title: Intraoperative low-field MR-guided frameless stereotactic biopsy for intracerebral lesions.
abstract: BACKGROUND
  To present our intraoperative low-field magnetic resonance imaging (ioMRI) technique for stereotactic brain biopsy in various intracerebral lesions.
  
  
  METHODS
  Seventy-eight consecutive patients underwent stereotactic biopsies with the PoleStar N-20/N-30 ioMRI system and data were evaluated retrospectively. Biopsy technique included ioMRI before surgery, followed by insertion of the biopsy cannula in the lesion, and ioMRI before and after biopsy. Statistical analysis was performed to compare subgroups using Excel and SPSS statistic software.
  
  
  RESULTS
  In all patients, stereotactic biopsy was possible, with a mean intraoperative surgery time of 86.2 ± 28.6 min and a mean hospital stay of 11.6 ± 4.6 days. In 97.4 % (n = 76), histology was conclusive, representing 58 brain tumors and 18 other pathologies. Five patients were biopsied previously without conclusive diagnosis, and all biopsies were conclusive this time. Mean cross-sectional lesion size in MRI T1 with contrast (n = 64) was 6.9 ± 5.7 cm(2), and in lesions without T1 contrast enhancement (n = 14), T2 mean cross-sectional lesion size was 5.5 ± 3.9 cm(2). Mean distance from the cortex surface to the lesion was 3.4 ± 1.2 cm. One patient suffered from a postoperative wound dehiscence; neither clinically or radiologically significant hemorrhage after surgery, nor intraoperative complications occurred.
  
  
  CONCLUSIONS
  Low-field ioMR-guided frameless stereotactic biopsy accurately diagnosed different intracerebral lesions without major complications for the patients, and within an acceptable surgery time and hospital stay. In repeated non-conclusive biopsies in particular, low-field ioMRI offers a technique for arriving at a diagnosis.
authors: Department of Neurosurgery, University Hospital Zurich, Frauenklinikstr.10, 8091, Zurich, Switzerland. Jankarl.burkhardt@gmail.com
authors: Jan-Karl
authors: JK
authors: Burkhardt
authors: Marian C
authors: MC
authors: Neidert
authors: Christoph M
authors: CM
authors: Woernle
authors: Oliver
authors: O
authors: Bozinov
authors: René-Ludwig
authors: RL
authors: Bernays
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy / Q000379:methods; D001932:Brain Neoplasms / Q000473:pathology* / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D038361:Neuronavigation / Q000295:instrumentation / Q000379:methods; D013238:Stereotaxic Techniques / Q000295:instrumentation*; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult