DYNAMIC GADOLINIUM-ENHANCED MR-IMAGING IN ACTIVE AND INACTIVE IMMUNOINFLAMMATORY GONARTHRITIS

Dynamic T1-weighted FLASH MR imaging, obtained just after i.v. gadopen tetate dimeglumine injection, and pre- and postcontrast T1-weighted sp in-echo (T1-SE) MR imaging were performed to compare their information value with respect to inflammatory activity in immunoinflammatory gon arthritis. We examined 16 clinically active (CAG), 7 clinically inacti ve (CIG) and 4 healthy knees. The synovium of a preselected slice was outlined. Its area and relative signal intensity increase after gadope ntetate dimeglumine on T1-SE and FLASH (at each time t) were calculate d. The CAG knees showed a mean signal intensity increase on early dyna mic FLASH images higher by far than the CIG knees, while no significan t difference was found on spin-echo images obtained 5 to 15 min after contrast injection. The early signal enhancement probably reflects the perfusion and capillary permeability of the synovium. The area of syn ovium could differentiate between healthy and arthritic knees. Gadolin ium-enhanced dynamic FLASH imaging may provide clinically useful infor mation about the actual inflammatory activity of arthritic joints.