骨梗死的影像学改变及病理表现

目的 探讨骨梗死的病理演变及其影像学表现。方法6例骨梗死中5例行平片检查，4例行CT检查，3例行MR检查。结果 6例骨梗死共累及10个部位，股骨下段4个，胫骨上段4个，胫骨下段1个，股骨颈及粗隆部1个。其中2个部位经手术病理证实，平片均显示髓腔内不均匀性骨化。CT显示髓腔内呈地图样改变，周围环以硬化边。MRI显示病变的组成分为3部分，中心是完全坏死的骨髓和骨组织，外围是部分坏死的骨髓和骨组织，再外边是充血区及正常骨组织。1例于骺早闭的上方发现骨梗死，根据骨折愈合动物实验研究，认为是静脉窦栓塞所致。结论 MRI是检查诊断早期骨梗死最为有效的方法，可以发现早期病变。X线平片对于中晚期病变有帮助，CT较平片敏感，骨梗死的诊断最好采用MRI、CT以及平片相结合。

Image and pathology of the bone infarct

Objective To investigate the progressing of pathology and the characteristic findings on plain radiography,CT and MR imaging of the bone infarct.Methods Five out of 6 patients were examined by plain radiography,four by CT,and three by MRI. Results Ten sites of the bone infarct in 6 patients were found,including 4 in the distal femur,4 in the proximal tibia,1 in the distal tibia,and 1 in the femoral neck and tuberosity.The lesion sites in 2 patients were confirmed by operation and pathology.Plain radiography manifestation was inhomogeneous ossification in the intramedullary cavity.CT manifestation was "map-shaped" lesions with the surrounding sclerotic rim in the intramedullary cavity.MRI showed that the lesions consisted of three zones,the center was the necrotic tissues of the bone and bone marrow,the surrounding part was the partially necrotic tissues of the bone and bone marrow,and the outer most part was the reactive bone tissue and the granulation tissue.The bone infarct occurred in the metaphysis of the right distal tibia associated with the premature epiphyseal closure in one patient.According to the animal fracture-healing experiments preceding,we speculated that the bone infarct resulted from the venous sinus obstruction.Conclusion MRI is the most effective way to examine and find the bone infarct in the early stags.Plain radiography was helpful to diagnose the bone infarct in the middle and later stages.CT examination is more sensitive than plain radiography.Plain radiography,CT and MR imaging should be combined in diagnosing the bone infarct.