MAGNETIC-RESONANCE-IMAGING IN PIGMENTED VILLONODULAR SYNOVITIS

The magnetic resonance imaging (MRI) appearance of pigmented villonodu lar synovitis of the knee is described for three patients. In the imag es for one patient diffuse areas of low signal intensity reflecting he mosiderin deposits suggested the diagnosis. For another patient with t he diffuse form of the condition but minimal hemosiderin deposition, i dentification of diffuse synovial proliferation in the MRI images guid ed diagnostic percutaneous biopsy. For the third patient, who had loca lized pigmented villonodular synovitis, MRI after administration of a gadolinium chelate facilitated identification of localized synovial pr oliferation and guided diagnostic arthroscopic biopsy. The authors dis cuss the value of MRI in the diagnosis of all forms of this uncommon c ondition and the various signal characteristics that it may produce.