Standard radiographs of Rheumatoid Arthritis Larsen A, Dale K, and Eek M, 1975 From the Department of Radiology, Oslo Sanitetsforening Rheumatism Hospital. The present system for evaluation of rheumatoid arthritis is a complete modification of the system presented by A. Larsen (1). Experiences using this modification have been presented by K. Dale and M. Eek (2). This system is not specific for rheumatoid arthritis. For example, it can also be used in psoriatic arthropathy and ankylosing spondylitis with peripheral joint involvement. For further information see Acta Radiologica (3). The evaluation of arthritis is made by comparing a joint radiograph with the same joint in the film series, using also the following definitions and instructions. Grade 0. Normal conditions. Changes not related to arthritis, for example bone deposition, may be present. Grade I. Slight abnormality. One or more of the following changes are present: periarticular soft tissue swelling, periarticular osteoporosis and a slight joint space narrowing. When possible, use for comparison a normal contralateral or a previous radiograph of the joint in the same patient as grade 0, as demonstrated in standard films. Soft tissue swelling and osteoporosis are sometimes reversible changes. This is an early, uncertain phase of arthritis. The compatible changes may occur without arthritis in old age, in traumatic conditions, in Sudeck’s artrophy etc. Grade II. Definite early abnormality. Erosions and joint space narrowing corresponding to the standards. Erosion is obligatory except in the weight-bearing joints (in standard films erosion is present in all joints except tarsus). Grade III. Medium destructive abnormality. Erosion and joint space narrowing corresponding to the standards. Grade IV. Severe destructive abnormality. Erosion and joint space narrowing corresponding to the standards. Bone deformation is present in the weight-bearing joints. Grade V. Mutilating abnormality. The original articular surfaces have disappeared. Gross bone deformation is present in the weight-bearing joints. 1. Larsen A: A radiological method for grading the severity of rheumatoid arthritis (thesis), Helsinki, 1974. 2. Dale K and Eek M: Preliminary experiences with Larsen’s radiological method for grading rheumatoid arthritis. Scand J Rheumatol, Vol 4, Suppl 8, abstract 2702, 1975. 3. Larsen A, Dale K and Eek M: Acta Radiologica Diagnosis 18 (A77) 4: 481-491.