[Imaging of joints in children].

Magnetic resonance imaging (MRI) has became the technique of choice for noninvasive imaging of the joint in the child, owing to its high tissular contrast. Through injection of paramagnetic contrast media, MRI allows a precise analysis of the synovial inflammation, of the cartilage and of the joint effusion. It offers a precise evaluation of the local activity of the disease. It guides and provides monitoring of local treatment in juvenile chronic arthritis and haemophilic arthropathy. The technique is very sensitive but lacks specificity. Its use is complementary to clinical examination and standard radiography techniques, which remain the initial investigations.