title: Minimally invasive precision brain access using prospective stereotaxy and a trajectory guide.
abstract: OBJECTIVE
  To evaluate the capabilities of MR-guided "prospective stereotaxy" methods for accessing brain structures for biopsy or electrode implantation.
  
  
  METHODS
  MR-guided biopsy and deep brain stimulator (DBS) electrode implantations were performed with a trajectory guide and real-time MR guidance. Imaging methods were used to plan the selected path through the brain, appropriately orient the trajectory guide, and monitor the device insertion to assure technical success and screen for hemorrhage. Assessments of technical success rate, targeting accuracy, and complications associated with this technique were performed.
  
  
  RESULTS
  A total of 187 biopsy procedures were performed with guidance via prospective stereotaxy methods. All brain biopsies were diagnostic and two patients sustained superficial wound infections that were treated successfully with antibiotics. One patient died postoperatively of a myocardial infarction despite preoperative medical clearance. A total of 42 DBS electrode insertions were performed in patients with Parkinson's disease or dystonia. The difference between planned and actual electrode position averaged 1.2 mm +/- 0.7 mm on the first pass and only a single brain penetration was required in 90% of electrode insertions. Complications included a single asymptomatic hemorrhage and two early infections, with the latter addressed by an adjustment to sterile practice.
  
  
  CONCLUSIONS
  Prospective stereotaxy, in combination with a trajectory guide, has been proven capable of efficiently and accurately targeting structures throughout the brain.
authors.affiliation: Department of Radiology, University of California, San Francisco, California 94143, USA. Alastair.Martin@radiology.ucsf.edu
authors.forename: Alastair J
authors.initials: AJ
authors.lastname: Martin
authors.forename: Walter A
authors.initials: WA
authors.lastname: Hall
authors.forename: Christopher
authors.initials: C
authors.lastname: Roark
authors.forename: Philip A
authors.initials: PA
authors.lastname: Starr
authors.forename: Paul S
authors.initials: PS
authors.lastname: Larson
authors.forename: Charles L
authors.initials: CL
authors.lastname: Truwit
mesh_terms: D000328:Adult; D000368:Aged; D001707:Biopsy, Needle; D001921:Brain / Q000473:pathology / Q000601:surgery*; D004567:Electrodes, Implanted; D005260:Female; D006801:Humans; D053783:Magnetic Resonance Imaging, Interventional; D008297:Male; D008875:Middle Aged; D013238:Stereotaxic Techniques / Q000295:instrumentation*