title: Brain biopsy sampling by using prospective stereotaxis and a trajectory guide.
abstract: OBJECTIVE
  The authors describe their initial results obtained using a skull-mounted trajectory guide for intraoperative magnetic resonance (MR) imaging-guided brain biopsy sampling. The device was used in conjunction with a new methodology known as prospective stereotaxis for surgical trajectory alignment.
  
  
  METHODS
  Between January 1999 and March 2000, 38 patients underwent 40 brain biopsy procedures in which prospective stereotaxis was performed with the trajectory guide in a short-bore 1.5-tesla MR imager. In most cases, orthogonal T2-weighted half-Fourier acquisition single-shot turbo spin-echo (HASTE) images were used to determine the desired trajectory and align the device. The surgical trajectory was defined as a line connecting three points: the target, pivot, and alignment stem points. In all cases, surgical specimens were submitted for frozen section and pathological examination. Postoperative turbofluid-attenuated inversion-recovery and gradient-echo images were obtained to exclude the presence of hemorrhage. Trajectory determination and alignment was simple and efficient, requiring less than 5 minutes. Confirmatory HASTE images were obtained along the biopsy needle as it was being advanced or after reaching the target. All biopsy procedures yielded diagnostic tissue. One patient with a lesion near the motor strip experienced a transient hemiparesis of the hand related to passage of the biopsy needle, and another sustained a fatal postoperative myocardial infarction. No patient suffered a clinically significant or radiologically visible hemorrhage.
  
  
  CONCLUSIONS
  In combination with prospective stereotaxis, the trajectory guide provided a safe and accurate way to perform brain biopsy procedures.
authors.affiliation: Department of Neurosurgery, University of Minnesota School of Medicine, Minneapolis, USA. hallx003@tc.umn.edu
authors.forename: W A
authors.initials: WA
authors.lastname: Hall
authors.forename: H
authors.initials: H
authors.lastname: Liu
authors.forename: A J
authors.initials: AJ
authors.lastname: Martin
authors.forename: R E
authors.initials: RE
authors.lastname: Maxwell
authors.forename: C L
authors.initials: CL
authors.lastname: Truwit
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D001921:Brain / Q000473:pathology*; D002648:Child; D015331:Cohort Studies; D003936:Diagnosis, Computer-Assisted; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013238:Stereotaxic Techniques