[Magnetic resonance imaging of the joints: a revolution for the practicing rheumatologist].

In the last 15 years, new imaging techniques have changed the life of practicing rheumatologists in terms of both diagnostic approach and knowledge of disease mechanisms. Clinical symptoms, disease signs and the results of physical examination have been more closely related to their anatomical basis. In particular, magnetic resonance imaging allow diagnosis of disease in its early phase and its follow-up with a previously unknown sensitivity. Novel imaging studies have contributed to elucidate several pathogenetic mechanisms in musculoskeletal diseases, such as rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, polymyalgia rheumatica and osteoarthritis; allow evaluation of the real degree of joint inflammation, which is often uncoupled from clinical signs; and possibly reduce the need for large clinical trials. In conclusion, new imaging techniques and refinements of the established techniques have opened exciting perspectives in our understanding and treatment of many rheumatic diseases. Much attention should be paid to the training of new generations of rheumatologists in this field.