ABSTRACT
Objective To explore the imaging characteristics of pigmented villonodular synovitis(PVNS) of knee joint.Methods X-ray,CT and MR imaging features of PVNS of knee confirmed by operation,arthroscope and pathology were retrospectively analysed with literatures review.Results X-ray could only show the swelling of the joint cpasules,the destruction,defect and sclerosis of the bone under the articular surface.CT could show the soft tissue nodules in joint cavity projected from joint capsule.MRI was sensitive in showing the thickened synovium of joint and joint effusion,the soft tissue nodules and thickened synovium of joint were iso-or low signal intensity on T1WI,isointensity in one and low or slight hyperintensity in 4 on T2WI.Multiple haemosiderin deposit nodules were seen in the thickened synovium,which were low signal intensity on T1WI and T2WI in 4 cases,and the nodules were enhanced obviously on contrast-enhanced MR images.Conclusion MRI possesses obviously in diagnosis of PVNS of knee joint than X-ray and CT,which is helpful in diagnosis and differential diagnosis of PVNS of knee joint.