Editorial Comment on: I. Sudoł-Szopińska, E. Kontny, W. Maśliński, M. Prochorec-Sobieszek, B. Kwiatkowska, K. Zaniewicz-Kaniewska, A. Warczyńska The pathogenesis of rheumatoid arthritis in radiological studies. Part I and I. Sudoł-Szopińska, K. Zaniewicz-Kaniewska, A. Warczyńska, G. Matuszewska, F. Saied, W. Kunisz The pathogenesis of rheumatoid arthritis in radiological studies. Part II

Ultrasound (US) and magnetic resonance imaging (MRI) are the most promising imaging techniques for early detection of arthritis and its damage evaluation. The authors show accurately strengths and weaknesses of each method(1, 2). Joint US is especially useful in the acute phases of rheumatoid arthritis (RA), when there is active synovitis and joint effusion. Power Doppler allows detection of active synovitis with high sensitivity. However, this sensitivity is strongly dependent on the operator and on the technical features of the US system. The valid methods for scoring of synovitis described by the authors are not universally accepted by the scientific community. It is also not yet clear which and how many joints are to be scanned to obtain a good compromise between execution time and adequate information. This problem could arise because US is a relatively cheap and rapid technique: expert sonographers may want therefore to include in the count every accessible joint. Ironically, being less practical and accessible, MRI has become more standardized than ultrasound. A dedicate-low field device is sufficient for the needs of rheumatologists. Dedicated machines imply lower costs and more acceptance by the patient. Hand and wrist were chosen as more useful joints to follow the evolution of RA, although also the forefoot is an important area to examine. As correctly described in the article, gadolinium injection is a valid tool to assess the extension and intensity of synovitis and allows post-processing dynamic assessment. In particular, it allows to measure the rate of contrast enhancement (REE) and the maximum amount of contrast enhancement (RE). New semiquantitative software can measure the enhanced area of the synovium and differentiate areas that maintain the contrast from those with intense washout. This is useful to measure treatment efficacy and residual disease activity in patients in clinical remission. The information derived from these imaging techniques, in combination with clinical data, will facilitate early diagnosis, prediction of erosions and of the more aggressive subset of disease. Equally important are the ability to increase the sensitivity of clinical examination, to evaluate treatment efficacy and residual disease activity in patients in clinical remission. In this complete description of the state of the art of imaging techniques, the authors explain the contribution that the radiologist can provide to the clinician. In real life, examinations used mainly in research or clinical trials can be seldom used. Limitations and strengths of the local reality, including availability of specific machines and training of the radiologist, should be kept in mind. The rheumatologist should meet the radiologist before the examination to discuss clinical needs and after the examination to evaluate the results. The radiologist should suggest the most appropriate method to answer the clinical questions. This collaboration is likely to increase the proficiency of the examination and decrease the associated costs, a major result in times of economic constraints.