椎管内恶性神经鞘膜瘤CT和MRI成像特征

CT and MRI imaging features of intraspinal malignant neurilemmoma

目的探讨椎管内恶性神经鞘膜瘤CT和MRI成像特征。方法选取2017年5月至2018年3月间湖北省应城市人民医院收治的经手术病理证实的52例椎管内恶性神经鞘膜瘤患者作为研究对象。所有患者均行CT和MRI平扫及增强检查,观察并分析椎管内恶性神经鞘膜瘤患者CT和MRI成像特征。结果 52例患者的CT平扫显示椎体层面椎管内软组织密度影,分布不均,内部多见斑片状低密度影,7例患者表现为溶骨性骨质破坏,45例患者病变邻近椎管骨质皆呈不同程度的浸润性骨质破坏;其中39例患者骨质破坏边缘较糙,局部出现骨质硬化,13例患者骨质破坏较小,但局部伴随浸润性骨质破坏,破坏边缘较整齐;且患者伴有扩大水平椎间孔。39例患者行MRI平扫,均出现相应椎管内T_1WI低信号、T_2WI高低混合信号,且在病变部位出现分布不均斑片样T_1WI低信号和T_2WI高信号;浸润分布在以椎管为中心向邻近椎体、附件区、竖脊肌及其周围脂肪间隙等;增强扫描发现分布不匀增强。CT检查中有11例患者确诊,CT准确率为63. 5%(33/52),误诊率为25. 0%(13/52),漏诊率为11. 5%(6/52); MRI检查中有12例患者确诊,MRI准确率为87. 2%(34/39),误诊率为10. 3%(4/39),漏诊率为2. 6%(1/39)。MRI诊断准确率明显高于CT诊断,差异有统计学意义(P <0. 05)。结论不规则或浅分叶状肿块跨2个椎体以上、包绕脊神经且椎间孔扩大、浸润性骨质破坏、周围肌肉脂肪浸润、CT密度及MRI信号不匀和分布不匀增强是椎管内恶性神经鞘膜瘤典型影像学特征。

Objective To investigate the CT and MRI imaging features of intraspinal malignant neurilemmoma.Methods A total of 52 patients diagnosed with intraspinal malignant neurilemmoma comfirmed by surgery and pathology at Yingcheng People's Hospital between May 2017 and March 2018 were selected to the study subjects.Non-enhanced and enhanced CT&MRI scan examinations were performed on all the patients,and CT and MRI imaging features were observed and analyzed.Results The distribution was uneven for intraspinal soft tissue density in 52 patients who underwent non-enhanced CT scan with patchy low density shadow inside.Intraspinal bone destruction was found in 2 patients.Osteolytic bone destruction was found in 7 patients.A total of,45 patients were found with lesions near the spinal canal bone showing various degrees of invasive bone destruction.Among them,39 patients had rough bone destruction edge and localized bone sclerosis,as well as 13 had small bone destruction and localized infiltration bone destruction in neat bone edge,accompanied by enlarged horizontal intervertebral foramen.On the other hand,mixed signals of T1WI low signal and T2WI high&low in the spinal canal were found in 39 patients who underwent normal MRI scan.The uneven distribution of patchy T1WI low signal and T2WI high signal appeared in the lesion.The infiltration was distributed in the spinal canal,adjacent to vertebral body,the attachment area,the erector spinae muscle and its surrounding fat gap,etc..Enhanced scanning revealed uneven distribution.Eleven patients were diagnosed by CT.The accuracy of CT was 63.5%(33/52),the rate of misdiagnosis was 25.0%(13/52),and the rate of missed diagnosis was 11.5%(6/52).Twelve patients were diagnosed by MRI.The accuracy of MRI was 87.2%(34/39),the rate of misdiagnosis was 10.3%(4/39),and the rate of missed diagnosis was 2.6%(1/39).The diagnostic accuracy of MRI was significantly higher than that of CT,and the difference was statistically significant(P<0.05).Conclusion Irregular or shallow lobulated lumps over the 2 vertebral bodies,the surrounded spinal nerve and intervertebral foramen enlarging,invasive bone destruction and peripheral muscle fat infiltration,CT density and MRI signal unevenness,and uneven distribution enlargement are the typical imaging features of intraspinal malignant neurilemmoma.