椎管内肠源性囊肿的磁共振影像诊断

MR Imaging of Intraspinal Enterogenous Cysts

目的：研究椎管内肠源性囊肿的磁共振影像学特征。材料和方法：收集了１９例经手术和病理证实的椎管内肠源性囊肿的资料，分析其磁共振影像表现。结果：１９例椎管内肠源性囊肿中，位于硬膜下１８例，位于硬膜外１例。病变最常见部位是胸段椎管内（４７％），其次为颈段（３７％）和颅椎结合部（１６％）；１８例（９５％）囊肿位于中线部位脊髓腹侧面；１０例肠源性囊肿患者同时伴有脊柱的其它畸形。１９例肠源性囊肿的磁共振影像表现包括：Ｔ如加权像上为脑脊液信号强度影５例，稍高于脑脊液信号强度影１３柳，与脊髓信号强度近似者１例：Ｔ２加权像时，７例囊肿信号强度等于脑脊液信号强度，２例稍高于脑脊液信号强度。所有囊肿的壁均光滑，囊内信号均匀。１５例在磁共振横断面图像上见囊肿部分或大部分被镶嵌在脊髓中。结论：磁共振影像可以清楚地显示肠源性囊肿的全貌，当在脊髓腹侧面中线部位硬膜下腔发现一边缘光滑的囊肿，其Ｔ１和Ｔ２加权像上信号强度等于或高于脑脊液并伴有其它脊柱畸形时，应高度提示肠源性囊肿的诊断。

To delineate the MR imaging features of intraspinal enterogenous cysts.Materials and Methods:Nineteen cases of surgically-proven enterogenous cysts were reviewed and their MR imaging features characterized. Results : Eighteen intradural cysts and one completely extradural cyst were found in the spinal cannal.The most common location was in the thoracic spine (47%),with cervical spine (37%) and craniovenebral junction (16%). Eighteen cysts (95%) were located in the midline. All of the midline cysts were anterior to the spinal cord. Vertebral anomalies or associated cleft were seen in only 53 % (10/19)of cases. MR scan were performed in all cases; 18 cysts were either isointense (5/18) or slightly hyperintense (13/18) compared to CSF on T1 WI.In one case the cyst was isointense with spinal cord, Of 19 cases, 9 had T2WI. In all but two the cysts were isointense to CSF,2/9 were hyperintense with CSF,In fifteen cases the cysts were almost embedded in the spinal cord with the interface between cyst and cord appearing acutely angle on axial T1 WI.Conclusion:Enterogenous cysts are best delineated by MR imaging.The presence of a nonenhancing intradural extramedullary mass that is midline, anterior to the spinal cord, iso or slightly hyperintense to CSF on all sequences, and associated with vertebral anomalies is highly suggestive of the diagnosis. Half the enterogenous cysts in our series occur without associated bony anomalies.