长骨转移瘤的影像学诊断

The imaging diagnosis of metastatic tumor in long bone

目的探讨长骨转移瘤的影像学特点,提高诊断准确率。方法选择具有明确原发病史或病理证实的45例长骨转移瘤患者为研究对象,对其骨转移瘤病灶的X线、CT和MRI影像表现进行回顾性总结及分析。其中X线检查18例,CT检查26例,MR检查18例(部分患者同时做2种或3种检查)。结果 X线发现20处病灶的基本特点为呈不规则形、多发斑点虫蚀样破坏或类椭圆形透亮区。无论累及骨端还是累及骨干病变,均伴有周围骨质破坏,并部分相邻皮质伴有不连续条带状骨膜增生。CT发现27处病灶均呈溶骨性骨质破坏,破坏范围可单侧或四周,部分周围形成软组织肿块。累及骨干分为皮质型和常见型。MRI发现20处病灶表现为长T1长T2、压脂像为高信号。结论长骨转移瘤在影像学表现上具有多样化特点,具体在X线、CT、MRI表现各自具有其特征性。相对而言CT、MRI在敏感性方面显示出较显著优势,尤其是MRI在发现早期髓腔病变具有较高敏感性。但X线检查在骨膜反应方面则优于其他检查。若将X线、CT和MRI三者相结合进行综合分析验证,对于诊断长骨转移瘤和与骨其他病变相鉴别具有显著意义,可提高诊断准确率。

Objective To discuss the image characteristics of metastatic tumor in long bones and to improve diagnostic accuracy.Methods Forty-five patients suffered from metastasis tumor in long bones with identified tumor history or certified by pathology were involved.Imaging performance of bone metastasis in these cases,including X-ray（18 cases）,computed tomography（CT）（26 cases）and magnetic resonance imaging（MRI）（18 cases）,were analyzed retrospectively.Results The images of 20 lesions detected by X-ray were irregular changes,multiple spots moth-eaten destruction or oval radiolucent area.In these cases,bony destruction and discrete stripped periosteum hyperplasia appeared whether in epiphysis or diaphysis.While,the features of 27 cases by CT presented destruction in one side or around the bone,parts of which formed soft tissue mass.The cases detected by CT,which involved diaphysis,could be divided into cortical type and common type.20 cases metastatic tumor of bone showed long T1 and long T2 signals on MRI,with hyperintense on fat-suppressed images.Conclusion The imaging performance of metastatic tumor in long bones showed diverse characteristics,and it displayed characteristic features on X-ray,CT and MRI.In this study,CT and MRI showed more sensitive comparatively,especially on early detection about medullary cavity lesions with MRI.But X-ray exhibited advantage on periosteal reaction compared to the other methods.It will be more meaningful and accurate on diagnosis and differentiation of metastatic tumor in long bones if these three imaging methods are combinated with each other.