title: Improving the clinical potential of ultra-high field fMRI using a model-free analysis method based on response consistency.
abstract: OBJECTIVE
  To develop an analysis method that is sensitive to non-model-conform responses often encountered in ultra-high field presurgical planning fMRI. Using the consistency of time courses over a number of experiment repetitions, it should exclude low quality runs and generate activation maps that reflect the reliability of responses.
  
  
  METHODS
  7 T fMRI data were acquired from six healthy volunteers: three performing purely motor tasks and three a visuomotor task. These were analysed with the proposed approach (UNBIASED) and the GLM.
  
  
  RESULTS
  UNBIASED results were generally less affected by false positive results than the GLM. Runs that were identified as being of low quality were confirmed to contain little or no activation. In two cases, regions were identified as activated in UNBIASED but not GLM results. Signal changes in these areas were time-locked to the task, but were delayed or transient.
  
  
  CONCLUSIONS
  UNBIASED is shown to be a reliable means of identifying consistent task-related signal changes regardless of response timing. In presurgical planning, UNBIASED could be used to rapidly generate reliable maps of the consistency with which eloquent brain regions are activated without recourse to task timing and despite modified hemodynamics.
authors.affiliation: Department of Biomedical Imaging and Image-guided Therapy, High Field Magnetic Resonance Centre, Medical University of Vienna, Lazarettgasse 14/BT32, 1090, Vienna, Austria.
authors.forename: Pedro Lima
authors.initials: PL
authors.lastname: Cardoso
authors.affiliation: Study Group Clinical fMRI, Department of Neurology, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
authors.forename: Florian Ph S
authors.initials: FP
authors.lastname: Fischmeister
authors.affiliation: Department of Biomedical Imaging and Image-guided Therapy, High Field Magnetic Resonance Centre, Medical University of Vienna, Lazarettgasse 14/BT32, 1090, Vienna, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Dymerska
authors.affiliation: Study Group Clinical fMRI, Department of Neurology, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Geißler
authors.affiliation: Study Group Clinical fMRI, Department of Neurology, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
authors.forename: Moritz
authors.initials: M
authors.lastname: Wurnig
authors.affiliation: Department of Biomedical Imaging and Image-guided Therapy, High Field Magnetic Resonance Centre, Medical University of Vienna, Lazarettgasse 14/BT32, 1090, Vienna, Austria.
authors.forename: Siegfried
authors.initials: S
authors.lastname: Trattnig
authors.affiliation: Study Group Clinical fMRI, Department of Neurology, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
authors.forename: Roland
authors.initials: R
authors.lastname: Beisteiner
authors.affiliation: Department of Biomedical Imaging and Image-guided Therapy, High Field Magnetic Resonance Centre, Medical University of Vienna, Lazarettgasse 14/BT32, 1090, Vienna, Austria. simon.robinson@meduniwien.ac.at.
authors.forename: Simon Daniel
authors.initials: SD
authors.lastname: Robinson
mesh_terms: D000328:Adult; D000465:Algorithms; D016477:Artifacts; D001921:Brain / Q000000981:diagnostic imaging; D001931:Brain Mapping / Q000379:methods; D005189:False Positive Reactions; D005260:Female; D064368:Healthy Volunteers; D006439:Hemodynamics; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008959:Models, Neurological; D009038:Motion; D057234:Preoperative Period; D015203:Reproducibility of Results; D016896:Treatment Outcome; D055815:Young Adult
keywords: Modified BOLD response; Presurgical planning; UNBIASED; Ultra-high field; fMRI analysis