腰椎间盘碎片在前硬膜囊外间隙中游走路径的MRI观察

MRI observation of migration paths of disk fragment in the anterior epidural space

目的 观察前硬膜囊外间隙 (AES)椎间盘碎片的游走路径。方法 搜集经手术证实的18例腰椎间盘髓核脱出 (HNP) ,进行MRI回顾分析。结果 在椎管内 ,当碎片从供体间盘脱出游走时 ,向上 12例 ,向下 6例。 10例占据右隔区 ,8例占据左隔区。碎片经常被限制在AES左半区和右半区 ,很少位于中线。在矢状面 ,T2 WI显示碎片为低或等信号压迫硬膜囊 ,T1WI显示碎片为等信号并压迫后纵韧带 (PLL)、脊髓。在轴面 ,T2 WI显示碎片压迫中线隔、后纵韧带、硬膜囊。脂肪抑制扫描显示碎片信号增高。结论 间盘碎片游走路径由AES的解剖决定。抑脂扫描有临床诊断意义。

Objective To observe the migration paths of disk fragment in the anterior epidural space (AES). Methods Eighteen operation-proved cases with herniated nucleus pulposus of lumbar disk were collected and the MR findings were retrospectively reviewed. Results The disk fragments moved in a superior (12 cases,67%) or inferior (6 cases,33%) direction from the donor disk. 10 cases occurred in right septum and 8 cases in left septum. The displaced disk components were most frequently dislodged into the right or left AES, and rarely straddled the midline. On sagittal T 2WI, fragments exhibited low or intermediate signal intensity and compressed the dura mater of spinal cord. On T 1WI, fragments exhibited intermediate signal intensity and compressed the PLL and the spinal cord. On axial T 2WI, fragments exhibited compression of the PLL, the midline septum, and the dura mater of spinal cord. On fat-suppression scan, fragments exhibited increased signal intensity. Conclusion The migrating path of a disk fragment is determined by the anatomy of the AES. Fat-suppression scan has a clinical diagnostic significance.