Nuclear magnetic resonance imaging (MRI) was used to study the normal knee. As well as revealing bone quality, MRI provided useful information on intra-articular and extra-articular soft tissues. Midsagittal views gave clear images of the cruciate ligaments, and of the patellar and quadriceps tendons. Parasagittal views were the best for delineating the menisci which, like ligaments and tendons, are of low intensity; the semimembranosus tendon and its insertion to the proximal tibia were also seen clearly in these views. The cruciate ligaments and menisci, though visible in the coronal view also, were better seen in the sagittal view. Axial views provided information on the structure of the patella, its cartilage, the patellofemoral joint and posterior soft-tissue structures.

Magnetic resonance images (MRI) were obtained of 10 healthy volunteers and 70 patients suffering from various orthopaedic disorders. Selected images of soft tissue, joint, bone and spinal abnormalities are presented and their interpretation is described. Although we have been using MRI for only a very short time, it is already possible to see its advantages: it provides good images of soft-tissues, detailed pictures of bone marrow, and excellent visualisation of the spine and spinal cord. The decision-making process in surgical procedures will in the future be influenced by this technique.