title: DTI-based deterministic fibre tracking of the medial forebrain bundle.
abstract: BACKGROUND
  Deep brain stimulation (DBS) of the medial forebrain bundle (MFB) was reported to reduce symptoms in psychiatric disorders. The aim of our study was to find standardised parameters for diffusion tensor imaging (DTI) based fibre tracking to reliably visualise the MFB.
  
  
  METHODS
  Twenty-two cerebral hemispheres in 11 patients were investigated. Three different regions of interest (ROIs) were defined as seed regions for fibre tracking: the ipsilateral and contralateral superior cerebellar peduncle (SCP) and the nucleus raphe dorsalis (NRD). From each seed region the fibres were followed separately through the ventral tegmental area (VTA = second ROI) and their further courses and volumina were documented and compared. Minimal fibre length was set at 30 mm and the FA threshold at 0.12.
  
  
  RESULTS
  The fibre tracts starting in seed regions in the ipsilateral SCP and the NRD follow a similar course along the lateral wall of the third ventricle (hypothalamus) and the anterior limb of the internal capsule (ALIC) to inferior fronto-medial brain areas. These fibres are in accordance with the course of the MFB as described in various anatomical atlases. Consistently, a branch leaves the main fibre tract laterally to take a course through the capsula externa to the temporo-parietal cortex. Fibre tracts starting from the contralateral SCP follow a more superior and lateral course, including the dentato-rubro-thalamic and the pyramidal tract.
  
  
  CONCLUSIONS
  Deterministic fibre tracking with standardised ROIs provides constant and reproducible delineations of the medial forebrain bundle. Its visualisation might help to adjust targeting in DBS for psychiatric disorders.
authors.affiliation: Department of Neurosurgery, University Hospital of Regensburg, Franz-Josef-Strauss Allee 11, 93053, Regensburg, Germany, Judith.anthofer@ukr.de.
authors.forename: Judith Maria
authors.initials: JM
authors.lastname: Anthofer
authors.forename: Kathrin
authors.initials: K
authors.lastname: Steib
authors.forename: Claudia
authors.initials: C
authors.lastname: Fellner
authors.forename: Max
authors.initials: M
authors.lastname: Lange
authors.forename: Alexander
authors.initials: A
authors.lastname: Brawanski
authors.forename: Juergen
authors.initials: J
authors.lastname: Schlaier
mesh_terms: D000328:Adult; D000368:Aged; D002493:Central Nervous System Diseases / Q000175:diagnosis / Q000628:therapy*; D046690:Deep Brain Stimulation / Q000379:methods*; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007031:Hypothalamus / Q000503:physiopathology; D008297:Male; D008474:Medial Forebrain Bundle / Q000503:physiopathology*; D008875:Middle Aged; D011712:Pyramidal Tracts / Q000503:physiopathology