title: Thoracic spine localization using preoperative placement of fiducial markers and subsequent CT. A technical report.
abstract: METHODS
  A retrospective case series evaluating the use of fiducial markers with subsequent computed tomography (CT) or CT myelography for intraoperative localization.
  
  
  OBJECTIVE
  To evaluate the safety and utility of preoperative fiducial placement, confirmed with CT myelography, for intraoperative localization of thoracic spinal levels.
  
  
  BACKGROUND
  Thoracic spine surgery is associated with serious complications, not the least of which is the potential for wrong-level surgery. Intraoperative fluoroscopy is often used but can be unreliable due to the patient's body habitus and anatomical variation.
  
  
  METHODS
  Sixteen patients with thoracic spine pathology requiring surgical intervention underwent preoperative fiducial placement at the pedicle of the level of interest in the interventional radiology suite. CT or CT myelogram was then done to evaluate fiducial location relative to the level of pathology. Surgical treatment followed at a later date in all patients.
  
  
  RESULTS
  All patients underwent preoperative fiducial placement and CT or CT myelography, which was done on an outpatient basis in 14 of the 16 patients. Intraoperatively, fiducial localization was easily and quickly done with intraoperative fluoroscopy leading to correct localization of spinal level in all cases. All patients had symptomatic improvement following surgery. There were no complications from preoperative localization or operative intervention.
  
  
  CONCLUSIONS
  Preoperative placement of fiducial markers confirmed with a CT or CT myelogram allows for reliable and fast intraoperative localization of the spinal level of interest with minimal risks and potential complications to the patient. In most cases, a noncontrast CT should be sufficient. This should be an equally reliable means of localization while further decreasing potential for complications. CT myelography should be reserved for pathology that is not evident on noncontrast CT. Accuracy of localization is independent of variations in rib number or vertebral segmentation. The technique is a safe, reliable, and rapid means of localizing spinal level during surgery.
authors.affiliation: Department of Neurological Surgery, Georgetown University Hospital, Washington, District of Columbia, United States.
authors.forename: Amjad Nasr
authors.initials: AN
authors.lastname: Anaizi
authors.affiliation: Department of Neurological Surgery, Georgetown University Hospital, Washington, District of Columbia, United States.
authors.forename: Christopher
authors.initials: C
authors.lastname: Kalhorn
authors.affiliation: Department of Radiology, Georgetown University Hospital, Washington, District of Columbia, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: McCullough
authors.affiliation: Department of Neurological Surgery, Georgetown University Hospital, Washington, District of Columbia, United States.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Voyadzis
authors.affiliation: Department of Neurological Surgery, Georgetown University Hospital, Washington, District of Columbia, United States.
authors.forename: Faheem A
authors.initials: FA
authors.lastname: Sandhu
mesh_terms: D000328:Adult; D017586:Diskectomy / Q000379:methods / Q000592:standards*; D005260:Female; D057918:Fiducial Markers / Q000009:adverse effects / Q000592:standards*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000592:standards*; D009192:Myelography; D011300:Preoperative Care / Q000009:adverse effects / Q000592:standards*; D013904:Thoracic Vertebrae / Q000473:pathology / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome