title: Geometrical constraints for robust tractography selection.
abstract: Tract-based analysis from DTI has become a widely employed procedure to study the white matter of the brain and its alterations in neurological and neurosurgical pathologies. Automatic tractography selection methods, where a subset of detected tracts corresponding to a specific white matter structure are selected, are a key component of the DTI processing pipeline. Using automatic tractography selection, repeatable results free of intra and inter-expert variability can be obtained rapidly, without the need for cumbersome manual segmentation. Many of the current approaches for automatic tractography selection rely on a previous registration procedure using an atlas; hence, these methods are likely very sensitive to the accuracy of the registration. In this paper we show that the performance of the registration step is critical to the overall result. This effect can in turn affect the calculation of scalar parameters derived subsequently from the selected tracts and often used in clinical practice; we show that such errors may be comparable in magnitude to the subtle differences found in clinical studies to differentiate between healthy and pathological. As an alternative, we propose a tractography selection method based on the use of geometrical constraints specific for each fiber bundle. Our experimental results show that the approach proposed performs with increased robustness and accuracy with respect to other approaches in the literature, particularly in the presence of imperfect registration.
authors.affiliation: Laboratorio de Procesado de Imagen (LPI), ETSI Telecomunicación at Universidad de Valladolid, Campus Miguel Delibes s/n., 47011 Valladolid, Spain. Electronic address: rodlui@tel.uvas.es.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: de Luis-García
authors.affiliation: Laboratory of Mathematics in Imaging, 1249 Boylston St, Boston, MA 02215 USA. Electronic address: westin@bwh.harvard.edu.
authors.forename: Carl-Fredrik
authors.initials: CF
authors.lastname: Westin
authors.affiliation: Laboratorio de Procesado de Imagen (LPI), ETSI Telecomunicación at Universidad de Valladolid, Campus Miguel Delibes s/n., 47011 Valladolid, Spain. Electronic address: caralb@tel.uva.es.
authors.forename: Carlos
authors.initials: C
authors.lastname: Alberola-López
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated
keywords: DTI; Tractography selection; White matter analysis