Imaging in rheumatology

Abstract

Plain films continue to be central to the diagnosis and monitoring of rheumatological diseases. Imaging has a particular role to play in identifying disease in its earliest stages. Ultrasound and MRI permit the detection of subclinical joint inflammation. Ultrasound is helpful in guiding diagnostic and therapeutic interventions. Despite the increasing availability of modern imaging techniques such as ultrasound and MRI, conventional radiographs (CRs) remain fundamental to rheumatological imaging, playing an important role in the diagnosis and monitoring of the arthritides. Evaluation of plain films includes an assessment of the soft tissues for swelling and calcification. The joint space on CRs reflects the thickness of articular cartilage and is typically lost as a result of arthropathy. Evaluation of the periarticular bone will reveal the presence of erosions, osteophytes, subchondral bone changes, such as cysts and sclerosis, and changes in bone density. Finally, plain films allow an assessment of joint alignment and, in the case of hand and foot films, give an indication as to the distribution of disease. Despite the wide use of the CR in the evaluation of the arthritides, it has the disadvantage that it is relatively insensitive to the early changes of disease and changes occur relatively slowly. In the early stages of arthritis, when therapy may have the greatest impact and where structural abnormalities may be reversible, radiographically defined joint damage is not a prominent feature. MRI and ultrasound have the ability to diagnose arthritis earlier, detect changes in disease status more rapidly and increase the clinical understanding of the disease.