Diagnostic value of high resolution B-mode and doppler sonography for imaging of hand and finger joints in RA

Abstract

High-resolution sonography enables a detailed assessment of intra-articular and extra-articular soft tissue abnormalities of joints affected by rheumatoid arthritis (RA). B-mode sonography and power Doppler should be interpreted together with findings of clinical examinations and conventional radiography. In patients with RA, the wrists, the metacarpophalangeal joints, and the proximal interphalangeal joints can be involved and thus should be assessed with ultrasound in B-mode and power Doppler application, using a standardised technique. This examination can be time-consuming and for this reason multiple publications recommend to limit the examination to the most commonly involved joints such as the second and third MCP and PIP and the radiocarpal and radioulnar joints. The severity of acute synovitis correlates with the increased vascularity. With power/colour Doppler the inflammation is documented on a 3-point scale score which is suitable for follow-up examinations. Radiographs remain the baseline imaging modality for assessment of erosions but these are also easily detected by sonography. Sonography detects 20% more abnormalities than does radiography, and sonography has the potential to provide simple grading of disease activity. Thus, together with blood tests, sonography is excellent for monitoring the disease activity in RA and is considered as an extended diagnostic arm for clinical decisions. Learning objectives: 1. Understand the pathogenesis in RA that results in erosions and synovitis. 2. To be familiar with the sonographic findings and scoring systems. 3. Differentiation of osteoarthritis from RA.