2019 Volume 31 Issue 2 Pages 88-97
Plain radiographic examination is a basic tool used to assess joint damage in RA. Radiograph shows pocket erosion in bare areas, joint space narrowing and roughness of subchondral bone in RA. Modified total Sharp score is a useful method for the evaluation of small changes of joints in early stage of RA. However, only small joints in hands and feet are assessed by this scoring system. We developed the ARASHI scoring system for the evaluation of large joint damage in RA. This scoring system is well related to Larsen grade and further detail of large joint changes can be evaluated.
Ultrasonographic（US）examination in RA is a very useful tool to make early diagnosis and to evaluate efficacy of treatment. Thickness of synovium and effusion are detected using gray scale method of US, and abnormal vascular signal can be detected by power Doppler method. Sensitivity and specificity for detecting synovitis using us is as high as MRI. Power Doppler signal is strongly related to subsequent joint damage.
MRI is more sensitive than conventional radiography in detecting bone erosions in early RA. MRI erosion is detected as a well-defined area of abnormal signal. MRI can identify bone edema in patients with RA which cannot be visualized by radiographic technique. Bone marrow edema has been described as an ill-defined area of abnormal signal intensity. The presence of bone marrow edema can be a marker of inflammatory activity of RA and be defined as a pre-erosive lesion which enables us to predict joint damage.
