title: Magnetic resonance imaging/magnetic resonance angiography fusion technique for intraoperative navigation during microsurgical resection of cerebral arteriovenous malformations.
abstract: OBJECTIVE
  Microsurgical resection of arteriovenous malformations (AVMs) is facilitated by real-time image guidance that demonstrates the precise size and location of the AVM nidus. Magnetic resonance images have routinely been used for intraoperative navigation, but there is no single MRI sequence that can provide all the details needed for characterization of the AVM. Additional information detailing the specific location of the feeding arteries and draining veins would be valuable during surgery, and this detail may be provided by fusing MR images and MR angiography (MRA) sequences. The current study describes the use of a technique that fuses contrast-enhanced MR images and 3D time-of-flight MR angiograms for intraoperative navigation in AVM resection.
  
  
  METHODS
  All patients undergoing microsurgical resection of AVMs at the Dartmouth Cerebrovascular Surgery Program were evaluated from the surgical database. Between 2009 and 2011, 15 patients underwent surgery in which this contrast-enhanced MRI and MRA fusion technique was used, and these patient form the population of the present study.
  
  
  RESULTS
  Image fusion was successful in all 15 cases. The additional data manipulation required to fuse the image sets was performed on the morning of surgery with minimal added setup time. The navigation system accurately identified feeding arteries and draining veins during resection in all cases. There was minimal imaging-related artifact produced by embolic materials in AVMs that had been preoperatively embolized. Complete AVM obliteration was demonstrated on intraoperative angiography in all cases.
  
  
  CONCLUSIONS
  Precise anatomical localization, as well as the ability to differentiate between arteries and veins during AVM microsurgery, is feasible with the aforementioned MRI/MRA fusion technique. The technique provides important information that is beneficial to preoperative planning, intraoperative navigation, and successful AVM resection.
authors.affiliation: Section of Neurosurgery, Department of Radiology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire 03756, USA.
authors.forename: Kimon
authors.initials: K
authors.lastname: Bekelis
authors.forename: Symeon
authors.initials: S
authors.lastname: Missios
authors.forename: Atman
authors.initials: A
authors.lastname: Desai
authors.forename: Clifford
authors.initials: C
authors.lastname: Eskey
authors.forename: Kadir
authors.initials: K
authors.lastname: Erkmen
mesh_terms: D000328:Adult; D000368:Aged; D006801:Humans; D021621:Imaging, Three-Dimensional; D002538:Intracranial Arteriovenous Malformations / Q000175:diagnosis* / Q000601:surgery*; D007430:Intraoperative Care / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008866:Microsurgery / Q000379:methods*; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult