股骨头缺血性坏死的CT与MRI对照分析

The comparative study of CT and MRI on femoral head necrosis

目的对比股骨头缺血坏死的CT和MRI征象并探讨其相应的病理基础。方法分析和总结18例30髋随访和病理证实的股骨头坏死的CT和MRI影像学资料。结果28髋CT上的粗细不均、凹凸不平、边界较模糊的高密度硬化线均与MRI相应部位的"线样征"对应,另2髋MRI上出现"线样征"而CT仅表现斑点状硬化。CT上高密度硬化线围绕的病变区表现正常者26髋,分别对应MRI"线样征"包绕区脂肪样信号者12髋和混杂信号者14髋;4髋骨小梁模糊与MRI"线样征"包绕区混杂信号者对应。结论CT上高密度硬化线与MRI上"线样征"相对应,是坏死区和正常存活区的反应界面,均可作为诊断股骨头缺血坏死的特异性征象,但MRI较CT能够准确反映不同修复时期的病理变化过程。

Objective To compare the imaging features of CT and MRI in the femoral head necrosis as well as their pathological basis. Methods 18 cases （30 hips） with femoral head necrosis proved by follow-up studies or pathology were analyzed, including 3 cases of pathological data. Results The blurred high-density sclerotic line on CT in 28 hips were corresponded to ＂line-like signs＂ on MRI, whereas, the other two hips without blurred high-density sclerosis line appeared ＂line-like signs＂ on MRI. The normal area surrounded by the high-density line on CT in 26 hips were corresponded to fat-like signal area in 12 hips and mixed signal area in 14 hips on MRI. The other 4 hips with blurred bony trabeculum surrounded by the high-density line on CT showed mixed signal intensity on MRI. Conclusion The high-density sclerotic line on CT corresponds to ＂line-like sign＂ on MRI, which was considered as reactive interface between necrotic and viable region, was a specific signs to diagnose FHN. Compared with CT, MRI can accurately reflect pathological process during different repaired stages.