By Bone Group 2013-10-24,CASE DISCUSSION,History,Male,29Y Complaint:bilateral knee pain with intermittent fever for 4 years,Key signs？ Your impression？ DDX？,Laboratory examination Uric Acid（UA）：478.3mol/L Treatment Allopurinol（ALLO）,Final diagnosis,Gouty Arthritis,Background,Gout is a form of inflammatory arthritis that is characterized initially by acute attacks of active synovitis related to the presence of monosodium urate (MSU) crystals in the joints and periarticular soft tissues. Accounting for 3-7 in panarthritis Men40 years old Genetic predisposition,Background,Most classically in the first metatarsophalangeal joint (toe) A history of underlying renal disease or use of medications that cause hyperuricemia Gold standard : monosodium urate (MSU) crystals in the joint fluid or tophus,Pathogenesis,MSU crystals Lipids Protein Mucopolysaccharides The tophus eroding the underlying bone is pivotal in the development of bone erosions in gouty arthritis. MSU crystal deposition is associated with the presence of underlying OA.,Radiologic hallmarks,Presence of macroscopic tophi Normal mineralization Relative joint space preservation Erosions with overhanging edges A gradually expanding tophus eroding at the bone cortex with concomitant new periosteal bone formation trying to contain the tophus Asymmetric polyarticular distribution,X-RAY,Chronicity of the disease process Only 45,only 6-8 years “Punched out” Until 612 years after the initial acute attack,CT,82% visible tophi Large erosions 7.5 mm diameter,MRITophi,T1WI Homogeneous and generally isointense to muscle T2WI Varied Intermediate to low heterogeneous signal intensity A variable enhancement Peripheral enhancement pattern,DDX,Chondrocalcinosis (pseudogout) Rheumatoid arthritis (RA) Pigmented villonodular synovitis（PVNS）,Chondrocalcinosis,Commonly found in the elderly Mostly occuring in the knee joint Deposition of different types of crystals in the hyaline articular cartilage and/or fibrous cartilage of the menisci Predominant：Calcium pyrophosphate dihydrate (CPPD) Produce severe degenerative joint disease (pyrophosphate arthropathy),Radiographic hallmarks,Articular and periarticular calcification Only involving 1 or 2 joints Discrete areas of low signal intensity within the articular cartilage More apparent on GRE sequences Joint space narrowing Subchondral osteosclerosis Articular surface subsidence,RA,Characterized by an inflammatory synovitis and a potential to destroy bone and cartilage Mostly seen in middle-aged woman Symmetric distribution RF（+）,Radiologic hallmarks,Extensive and diffuse synovial hyperplasia and inflammation Synovial pannus formationMarked enhancement Serious articular cartilage degeneration（Grade or ） Local marginal erosions Obvious local osteoporosis Joint space narrowing in early stage，even fusion,PVNS,Characterized by synovial proliferation and hemosiderin deposition into the synovial tissues of the affected joint Men aged 20-40 years old Mostly seen in knee and ankle joint Proliferation（villous/nodular/mixed) Nodular variety commonly seen in the tendon sheaths, principally on the volar aspect of the phalanges,Radiologic hallmarks,Variable extent of synovial proliferation Joint effusion and erosion of bone Deposit of hemosiderin within the synovial masses Low signal on both T1WI and T2WI Best seen on FFE sequence,Treatment,Colchicine Not an accurate tool to diagnose gout(psoriatic arthritis&pseudogout) Cold applications A useful adjuvant treatment(RA),Conclusion,Plain radiographs are less sensitive to early changes in chronic gout than other imaging techniques. CT may be the most specific imaging technique when evaluating intraosseous lesions, while MRI could be the preferred technique to evaluate chronic synovial involvement. The presence of structural changes in radiographs correlates with poor function, and is associated with irreversibility of changes.,