| Research Abstract |
We evaluated femoral perfusion in a non-traumatic rabbit serum sickness osteonecrosis model, using serial repetitive T2^*-weighted dynamic MRI and contrast enhanced MRI. The results indicated that microcirculatory disorder proceeded to histological osteonecrosis. Using the TUNEL reaction in rat with osteonecrosis, we have studied the death mechanism of the cell involved in osteonecrosis. The mechanism of cell death was apoptosis, which showed that apoptosis was not cause of osteonecrosis. In the prospective MRI studies of renal transplant patients, no bone marrow edema proceeding to band patterns was observed, which indicated that bone marrow edema would not be the cause of osteonecrosis of the femoral head (ONFH) in renal transplant patients. A cohort study was done, to compare the effect of two immunosuppressive agents, cyclosporine A and tacrolimus, in terms of the development of ONFH after renal transplantation. The risk of ONFH was reduced in the patients who used tacrolimus for i
… More
mmunosuppression. Whether ONFH could reduce or not during the natural course was investigated using a novel developed procedure named 3D-MR volume registration. The results showed some early necrotic lesions could reduce in size. We also evaluated long-term reparative process of osteonecrosis with minimum 10-years radiological follow-up and MRI at final examination, necrotic lesions without collapse except for early lesions did not show any sigh of progression of repair process. It was proved that lesion size and location were important prognostic indicators of collapse using novel three-dimensional indexes. We performed the first clinical trial, which showed significant preventing effect of collapse development by administration of alendronate. MRI screening for multiple osteonecrosis (MON) was performed in patients with ONFH. MON was found in about a half of steroid or alcohol related ONFH but none of idiopathic ONFH, which showed steroid-related or alcohol related ONFH are a systemic disease. Less
|
