Bilateral knee pain and osteoarthritis. Sclerosis in distal femurs on knee radiographs of unclear etiology. Evaluation is somewhat limited by motion artifact.MENISCI: There is globular high T2 signal within the body of the medial and lateral menisci compatible with degeneration. In addition, there is linear high signal within the posterior horn of the medial meniscus compatible with a horizontal tear that does not extend to the articular surface.ARTICULAR CARTILAGE AND BONE: There is mild thinning of the articular cartilage of the medial patellar facet and within the medial and lateral compartments but no full-thickness cartilage defects are identified.The bone marrow signal throughout the distal femoral and proximal tibial and fibular diaphyses is markedly low on T1-weighted images with heterogeneous high T2 signal throughout. There is relative sparing of the epiphyses. No evidence of bone infarct.LIGAMENTS: The anterior cruciate and collateral ligaments are intact. There is thickening and ill-defined increased T2 signal in the PCL however the fibers are intact. EXTENSOR MECHANISM: The extensor mechanism is intact.ADDITIONAL
Abnormal marrow signal with relative sparing of the epiphyses. This finding can be seen in marrow replacement and infiltrative marrow processes. Although less likely, a malignant process cannot be entirely excluded.