title: Magnetic resonance imaging-guided neurosurgery in the magnetic fringe fields: the next step in neuronavigation.
abstract: OBJECTIVE
  We describe the development of an alternative approach to intraoperative magnetic resonance imaging (iMR)-guided neurosurgery and report our initial experience with 22 craniotomies and 16 brain biopsies. The advantages and disadvantages of each approach are examined.
  
  
  METHODS
  An iMR suite houses a 0.2-T open configuration system (Siemens Medical Systems, Erlangen, Germany) and is equipped with anesthetic gases and a magnetic resonance imaging (MRI)-compatible anesthesia machine and monitor. Standard operating instruments and equipment were tested for safety and compatibility in the magnetic fringe fields surrounding the open MRI system. We then performed brain biopsies and craniotomies in the iMR suite.
  
  
  RESULTS
  Standard operating equipment functioned properly in the 0.5- to 10-mT zone and was not affected by the magnet's attractive force. Twenty-two craniotomies and 16 brain biopsies were performed in the interventional suite, using serial intraoperative MRI guidance, without injury to patients or operating room staff.
  
  
  CONCLUSIONS
  Full neurosurgical procedures may be performed in the weak fringe fields surrounding an MRI system, using standard operating room equipment. This approach to iMR-guided neurosurgery offers a significant cost advantage over retrofitting an entire operative suite with "MRI-compatible" surgical equipment. The surgeon's familiarity with standard equipment and the reliability of the equipment are additional advantages. Neurosurgery in the fringe fields allows the neurosurgeon to utilize serial MRI with a minimum of inconvenience, disruption, and change to the standard neurosurgical procedure. Serial intraoperative imaging to visualize the changes in the brain that are associated with neurosurgical intervention seems to enhance the ability to safely and effectively accomplish neurosurgical goals.
authors.affiliation: Division of Neurosurgery, University of California, Los Angeles, School of Medicine, 90095-7039, USA.
authors.forename: G J
authors.initials: GJ
authors.lastname: Rubino
authors.forename: K
authors.initials: K
authors.lastname: Farahani
authors.forename: D
authors.initials: D
authors.lastname: McGill
authors.forename: B
authors.initials: B
authors.lastname: Van De Wiele
authors.forename: J P
authors.initials: JP
authors.lastname: Villablanca
authors.forename: A
authors.initials: A
authors.lastname: Wang-Mathieson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D001921:Brain / Q000473:pathology / Q000601:surgery; D002648:Child; D003399:Craniotomy; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008280:Magnetics; D008297:Male; D008875:Middle Aged; D009493:Neurosurgery; D009873:Operating Rooms; D011183:Postoperative Complications; D012449:Safety; D013523:Surgical Equipment