Last update:
16-Dec-2013

The current strategies of treatment of juvenile idiopathic arthritis (JIA) have achieved a significant reduction or even prevention of structural joint damage and associated functional disability. The trend towards early suppression of inflammation aimed at the prevention of erosive disease has shifted the emphasis away from the detection of structural damage by conventional radiography to the early detection of signs of disease activity and damage that can be achieved by ultrasonography (US) and magnetic resonance imaging (MRI). US has been shown to be superior to clinical examination in detecting synovitis, tenosynovitis and enthesitis. MRI provides a precise quantification of synovitis and can capture bone marrow edema and erosions early in the disease course in children with chronic arthritis. With the use of MRI and US a high frequency of subclinical synovitis has been demonstrated in patients with JIA who have clinically inactive disease. As a result, although no single modality currently meets every imaging need, imaging has become a major area of clinical investigation in pediatric rheumatology. The particular anatomical attributes of the growing skeleton, howewer, present considerable limitations in imaging interpretation. Thorough knowledge and experience of pediatric US and MRI anatomy at different ages are required for the examiner to establish whether the observed changes are pathological or part of normal development. Further limitation is derived from differences in the progress of articular damage between JIA and rheumatoid arthritis that make the standardized imaging schemes that are successfully performed in adults unsuitable for use in children. In this context, close cooperation between the pediatric rheumatologist and the pediatric radiologist is imperative for optimization of the management of children with JIA.

Key words: Juvenile idiopathic arthritis, Magnetic resonance imaging, Ultrasonography.