激素性兔股骨头缺血性坏死模型的实验研究

The experimental research on rabbit models of corticosteroid-induced avascular necrosis of femoral head

目的探讨激素性股骨头坏死(ANFH)的病理发展过程及早期影像学表现。方法运用ANFH模型25只,随机(数字法)分为5组,与对照组进行比较,分别观察注射4、6、8、10、12周股骨头病理组织学和影像学改变。结果ANFH最早变化发生在骨髓,然后为骨小梁。在给药4、6、8、10、12周时,数字X线摄影(DR)检查分别有0、0、0、2、2只兔股骨头可见斑片状密度减低影;CT分别有0、0、1、2、4只兔股骨头可见囊状透亮区和斑片状密度减低影;MRI分别有0、3、5、5、5只兔股骨头在T1WI呈不规则低信号,T2WI呈低信号或高信号。结论ANFH的影像学表现与病理变化密切相关,MRI是诊断ANFH最敏感的方法。

Objective To study the pathological progression and early imaging diagnosis of corticosteroid-induced avascular necrosis of the femoral head (ANFH). Methods Twenty-five adult rabbits with corticosteroid-induced ANFH were studied, and pathogenic histology and the imaging changes of the test group were observed at 4 weeks, 6 weeks, 8 weeks, 10 weeks, and 12 weeks, respectively, after the injection, and compared with the control group. Results The initial changes happened in the marrow, then bone trabeculae. At 4 weeks, 6 weeks, 8 weeks, 10 weeks, and 12 weeks after the injection of corticosteroid, low-density patchy shadows could be seen in DR in 0, 0, 0, 2, and 2 rabbits, respectively. Radiolucent cystic areas and low density patchy shadows could be detected on CT scans in 0, 0, 1, 2, and 4 rabbits accordingly, while MRI findings showed irregular low signal on T_1-weighted images and irregular low or high signal on T_2-weighted images in 0, 3, 5, 5, and 5 rabbits, respectively. Conclusion Imaging manifestation of ANFH is closely related to the pathological changes. MRI is the most sensitive approach to early detection of ANFH.