MRI features of pigmented villonodular synovitis (PVNS)

Area of Science:

• Radiology
• Orthopedic Imaging
• Musculoskeletal Imaging

Background:

• Pigmented villonodular synovitis (PVNS) is a rare, benign neoplastic proliferation of the synovium.
• Accurate diagnosis of PVNS is crucial for appropriate management and preventing joint damage.

Purpose of the Study:

• To characterize the magnetic resonance imaging (MRI) features of pathologically proven pigmented villonodular synovitis (PVNS).
• To identify specific MRI findings that are diagnostic for PVNS.

Main Methods:

• Retrospective review of radiographs and MRI scans from 23 confirmed PVNS cases.
• Detailed analysis of MRI findings, including synovial proliferation, joint effusion, bone erosion, and hemosiderin deposition.
• Evaluation of different MRI sequences, particularly fast field echo (FFE), for visualizing hemosiderin.

Main Results:

• PVNS commonly affects the hip, knee, ankle, elbow, and wrist, with a mean patient age of 36.
• Typical MRI findings include synovial proliferation, joint effusion in all cases, and bone erosions in 15 cases.
• Hemosiderin deposition within synovial masses, appearing as a low signal area best visualized on FFE sequences, is a key diagnostic indicator.

Conclusions:

• MRI is highly effective in diagnosing PVNS.
• The presence of hemosiderin deposits, visualized as low signal intensity on MRI (especially FFE sequences), is diagnostic for PVNS.
• MRI findings of synovial proliferation, effusion, and erosion, coupled with hemosiderin visualization, confirm PVNS.