碘水剂椎管造影误入硬膜下腔的影像学分析

An Analynsis of Myelography with Misintroduction of Isovist contrast medium into subdusal space

目的：观察碘水剂椎管造影误入硬膜下腔的Ｘ线造影表现，并分析其误入原因和鉴别诊断方法。方法：从２８１例椎管造影中发现７例经脊髓造影ＣＴ（ＣＴＭ）证实有造影剂误入硬膜下腔者，进行Ｘ线征象分析。结果：发现其造影呈多样化影像表现，可产生多种假象：７例椎管造影中，假性硬膜外梗阻征５例，假性血管畸形４例，马尾神经不显影者５例等。结论：碘水剂椎管造影误入硬膜下腔的Ｘ线造影表现极易误诊为硬膜外梗阻和血管畸形，充分认识其Ｘ线表现，并与ＣＦＭ对照分析，有重要的鉴别诊断意义。用细针操作，可减少其发生率。

Purpose: To review the X-ray findings of myelography with misintroduction of Isovist into subdural space.Methods: CT Myelographies (CTM) confirmedthe misintroduction of Isovist in 7 cases of 281 myelographies, The causes of misintroductioin and its differential diagnosis were discussed. Results: The 7 myelographic findingS were venous: 5 cases showedpseudoepidural obetruction, 4 cases with arteriovenous malformations (AVM), non-visualization of coccygeal nerves in 5 cases.The typical image of CT myelography with misintroduction of Isovist into subdural space was the appearance of a two-layer structure. Conclusion: The myelography with misintroduction of contrast medium could be easily misinterpreted as epidural obstructionand AVM. Recognizing these images and comparing myelography with its CTM could help the differential diagnosis. Operatingwith fine needle and careful technique might lessen the chance of misintroduction.