4Mont MA,Hungerford DS. Non-traumatic avascular necrosis of the femoral head [J]. J Bone Joint Surg Am, 1995,77(3):459- 474.
5Mitchell DG, Rao VM, Dalinka MK, et al. Femoral head avascular necrosis:correlation of MR imaging,radiographic staging,ra- dionuclide imaging and clinical findings [J]. Radiology, 1987, 162(3) :709-715.
6Iida S,Harada Y,Shimizu K,et al. Correlation between bone marrow edema and collapse of the femoral head in steroid in- duced osteoneerosis[J]. Am J Roent,2000,174:735-743.
7Mitchell DG,Rao V,Dalinka M,et al. MRI of joint fluid in the normal andischemic[J]. Am J Roent, 1986,146:1215-1218.
