title: [Preoperative functional magnetic resonance imaging in patients with brain tumors].
abstract: BACKGROUND
  Functional Magnetic Resonance Imaging (fMRI) allows important functions in the brain cortex to be mapped noninvasively. The purpose with this work was to investigate a possible correlation between the distance from the tumour margin to fMRI activity and postoperative neurological deficits by means of a standardised method for measurement of distance. A second purpose was to investigate the influence of preoperative fMRI on the neurosurgical decision-making process.
  
  
  METHODS
  Retrospective study of 25 patients. The inclusion criteria were surgery or biopsy after fMRI plus a three-month postoperative assessment. A total of 14 patients complied with these requirements (six men and eight women, the mean age was 39 years). fMRI raw data was collected using a three tesla magnetic resonance scanner (Signa HDx R14M5, GE Healthcare). The distance from the tumour margin to fMRI activation was measured using GE-reformat version 4.2 after raw data had been postprocessed using GE BrainwavePA version 1.3.08130. The neurosurgeons valuation of fMRI in the preoperative decision-making process was obtained using a standard questionnaire.
  
  
  RESULTS
  There was a trend of association between distance from tumour to eloquent functional areas and the patients' postoperative neurological outcome (Fisher's exact test: distance < 15 mm, p = 0.43; distance < 10 mm, p = 0.14). fMRI proved very useful when deciding whether to operate or not (42%), when deciding the surgical approach (50%) and when deciding the extent of the surgical approach (83%).
  
  
  CONCLUSIONS
  The standardised method for measurement of distance between tumour margin and fMRI activity can contribute to the preoperative risk assessment in patients with brain tumours.
authors.affiliation: Arhus Universitetshospital, Aalborg Sygehus, Radiologisk Afdeling, Denmark. sorl@rn.dk
authors.forename: Søren Ravn
authors.initials: SR
authors.lastname: Laustsen
authors.forename: Preben
authors.initials: P
authors.lastname: Sørensen
authors.forename: Torben
authors.initials: T
authors.lastname: Fründ
authors.forename: Henrik B W
authors.initials: HB
authors.lastname: Larsson
authors.forename: Thorkil
authors.initials: T
authors.lastname: Christensen
authors.forename: Elna-Marie
authors.initials: EM
authors.lastname: Larsson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000473:pathology / Q000601:surgery; D001931:Brain Mapping / Q000379:methods; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D002648:Child; D003657:Decision Making; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D038361:Neuronavigation / Q000379:methods; D009837:Oligodendroglioma / Q000473:pathology / Q000601:surgery; D011300:Preoperative Care / Q000379:methods; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult