title: Utility of preoperative magnetic resonance imaging myelography for identifying dural defects in patients with spinal extradural arachnoid cysts: case report.
abstract: OBJECTIVE
  Preoperative magnetic resonance imaging (MRI) myelography scans demonstrated a dural defect in a 50-year-old man with an epidural arachnoid cyst who had a 29-year history of untreated weakness and numbness both lower limbs.
  
  
  METHODS
  MRI scans showed a dorsal intraspinal extradural cystic lesion at the level from Th11 to L1. Although preoperative cine-MRI scans failed to display the dural defect, an MRI myelography scan showed cerebrospinal fluid in the subarachnoid space containing a cyst.
  
  
  RESULTS
  The site of shunting between the subarachnoid space and the cyst was visualized as a pulsating flow void to the right of Th12. We removed the cyst wall and closed the dural defect via laminectomy.
  
  
  CONCLUSIONS
  Because the preoperative MRI myelography scan correctly identified the existence and location of the dural defect, we conclude that MRI myelography is helpful for detecting dural defects in patients with epidural arachnoid cysts.
authors.affiliation: Department of Neurosurgery, Kushiro Rosai Hospital, Kushiro, Japan. miyamich@med.hokudai.ac.jp
authors.forename: Michiyuki
authors.initials: M
authors.lastname: Miyamoto
authors.forename: Kyongsong
authors.initials: K
authors.lastname: Kim
authors.forename: Ryoji
authors.initials: R
authors.lastname: Matsumoto
authors.forename: Masanori
authors.initials: M
authors.lastname: Isobe
authors.forename: Toyohiko
authors.initials: T
authors.lastname: Isu
mesh_terms: D016080:Arachnoid Cysts / Q000175:diagnosis* / Q000601:surgery*; D004388:Dura Mater / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D006801:Humans; D007796:Laminectomy; D008159:Lumbar Vertebrae; D008279:Magnetic Resonance Imaging; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009192:Myelography; D011300:Preoperative Care; D013116:Spinal Cord / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D013118:Spinal Cord Diseases / Q000175:diagnosis* / Q000601:surgery*; D013904:Thoracic Vertebrae; D014057:Tomography, X-Ray Computed