股骨头坏死的MRI、CT与病理表现对照研究

目的对比分析股骨头坏死（FHN）的MRI、CT与病理学表现，研究其三者的对应关系。方法分析50例76髋FHN患者同期检查的髋关节MRI和CT资料，二者检查时间间隔少于7d。另将其中6例髋关节置换下的坏死股骨头标本行CT扫描后制成相应厚度的切片，参照标本CT图像在标本切片上相应区域多点取材进行病理学观察。结果76个股骨头内均出现T1WI和T2WI低信号带，相应CT上72个髋关节表现为硬化带，4个髋关节表现正常。CT硬化带病理主要为粗大骨小梁、纤维肉芽组织和大量成骨，其内侧伴行低密度带病理主要为大量纤维肉芽组织和少量新生骨，其包绕区病理上主要为骨小梁和骨髓全部坏死，其远侧外围区为正常骨质和骨髓结构，可伴骨髓间质水肿改变。结论FHN的MRI低信号带和CT硬化带相互对应，为骨坏死一存活交界区，一定程度上反映骨坏死后修复过程，是FHN特异性的征象。

Comparative study of CT,MRI and pathological findings on the femoral head necrosis

Objective To compare the manifestations of MRI, CT and pathology of femoral head necrosis （FHN） and to confirm the correspondence between them. Methods The imaging findings of 50 patients （76 hips） with FHN proved by follow-up studies or pathology were analyzed. All patients underwent MRI and CT at the same period （the time interval of two examinations less than 7d）. 6 replaced femoral head specimens of FHN were examined with CT scanner and then sawed into slices corresponding with image slices. According to CT signs of the femoral head samples, a lot of samples from the slices were drawn for pathological examination. Results Low-signal hne-like sign appeared both on T1WI and T2WI in 76 affected hips, which corresponded to the blurred high-density sclerosis band on CT in 72 hips, except for 4 normal hips. Under microscope, thicken trabecula and new bone formation were showed with inflammatory granulation tissue between trabecula in high-density sclerosis band. A great quantity of inflammatory granulation tissue and some bone formation were displayed in inner band of low density, Necrotic trabeeula and necrotic bone marrow appeared in the area surrounded by high-density band. The normal structure of bone and bone marrow were shown outside high-density sclerosis band, some with a little bone marrow stromal edema. Conclusion Low-signal line-like sign on MRI corresponding to the high-density sclerosis band on CT represents the junction area between bone necrosis and survival, which to some extent reflects the repair process of bone necrosis and is a specific diagnostic sign of FHN.