原发性与继发性动脉瘤样骨囊肿的MRI表现及MRI诊断价值

The MRI manifestations and diagnostic value in primary and secondary aneurysmal bone cyst

目的:分析动脉瘤样骨囊肿的MRI表现,评价其影像学诊断价值。方法:回顾性分析18例经手术病理证实的原发性及继发性动脉瘤样骨囊肿的MRI表现,并进行文献复习。结果:18例病灶均表现为膨胀性溶骨性骨质破坏(100%),15例位于长骨(83.3%),12例为偏心型(66.7%)。其中11例见骨皮质破坏(66.1%),2例见骨膜反应(11.1%),12例边缘见分叶(66.7%),14例见囊腔(77.8%),10例见囊间隔(55.6%),11例见低信号边界(61.1%),6例见液-液平面(33.3%),5例见软组织肿块(27.8%)。结论:①原发性动脉瘤样骨囊肿MRI表现较一致;继发性动脉瘤样骨囊肿表现复杂多样,但多数仍具有动脉瘤样骨囊肿的MRI共性特点,如囊腔及低信号边界等。②MRI有助于动脉瘤样骨囊肿尤其是继发性动脉瘤样骨囊肿的定性诊断,较X线及CT能更早、更敏感地显示动脉瘤样骨囊肿的特征性表现。③综合X线、CT及MRI进行影像学分析有助于提高诊断准确率。

Objective： To analyze the MRI manifestations of aneurysmal bone cyst and to evaluate the value of its imaging diagnosis. Methods： A retrospective analysis was made on MR images of 18 patients who were pathologically proved to have primary or secondary aneurysmal bone cyst. Results： Eighteen lesions all showed expansile and lytic bony destruction （100%）, and 15 lesions located in long tubular bones （83.3%）, and 12 lesions were eccentric （66.7%）. Among all the lesions, there were visible cortical bone defect in 11 lesions（66.1%）, periosteal reaction in 2 lesions（11.1%）, lobulated margin in 12 lesions（66.7%）, multiple cystic spaces in 14 lesions（77.8%）, internal septations in 10 lesions（55.6%）, hypointense peripheral rim in 11 lesions（61.1%）, fluid-fluid levels in 6 lesions（33.3%）, soft tissue masses in 5 lesions（27.8%）. Conclusion： ①Primary aneurysmal bone cyst showed relatively uniform MRI manifestations. Secondary aneurysmal bone cyst showed complicate and multiplex manifestations, however, most lesions showed collective MRI characters of aneurysmal bone cyst such as multiple cystic spaces and hypointense rims. ②MRI could reveal characteristic manifestations earlier and more sensitive than X-ray and CT. It is helpful to qualitative diagnosis of aneurysmal bone cyst, especially to secondary aneurysmal bone cyst. ③A comprehensive imaging analysis could improve diagnostic accuracy of aneurysmal bone cyst.