早期股骨头缺血性坏死影像模型的实验研究  

The Imaging Pattern of Early Avascular Necrosis of the Femoral Head: An Experimental Study

作　　者：宋英儒[1] 黄仲奎[1] 龙莉玲[1] 苏伟[2] 江峰[2] 蒋一强[3] 覃伟武[4] 

机构地区：[1]广西医科大学第一附属医院放射科,南宁530027 [2]广西医科大学第一附属医院骨科,南宁530027 [3]广西医科大学第一附属医院病理科,南宁530027 [4]广西医科大学第一附属医院ECT科,南宁530027

出　　处：《临床放射学杂志》2002年第5期392-396,共5页Journal of Clinical Radiology

摘　　要：目的　探讨动物早期股骨头缺血性坏死 (ANFH)的影像表现及病理基础 ,为临床诊断提供依据。材料与方法　选择 18只自然放养的健康山羊 (雌雄、年龄不限 )制成股骨头坏死模型。正常对照组为同体未手术侧股骨头。术后 1、2、3、4、5、7、12周分别作MRI、X线、CT检查。在影像检查完毕后 ,立即取出双侧股骨头 ,用肉眼观察、对比外表后以光学显微镜进行病理观察。结果　X线、CT检查 7周以前均无阳性表现 ;12周X线检查 3只仅 1只见密度稍降低 ,而CT检查 3只密度均较明显降低。MRI于 1周检查 9只中 6只出现信号异常。 3～ 12周所检查的山羊MRI信号均出现异常 ,12周以前所有检查均未见股骨头外形改变。病理变化是 1～ 2周单纯骨髓局灶性溶解 ,骨小梁间出现不定形细胞碎片及肉芽组织形成 ,脂肪组织未或刚开始液化 ;3～ 7周骨髓继续坏死并纤维组织增生 ;12周骨髓坏死停止并开始出现新骨。早期ANFH的 3种影像学检查以MRI最敏感。结论　X线和CT在 7周前不能反映股骨头缺血坏死的病理变化 ,12周后因骨细胞大量坏死、脱钙才发现有轻微的骨密度降低和骨小梁结构紊乱等 ,故其敏感性差。早期ANFH的影像检查X线和CT的意义不大。MRI检查在 1周开始即可检出异常信号改变 ,其敏感性较高。早期ANFH的影像检查首选MRI。Objective To study the imaging signs and the pathological basis of early avascular necrosis of the femoral head (ANFH) in animal models.Materials and Methods ANFH model was prepared in 18 healthy naturally bred goats, regardless of the sex and age. The un operated femoral heads were taken as control group. MRI CT and radiography were performed at 1, 2, 3, 4, 5, 7 and 12 weeks after the procedure. The animals were sacrificed immediately after the last examination. Both femoral heads were removed and macroscopic and microscopic observations were made.Results No abnormal findings were seen on CT and radiographs in 7 weeks after the procedure. In experimental group at 12 weeks, decreased density was seen in one of 3 femoral heads on radiographs, while in all 3 heads on CT scans. MRI demonstrated abnormal signal in 6 of 9 heads during the first week. During 3～12 weeks, abnormal MR signals were seen in all diseased heads. Before 12 weeks, no any change in shape was found in all imaging examinations. Pathologically, focal dissolution of the marrow, cell fragments in bone trabeculae, granulation, or liquefaction of the fat occurred within 1～2 weeks. Marrow necrosis kept going with fibrous hyperplasia during 3～7 weeks until 12 weeks when the necrosis stopped and the new bone formation occurred. MRI was the most sensitive technique in detecting early changes of ANFH.Conclusion In this experiment, the radiography and CT can not demonstrate the early pathologic changes of ANFH within 7 weeks after the surgery. Only after 12 weeks, slight decreased bone density and trabecular derangement due to marrow necrosis and decalcification can be observed. Thus, radiography and CT is of little value in detecting early changes of ANFH. In contrast, MRI is very sensitive, the abnormal signals can be detected as early as in the first week, thus, MRI is of the choice for early ANFH.

关 键 词：早期肌骨头缺血性坏死影像模型 早期股骨头缺血性坏死 影像诊断 动物实验 影像学表现 

分 类 号：R816.8[医药卫生—放射医学]