"Arthrography diagnosis of synovial cysts of the knee.".
A lateral view of the knee in 90 degree flexion can reveal popliteal cysts which do not show on routine arthrography. Flexion causes transfer of intra-articular fluid to the posterior portion of the joint space, lowering pressure within the cyst and allowing it to fill with contrast media.
D006801:Humans; D007719:Knee Joint; D011859:Radiography; D013581:Synovial Cyst / Q000000981:diagnostic imaging*