title: Imaging of intraarticular masses.
abstract: Intraarticular masses can be classified as noninfectious synovial proliferative processes (lipoma arborescens, synovial osteochondromatosis, pigmented villonodular synovitis, rheumatoid arthritis), infectious granulomatous diseases (tuberculous arthritis, coccidioidomycosis arthritis), deposition diseases (gout, amyloid arthropathy), vascular malformations (synovial hemangioma, arteriovenous malformations), malignancies (synovial chondrosarcoma, synovial sarcoma, synovial metastases), and miscellaneous (cyclops lesion). Knowledge of articular anatomy aids the radiologist in localizing masses to the joint space. Some joints have complex anatomy with contiguous or adjacent bursae, recesses, and tendinous connections from which masses may originate or into which masses may extend. Many of the diseases causing intraarticular masses have specific imaging characteristics, especially on magnetic resonance images, and knowledge of these characteristics will allow for a more confident diagnosis.
authors.affiliation: Department of Radiology, University of Southern California Keck School of Medicine, 1200 N State St, Suite 3550, Los Angeles, CA 90033, USA. psheldon@usc.edu
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Sheldon
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Forrester
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Learch
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011859:Radiography