it makes early diagnosis possible, thus allowing the correct treatment to be chosen and preventing the disease from causing the irreversible lesions which progressively disable the patient. In the early phases of rheumatoid arthritis, US detects the exudative effects of synovial inflammation in periskeletal soft tissues. Joint effusions and synovial pannus are also depicted by US, as well as the thickening of tendon sheaths and tendon ruptures and rheumatoid nodules. In the late phases of rheumatoid arthritis, US supports conventional radiology, the latter remaining the irreplaceable method of choice to demonstrate skeletal lesions. Nonetheless, in such phases US yields further information on periarticular soft tissue involvement which no other method would make available--e.g., the presence of effusions, bulgings, synovial pannus, joint cartilage erosions, damaged tendons and sheaths, hypoplasia of the muscles ending on the involved joint and finally periarticular changes. Finally, US proves of great value in the early demonstration of reactivating phases, with unquestionable prognostic advantages.