title: Probabilistic vs. deterministic fiber tracking and the influence of different seed regions to delineate cerebellar-thalamic fibers in deep brain stimulation.
abstract: This study compared tractography approaches for identifying cerebellar-thalamic fiber bundles relevant to planning target sites for deep brain stimulation (DBS). In particular, probabilistic and deterministic tracking of the dentate-rubro-thalamic tract (DRTT) and differences between the spatial courses of the DRTT and the cerebello-thalamo-cortical (CTC) tract were compared. Six patients with movement disorders were examined by magnetic resonance imaging (MRI), including two sets of diffusion-weighted images (12 and 64 directions). Probabilistic and deterministic tractography was applied on each diffusion-weighted dataset to delineate the DRTT. Results were compared with regard to their sensitivity in revealing the DRTT and additional fiber tracts and processing time. Two sets of regions-of-interests (ROIs) guided deterministic tractography of the DRTT or the CTC, respectively. Tract distances to an atlas-based reference target were compared. Probabilistic fiber tracking with 64 orientations detected the DRTT in all twelve hemispheres. Deterministic tracking detected the DRTT in nine (12 directions) and in only two (64 directions) hemispheres. Probabilistic tracking was more sensitive in detecting additional fibers (e.g. ansa lenticularis and medial forebrain bundle) than deterministic tracking. Probabilistic tracking lasted substantially longer than deterministic. Deterministic tracking was more sensitive in detecting the CTC than the DRTT. CTC tracts were located adjacent but consistently more posterior to DRTT tracts. These results suggest that probabilistic tracking is more sensitive and robust in detecting the DRTT but harder to implement than deterministic approaches. Although sensitivity of deterministic tracking is higher for the CTC than the DRTT, targets for DBS based on these tracts likely differ.
authors.affiliation: Department of Neurosurgery, Medical Center, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
authors.forename: Juergen R
authors.initials: JR
authors.lastname: Schlaier
authors.affiliation: Department of Experimental Psychology, University of Regensburg, Regensburg, Germany.
authors.forename: Anton L
authors.initials: AL
authors.lastname: Beer
authors.affiliation: Department of Neurosurgery, Medical Center, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
authors.forename: Rupert
authors.initials: R
authors.lastname: Faltermeier
authors.affiliation: Institute of Radiology, Medical Center, University of Regensburg, Regensburg, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Fellner
authors.affiliation: Department of Neurosurgery, Medical Center, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Steib
authors.affiliation: Department of Neurosurgery, Medical Center, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
authors.forename: Max
authors.initials: M
authors.lastname: Lange
authors.affiliation: Department of Experimental Psychology, University of Regensburg, Regensburg, Germany.
authors.forename: Mark W
authors.initials: MW
authors.lastname: Greenlee
authors.affiliation: Department of Neurosurgery, Medical Center, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
authors.forename: Alexander T
authors.initials: AT
authors.lastname: Brawanski
authors.affiliation: Department of Neurosurgery, Medical Center, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
authors.forename: Judith M
authors.identifier: 0000-0002-4357-1968
authors.initials: JM
authors.lastname: Anthofer
mesh_terms: D002531:Cerebellum / Q000000981:diagnostic imaging*; D046690:Deep Brain Stimulation; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods / Q000592:standards; D008875:Middle Aged; D009412:Nerve Fibers / Q000502:physiology*; D009415:Nerve Net / Q000000981:diagnostic imaging; D009434:Neural Pathways / Q000000981:diagnostic imaging; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000628:therapy; D013788:Thalamus / Q000000981:diagnostic imaging*
keywords: deep brain stimulation; dentate-rubro-thalamic tract; deterministic tractography; movement disorders; probabilistic tractography