Evaluation of pannus and vascularization of the metacarpophalangeal and proximal interphalangeal joints in rheumatoid arthritis by high-resolution ultrasound (multidimensional linear array)

Objective. To evaluate the extent of intraarticular vascularization and pan nus formation in metacarpophalangeal (MCP) and proximal interphalangeal (PI P) joints of patients with rheumatoid arthritis (RA) by high-resolution ult rasound (US), Methods. A newly developed, high-resolution multidimensional linear array U S was utilized to obtain longitudinal and transverse scans of joints with a ctive RA (n = 21), moderately active RA (n = 39), or inactive RA (n = 93), and of joints from healthy controls (n = 120), Results. Healthy joints had no detectable pannus, whereas pannus could be d etected in 52% of the joints with active RA, 82% of the joints with moderat ely active RA, and 67% of the joints with inactive RA, There was a signific ant difference in vascularization in the joints of all subgroups of RA pati ents and those of healthy subjects (P < 0.001), Moreover, vascularization d iffered significantly among the RA subgroups: inactive versus moderately ac tive RA (P < 0.02) and inactive versus active RA (P < 0.05), Both pannus an d vascularization appeared to be localized preferentially on the radial sid e of the joints. Conclusion. Evaluation of pannus and the extent of vascularization within t he joints of patients with RA by high-resolution US might be helpful in the assessment of disease activity, and thus influence therapeutic strategies.