肝泡型包虫病骨转移的影像特征

The imaging features of osseous metastasis of hepatic alveolar hydatida

目的 探讨肝泡型包虫病骨转移影像特点，以提高影像诊断水平。方法 回顾性分析青海大学附属医院2013年1月至2017年5月，经临床及影像诊断的14例肝泡型包虫病骨转移的CT、MRI影像特点。其中男8例，女6例；年龄15~72岁，中位年龄41岁；6例行CT平扫及三维重建，1例行MRI常规平扫；7例同时行CT、MRI扫描（CT增强2例、MRI增强3例、DWI扫描1例）。结果 14例中脊柱转移10例，其中连续3个椎体受累6例、2个椎体受累2例、1个椎体受累2例，相应附件受累且病灶周围形成不规则软组织包块9例，邻近胸肋关节受累6例；CT检查显示椎体呈地图样、溶骨性骨质破坏、硬化；附件呈膨胀性骨质破坏，其中7例软组织包块内见囊状水样密度影、囊壁弧形钙化或不规则钙化，2例增强扫描软组织包块未见强化；MRI主要表现为病变椎体及周围软组织包块呈高低混杂信号，6例病灶T1WI、T2WI均可见低信号的骨质硬化影和不规则或弧形钙化影；6例相应附件及邻近肋骨受累；4例病灶内见散在＂小囊泡＂状T2WI高信号影。右侧肩峰、肋骨、肋软骨及骨盆转移各1例，CT表现同脊柱病灶，破坏区或周围见囊样密度影，其内见斑点状钙化；MRI显示肋骨、骨盆均为溶骨性、膨胀性骨质破坏，邻近髓腔内见T1WI、T2WI低信号影，周围见囊状T2WI高信号影。合并肺转移5例，合并腹膜后转移6例。结论 肝泡型包虫病骨转移病灶影像上呈地图样、溶骨性骨质破坏，破坏区周围骨质增生硬化，或形成软组织包块。软组织包块内可见囊状或＂小囊泡＂状水样密度影及弧线状钙化。这些特征有助于肝泡型包虫病骨转移的诊断。

Objective To investigate the CT and MR imaging feature of osseous metastasis of hepatic alveolar hydatida.Methods CT and MR imaging features of osseous metastasis of hepatic alveolar hydatid were retrospectively analyzed in 14 cases confirmed by clinic and radiology.Results Of the 10 vertebral metastasises, three vertebral bodies were involved in 6 cases, two adjacent vertebral bodies were involved in 2 cases, single vertebral body was involved in 1 case, corresponding vertebral accessory was involved in 9 cases, irregular mass was formed in paravertebral muscles with ill-defined margins in 9 cases, adjacent ribs were involved in 6 cases. On CT scans, the lesions of vertebral body showed osteolytic and geographical bone destruction with bone sclerosis. The lesions of vertebral accessory showed swelling and osteolytic bone destruction, small cystic density and calcification of cystic wall and irregular calcification were found in 7 cases. The lesions of scapula, costal cartilage, ribs and pelvis showed swelling and osteolytic bone destruction, and bone sclerosis, and revealed cystic density with calcified speckles. On MR scans, the lesions of vertebral body and paravertebral muscles showed high and low mixed signal, with hypointensity on T1WI and T2WI, vertebral accessory and adjacent ribs were involved in 6 cases. Small cyst with T2 hyperintensity was found in 4 cases. The lesions of ribs and pelvis showed swelling and osteolytic bone destruction and adjacent medullary appeared hypointensity on T1WI and T2WI, cystic signal of T2 hyperintensity was identified. There were 5 cases of pulmonary metastasis and 6 cases of retroperitoneal metastasis.Conclusion Imaging features of osteolytic, geographical bone destruction with bone sclerosis, small cystic density or cystic signal and calcified speckles or arc calcification in mass are helpful for the diagnosis of osseous metastasis of hepatic alveolar hydatid.