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MR imaging of pigmented villonodular synovitis of the knee
Y Araki1, H Tanaka, H Yamamoto
1Department of Radiology, Osaka Rosai Hospital, Japan.
Abstract:
Six cases of pigmented villonodular synovitis (PVNS) of the knee are presented. MR imaging and surgical proof were available in all cases. Three of the six cases showed the diffuse form, and the other three cases the localized form. The MR appearance of PVNS varied, presumably according to the relative proportion of pathological components. It most commonly consisted of scattered low signal intensity areas representing hemosiderin deposition in hypertrophied synovium on T2(*)-weighted images, and dotted areas of low signal intensity, presumably resulting from fibrous components of the lesion, on T1-weighted images. The latter finding is described for the first time in this report. Two cases were associated with osteoarthritis. In the remaining four cases, the osseous structures, cruciate ligaments, and menisci were normal. MR imaging was of great use in the detection of PVNS. For the first time, a preoperative diagnosis of PVNS of the knee joint could be made by MR imaging.
Insights
Magnetic resonance (MR) imaging is highly effective for diagnosing pigmented villonodular synovitis (PVNS) of the knee. This study details MR findings, aiding in preoperative diagnosis of this knee condition.
Area of Science:
- Orthopedic Surgery
- Radiology
- Pathology
Background:
- Pigmented villonodular synovitis (PVNS) is a rare condition affecting the knee joint.
- PVNS can present in diffuse or localized forms, impacting synovial tissue.
- Accurate preoperative diagnosis is crucial for effective management of knee PVNS.
Purpose of the Study:
- To evaluate the utility of magnetic resonance (MR) imaging in diagnosing pigmented villonodular synovitis (PVNS) of the knee.
- To correlate MR imaging findings with pathological components of PVNS.
- To assess the diagnostic accuracy of MR imaging for PVNS of the knee.
Main Methods:
- Retrospective review of six knee cases with confirmed pigmented villonodular synovitis (PVNS).
- Analysis of MR imaging features, including T1-weighted and T2(*)-weighted images.
- Correlation of MR findings with surgical and pathological data.
Main Results:
- MR imaging demonstrated characteristic findings in PVNS, including hemosiderin deposition (low signal on T2(*) images) and fibrous components (low signal on T1 images).
- Distinct MR appearances varied based on the proportion of pathological components in diffuse and localized PVNS.
- MR imaging successfully identified PVNS in all six cases, enabling preoperative diagnosis.
Conclusions:
- MR imaging is a valuable tool for the detection and preoperative diagnosis of pigmented villonodular synovitis (PVNS) of the knee.
- Understanding the varied MR appearance of PVNS is essential for accurate interpretation.
- This study highlights the novel finding of dotted low signal intensity areas on T1-weighted images, indicative of fibrous components in PVNS.