[Ultrasonic diagnosis of inflammatory rheumatic diseases]

During the last two decades, sonography has become more and more important in the diagnosis of rheumatic diseases. With the development of high-frequency realtime transducers, detailed images of the musculoskeletal system can be provided. Furthermore, sonography or echocardiography is able to detect systemic manifestations of connective tissue diseases. Compared to plain films, which mainly evaluate bony lesions of inflammatory joint diseases, sonography is used to assess non-bony abnormalities (synovial membrane, cartilage, menisci, tendons) and synovial space. Pannus and effusion as indicators of inflammatory rheumatic disease can easily be examined by sonography. However, sonographic findings in rheumatic diseases are mostly nonspecific and can rarely be used to distinguish between different diagnoses, which is sometimes possible using plain x-rays (i.e., pencil-in-cup). Sonography has proven to be a meaningful diagnostic tool in evaluating tumors in subcutaneous tissue or muscles. The diagnostic results of musculoskeletal sonography are today compared to those obtained by computed tomography (CT) and magnetic resonance imaging (MRI). Although musculoskeletal MRI can visualize bony and non-bony structures at the same time, sonography is still of particular interest in the diagnosis of rheumatic diseases, because it is a noninvasive, widely available, relatively inexpensive imaging modality which can be rapidly performed and repeated.