Ⅰ型神经纤维瘤病伴脊柱侧凸患者肋骨头脱入椎管的影像学特征

The radiological features of rib head protrusion into the spinal canal in patients with scoliosis secondary to neurofibromatosis type 1

中文关键词:  神经纤维瘤病  脊柱侧凸  肋骨头  脱位  影像学特征

英文关键词:Neurofibromatosis  Scoliosis  Rib head  Dislocation  Imaging

中文摘要:

  【摘要】 目的：探讨Ⅰ型神经纤维瘤病伴脊柱侧凸（scoliosis secondary to neurofibromatosis type 1，NF-1S）患者肋骨头脱入椎管内的影像学特征。方法：对我院1998年8月~2011年3月脊柱外科收治的142例NF-1S患者的资料进行回顾性分析，有完整影像学检查的胸弯患者共91例，其中11例患者伴有肋骨头脱入椎管，男性7例，女性4例，年龄11~21岁。测量肋骨进入椎管内程度、顶椎旋转程度和双侧肋骨头宽度比，总结其影像学特征，并分析其发生的原因。结果：NF-1S患者肋骨头脱入椎管内现象的发生率为12.1%。肋骨头脱入椎管均发生在脊柱侧凸的凸侧顶椎区。脱入水平位于T5～T11。肋骨进入椎管内程度为11.2%～50%，平均26.5%。脱入椎管内的肋骨头形态尖而细长，其宽度与对侧肋骨头宽度的比值为0.50～0.99，平均0.77；均伴有显著顶椎旋转（Nash-Moe法Ⅰ～Ⅳ度，中位数为Ⅲ度）。在MRI轴面成像上脊髓向凹侧偏移，其中5例患者脊髓紧贴凹侧椎弓根，4例伴有椎旁肿瘤。结论：NF-1S患者肋骨头脱入椎管发生在脊柱侧凸的凸侧顶椎区。肋骨头尖锐细长、椎体旋转半脱位可能是肋骨头脱入椎管内的重要原因。需手术治疗的NF-1S患者术前均应行顶椎区CT检查。

英文摘要:

  【Abstract】 Objectives:　To investigate the radiological features of the protrusion of rib head into the spinal canal in patients with scoliosis secondary to neurofibromatosis type 1(NF-1S). Methods:　From August 1998 to March 2011, 142 patients with NF-1S were included in this study. Ninety-one patients with thoracic scoliosis had complete imaging data. Seven boys and four girls with the age ranged from 11 to 21 years old were found rib head protruded into the spinal canal. The magnitude of rib head protrusion into spinal canal, the apex rotation and the ratio of the displaced rib head width between convex and concave side were measured. The features of this phenomenon were concluded and the cause was analyzed. Results: The incidence of this phenomenon was 12.1%. The level of rib head protrusion was from T5 to T11 vertebra. The magnitude of rib head protrusion into the canal was from 11.2% to 50% with an average magnitude of 26.5%. The rib head into the canal behaved sharp and thin. The ratio of the displaced rib head width between convex and concave side was 0.50 to 0.99 with an average ratio of 0.77. The apex where the rib head protruded into the canal rotated significantly and the median of rotation was degree Ⅲ(Ⅰ to Ⅳ degrees). In the axial imaging in MRI, the spinal cord shifted to the concave side. The spinal cord against the medial wall of spinal pedicle in the concave side was found in 5 patients. Paraspinal neurofibromas were found in 4 patients. Conclusions: The rib head protrusion into the spinal canal is found in the convex side of apical area in the patients with NF-1S. The sharpness and thinness of rib, rotation and displacement of apex may contribute to this. CT-scan is a necessary examination around apical area before operation.