Imaging comparison for avascular necrosis of the femoral head induced by different etiologies / 中国组织工程研究

ABSTRACT

bone fracture, mild col apse of the articular surface;femoral head deformation, bone fracture, articular surface col apse, hip degeneration. MRI of four categories of avascular necroses appeared as phase Ⅰ:line-like low signal of weight-bearing area of femoral head on T1WI, high signal on T2WI as the main change. Phase Ⅱ:clear boundary crescent-shaped uneven signal on T1WI, T2WI displayed moderately higher, uneven slightly lower signal around, showing a typical two-line sign. Phase Ⅲ:femoral head deformation, subchondral fracture, col apse, crescent formation, zonal low signal on T1WI, medium or high signal on T2WI. Phase Ⅳ, Ⅴ:complete destruction of articular cartilage, joint space narrowing, significant col apse and deformation of the femoral head, non-specific secondary osteoarthritis of the acetabulum, such as sclerosis, cystic degeneration and marginal osteophyte. The X-ray, CT, MRI performances of four types of avascular necroses at the same period were basical y the same.