RHEUMATOID-ARTHRITIS - FOLLOW-UP AND RESPONSE TO TREATMENT

Objective: To assess the role of diagnostic imaging techniques in the identification and follow-up of the anatomical damage induced by the c hronic inflammatory process of rheumatoid arthritis (RA) not only to s tudy the natural history of the disease but also and especially to ass ess the long-term response to disease-modifying anti-rheumatic drugs ( DMARD). Materials and methods: The relative literature data were revie wed and compared with our personal experience with different imaging m odalities such as conventional radiography (CR), ultrasound (US) and m agnetic resonance imaging (MRI). Results: Several radiologic technique s have been used over the years to study articular damage in RA: they describe and quantify the articular damage (semi-quantitative analysis ) based on a series of parameters and elementary anatomical lesions wh ich are given a rising score. For its sensitivity in detecting early d isease signs and the possibility to express anatomical damage progress ion quantitatively, Sharp's index is considered the best tool for eval uating RA patients. The close correlation between clinical parameters and the radiologic scores obtained regardless of the method applied le d to a new concept of anatomical damage related to the 'radiologic pro gression of the disease' which is a more precise measure of RA severit y than the single isolated radiograph. The progression of radiologic d amage in rheumatoid arthritis is expressed as the number or proportion of new eroded joints/year: independent of the index adopted and the t erms used to express progression, severe radiologic damage occurs in t he early disease stage, involving approximately 2% of the joints withi n about 1 year, and 13% within 2 years, with an estimated average annu al progression of 1.3%. Radiologic techniques evaluate the anatomical damage in the course of RA only with reference to the osseous componen t of the joint and therefore apply to a disease stage that is largely irreversible. MRI and US detect the soft-tissue damage occurring in th e earlier phases and are more likely to respond to early treatment. Th e former technique appears to be useful to detect soft-tissue damage l ike synovial pannus, intra- and periarticular and peritendinous effusi on, capsuloligamentous articular and tendon changes. Its high sensitiv ity for minimal bone erosions and chondromalacia has been demonstrated . US allows to demonstrate a wide range of soft-tissue changes of the hand and wrist. Joint-cavity widening, loss of cartilage definition, b one erosions, widening of flexor tendon sheath and tendon structure ar e also well depicted on ultrasound images. Conclusions: CR is the cent ral tool in the diagnosis, staging and follow-up of RA patients and in general in the assessment of treatment efficacy; MRI and US are compl ementary tools. (C) 1998 Elsevier Science Ireland Ltd. All rights rese rved.