title: Preoperative mapping of cortical motor function: prospective comparison of functional magnetic resonance imaging and [15O]-H2O-positron emission tomography in the same co-ordinate system.
abstract: BACKGROUND
  Two of the most widely accepted approaches to map eloquent cortical areas preoperatively are positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). As yet, no study has compared these two modalities within the same frame of reference in tumour patients.
  
  
  OBJECTIVE
  We employed [15O]-H2O-PET and fMRI in patients undergoing presurgical evaluation and compared the results with those obtained by direct electrical cortical stimulation (DECS).
  
  
  METHODS
  Twenty-five patients with tumours of different aetiology near the central region were investigated. fMRI and PET were processed using the same methods, i.e. statistical parametric mapping (SPM) without anatomical normalization, and transformed into the same frame of reference.
  
  
  RESULTS
  fMRI activity was found in more cranial and lateral sections, i.e. closer to the brain surface, in comparison with PET, which demonstrated parenchymal activation. The mean localization difference between fMRI and PET was 8.1 +/- 4.6 mm (range, 2-18 mm). fMRI and [15O]-H2O-PET could reliably identify the central sulcus, as demonstrated by DECS.
  
  
  CONCLUSIONS
  fMRI and [15O]-H2O-PET demonstrate comparable results and are sensitive and reliable tools to map the central region, especially in cases of infiltrating brain tumours. However, fMRI is more prone to artefacts, such as the visualization of draining veins, which may explain the more cranial and lateral activation visualized by fMRI, whereas PET depicts capillary perfusion changes and therefore shows activation closer to the parenchyma.
authors.affiliation: Department of Neurosurgery, University Hospital Aachen, Germany. m.reinges@web.de
authors.forename: Marcus H T
authors.initials: MH
authors.lastname: Reinges
authors.forename: Timo
authors.initials: T
authors.lastname: Krings
authors.forename: Philipp T
authors.initials: PT
authors.lastname: Meyer
authors.forename: Mathias
authors.initials: M
authors.lastname: Schreckenberger
authors.forename: Veit
authors.initials: V
authors.lastname: Rohde
authors.forename: Jürgen
authors.initials: J
authors.lastname: Weidemann
authors.forename: Osama
authors.initials: O
authors.lastname: Sabri
authors.forename: Edith J M
authors.initials: EJ
authors.lastname: Mulders
authors.forename: Udalrich
authors.initials: U
authors.lastname: Buell
authors.forename: Armin
authors.initials: A
authors.lastname: Thron
authors.forename: Joachim M
authors.initials: JM
authors.lastname: Gilsbach
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001931:Brain Mapping / Q000379:methods*; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000601:surgery*; D019054:Evoked Potentials, Motor; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D010104:Oxygen Radioisotopes; D019990:Perioperative Care / Q000379:methods; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D014867:Water
chemical_list: D010104:Oxygen Radioisotopes; D019275:Radiopharmaceuticals; D014867:Water