Ultrasmall Superparamagnetic Particles Of Iron Oxide (USPIO)-enhanced MR Imaging Of Synovial Macrophages In A Rabbit Model With Antigen-induced Arthritis: A Preliminary Study

Backgrounds and Objectives Rheumatoid arthritis (RA) is a disease that is considered as an autoimmune disorder characterized by synovial inflammation and pannus formation at early phase. As the disease developed, destruction of cartilage and bone has often occurred. At the phase of synovitis, there are numerous inflammatory cells, especially macrophages, which infiltrated in synovial membrane and junction of cartilage/pannus. Once stimulated, macrophages would overexpress MHC-II molecular, proinflammatory factor, regulator cytokine, chemotatic factor and growth factor, et al. These factors form a cascade network to promote the development of RA. As it plays a crucial role in the progress of RA, macrophages is a hot topic in RA researches.However, the problem is wether we can image macrophage with those imaging modalities utilized now.Although some achievements have been made in fields of immunopathogenesis and therapeutics, etc, many problems on RA remain unsolved. There were lots of radiological studies on RA, but they were relatively behind compared to other subjects. In recent years, application of MRI in RA studies has became a tendency becacuse of its high resolution in soft tissue, flexible imaging modes and alternative imaging sequences. Hence, MRI has the advantage to detect the early pathological change of RA. Meaningfully, with the aids of specified molecular MR media, such as ultrasmall superparamagnetic iron oxide (USPIO) used in our study, MRI can detect the cellar activities in RA, and then open a novel door to molecular imaging for RA. Meanwhile,...