椎管闭合不全的MRI诊断(附27例分析)

目的:分析椎管闭合不全的MRI表现特点,评价MRI诊断和鉴别诊断的价值。方法:回顾性分析27例椎管闭合不全的MRI资料,经手术证实9例,MR表现典型18例。结果:MRI显示偏侧脊髓脊膜膨出1例,腰段椎管后裂开,脊髓裂开,左侧脊髓脊膜向后膨出。脊髓纵裂2例,脊髓硬膜囊被骨性或纤维间隔分开。脂肪脊髓裂5例,骶管裂开且皮下脂肪突入椎管内,脂肪瘤—基板界面位于骶管内。脂肪脊髓脊膜膨出2例,腰骶管后裂开且腰骶皮下脂肪瘤通过裂口疝入硬膜下,横断位见脂肪瘤—基板界面位于骶管外。脊膜膨出6例,腰骶背部皮下囊状突出物与蛛网膜下腔脑脊液相通。硬膜下脂肪瘤4例,硬膜下病变在T1WI及T2WI上呈高信号。终丝脂肪瘤4例,T1加权像上见终丝结节状、线条状脂肪信号。椎管内畸胎瘤2例,硬膜囊内不均匀信号团块状占位。骶管内脊膜囊肿1例,骶管内椭圆形在T1WI呈低信号,T2WI呈高信号影。结论:每型椎管闭合不全有相应的MRI表现特点,大多数MRI可准确诊断。

MRI diagnosis of spinal dysraphism (analysis of 27 cases)

Objective:To analyze MRI features of spinal dysraphism in confirming MR diagnosis to it.Methods:To study MRI imagings of 27 spinal dysraphisms retrospectively.9 cases were proved by operation and 18 cases were shown typically MR imagings.Results:MR imaging features were as follow:In 1 case with hemimyelomeningocele,lumbar spinal bifida,focal spinal cord was split and the left half was myelomeningocele.In 2 cases with split cord malformation,spinal cord or dural sac were separated by bony or fibrous septum.In 5 cases with lipomyeloschisis,subcutaneous lipoma projected into sacral canal which was bifida,lipoma/placode interface located into sacral canal.In 2 cases with lipomyelomeningocele,lumbar sacral spine bifida and subcutaneous lipoma of lumbar sacral herniated into subdural,lipoma/placode interface located outside sacral canal.In 6 cases with meningocele,lumbosacral dorsal subcutaneous cystic mass connecting with subararchnoid space.In 4 cases with intradural lipoma,subdural lesion with high signal on T_1WI and T_2WI.In 4 cases with lipoma of filum terminale,on T_1WI filum terminal had nodular or stringed lipoma signal.In 2 cases with spine canal teratoma,heterogeneous signal mass in the dural sac.In 1 case with spinal meningeal cyst,ovoid cyst with low signal on T_1WI and high signal on T_2WI in the sacral canal.Conclusion:Each type of spinal dysraphism had its corresponding MRI features,MRI could diagnosis most of them precisely.