原发性及继发性动脉瘤样骨囊肿的影像学诊断

Imaging Diagnosis of Primary and Secondary Aneurysmal Bone Cyst

目的:分析原发性及继发性动脉瘤样骨囊肿(ABC)的影像学表现,评价其影像学诊断价值。材料和方法:回顾性分析经手术或活检证实的动脉瘤样骨囊肿176例,其中原发性动脉瘤样骨囊肿111例,继发性动脉瘤样骨囊肿65例。完整影像学资料共42例,均行X线检查,其中30例行CT检查,15例行MRI检查,9例同时行CT及MRI检查。结果:42例动脉瘤样骨囊肿平片上根据病变部位分偏心型22例、髓内型18例、骨旁型2例,大多数表现为偏心型膨胀性骨破坏;CT扫描可见25例不同程度骨膨胀、骨皮质内缘的分房状压迹和骨嵴影,皮质破坏断缺7例,15例见骨包壳,3例见液-液平面;15例MRI扫描表现为分叶状肿块,9例MRI表现为T1WI低、T2WI高信号囊腔,6例表现为混杂信号,囊间隔均为T1WI、T2WI低信号,6例行MRI增强扫描,均见间隔强化,5例见液-液平面。结论:原发性及继发性动脉瘤样骨囊肿具有一定的影像学特征,X线、CT及MRI三者结合能明显提高诊断正确率。

Purpose： To analyze imaging characteristics of primary and secondary aneurysmal bone cyst （ABC） and to evaluate the value of its imaging diagnosis. Materials and Methods： The characteristics of X - ray CT and MRI of the 176 cases＇ aneurysmal bone cyst confirmed by operation or puncture were analysed retrospectively. The 111 cases were primary aneurysmal bone cyst and 65 cases were secondary aneurysmal bone cyst. 42 cases have complete imaging information and all of 42 cases were undergone X - ray examination, 30 cases were imaged by CT and 15 cases by MRI. 9 cases were examined by both CT and MRI. Results： On X - ray imaging of 42 cases＇ aneurysmal bone cyst , the lesions were divided into 22 cases of off- center, 18 cases of medulla and 2 cases of subperiosteum. The appearances of most lesion were expandiy eccentric bony destruction. On CT imaging, 25 cases were expansive bony destruction of different degree. We found that impression as lobulation and bone trabeculae. Fracture of bone shells were discovered by 7 cases. Thin osseous layer were found by 15 cases. Liqued - liqued level were discovered by 3 cases. The presence of lobulations of tumor were discovered by MR imaging of 15 cases. On MR imaging we found bulk region full of fluid that was low signal on the T1WI and high signal on the T2WI in 9 cases and miscellaneous signals in 6 cases. The septation that have low signals both in the T1 WI and T2WI can be seen. On enhancement scanning of 6 cases, the septation in the diseased region distinctly enhanced. Liquedliqued level were discovered by 5 cases.Conclusion： The primary and secondary aneurysmal bone cysts have some identical imaging characteristics , combination of X - ray CT and MRI can distinctly improve the correct ratio of the diagnosis.