title: Preoperative assessment of motor cortex and pyramidal tracts in central cavernoma employing functional and diffusion-weighted magnetic resonance imaging.
abstract: BACKGROUND
  Functional MRI (fMRI) combines anatomic with functional information and has therefore been widely used for preoperative planning of patients with mass lesions affecting functionally important brain regions. However, the courses of functionally important fiber tracts are not visualized. We therefore propose to combine fMRI with diffusion-weighted MRI (DWI) that allows visualization of large fiber tracts and to implement this data in a neuronavigation system.
  
  
  METHODS
  DWI was successfully performed at a field strength of 1.5 Tesla, employing a spin-echo sequence with gradient sensitivity in six noncollinear directions to visualize the course of the pyramidal tracts, and was combined with echo-planar T2* fMRI during a hand motor task in a patient with central cavernoma.
  
  
  RESULTS
  Fusion of both data sets allowed visualization of the displacement of both the primary sensorimotor area (M1) and its large descending fiber tracts. Intraoperatively, these data were used to aid in neuronavigation. Confirmation was obtained by intraoperative electrical stimulation. Postoperative MRI revealed an undisrupted pyramidal tract in the neurologically intact patient.
  
  
  CONCLUSIONS
  The combination of fMRI with DWI allows for assessment of functionally important cortical areas and additional visualization of large fiber tracts. Information about the orientation of fiber tracts in normal appearing white matter in patients with tumors within the cortical motor system cannot be obtained by other functional or conventional imaging methods and is vital for reducing operative morbidity as the information about functional cortex. This technique might, therefore, have the prospect of guiding neurosurgical interventions, especially when linked to a neuronavigation system.
authors.affiliation: Department of Neuroradiology, University Hospital of the University of Technology, Aachen, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Möller-Hartmann
authors.forename: Timo
authors.initials: T
authors.lastname: Krings
authors.forename: Volker A
authors.initials: VA
authors.lastname: Coenen
authors.forename: Lothar
authors.initials: L
authors.lastname: Mayfrank
authors.forename: Jürgen
authors.initials: J
authors.lastname: Weidemann
authors.forename: Heidi
authors.initials: H
authors.lastname: Kränzlein
authors.forename: Armin
authors.initials: A
authors.lastname: Thron
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000150:complications / Q000473:pathology* / Q000601:surgery; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006392:Hemangioma, Cavernous / Q000150:complications / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D009044:Motor Cortex / Q000473:pathology* / Q000503:physiopathology; D010291:Paresis / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D011300:Preoperative Care; D011712:Pyramidal Tracts / Q000473:pathology* / Q000503:physiopathology; D012422:Rupture, Spontaneous / Q000150:complications