title: Diffusion Tensor Imaging in Patients with Glioblastoma Multiforme Using the Supertoroidal Model.
abstract: OBJECTIVE
  Diffusion Tensor Imaging (DTI) is a powerful imaging technique that has led to improvements in the diagnosis and prognosis of cerebral lesions and neurosurgical guidance for tumor resection. Traditional tensor modeling, however, has difficulties in differentiating tumor-infiltrated regions and peritumoral edema. Here, we describe the supertoroidal model, which incorporates an increase in surface genus and a continuum of toroidal shapes to improve upon the characterization of Glioblastoma multiforme (GBM).
  
  
  METHODS
  DTI brain datasets of 18 individuals with GBM and 18 normal subjects were acquired using a 3T scanner. A supertoroidal model of the diffusion tensor and two new diffusion tensor invariants, one to evaluate diffusivity, the toroidal volume (TV), and one to evaluate anisotropy, the toroidal curvature (TC), were applied and evaluated in the characterization of GBM brain tumors. TV and TC were compared with the mean diffusivity (MD) and fractional anisotropy (FA) indices inside the tumor, surrounding edema, as well as contralateral to the lesions, in the white matter (WM) and gray matter (GM).
  
  
  RESULTS
  The supertoroidal model enhanced the borders between tumors and surrounding structures, refined the boundaries between WM and GM, and revealed the heterogeneity inherent to tumor-infiltrated tissue. Both MD and TV demonstrated high intensities in the tumor, with lower values in the surrounding edema, which in turn were higher than those of unaffected brain parenchyma. Both TC and FA were effective in revealing the structural degradation of WM tracts.
  
  
  CONCLUSIONS
  Our findings indicate that the supertoroidal model enables effective tensor visualization as well as quantitative scalar maps that improve the understanding of the underlying tissue structure properties. Hence, this approach has the potential to enhance diagnosis, preoperative planning, and intraoperative image guidance during surgical management of brain lesions.
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA, United States of America.
authors.forename: Choukri
authors.initials: C
authors.lastname: Mekkaoui
authors.affiliation: Department of Neurosurgery, Hôpital de la Timone Adultes Marseille, Marseille, Bouches-du-Rhône, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Metellus
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA, United States of America.|Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States of America.
authors.forename: William J
authors.initials: WJ
authors.lastname: Kostis
authors.affiliation: Laboratory of Cognitive Neuroscience, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
authors.forename: Roberto
authors.initials: R
authors.lastname: Martuzzi
authors.affiliation: Department of Radiology, University Hospital Center of Nîmes and Research Team EA 2415, Nîmes, Gard, France.
authors.forename: Fabricio R
authors.initials: FR
authors.lastname: Pereira
authors.affiliation: Department of Radiology, University Hospital Center of Nîmes and Research Team EA 2415, Nîmes, Gard, France.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Beregi
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA, United States of America.
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Reese
authors.affiliation: Department of Diagnostic Radiology, Yale University School of Medicine, Magnetic Resonance Research Center, New Haven, CT, United States of America.
authors.forename: Todd R
authors.initials: TR
authors.lastname: Constable
authors.affiliation: Department of Computer Science, Institute of Mathematics and Statistics, University of São Paulo, São Paulo, Brazil.
authors.forename: Marcel P
authors.initials: MP
authors.lastname: Jackowski
mesh_terms: D016880:Anisotropy; D001921:Brain / Q000473:pathology; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005909:Glioblastoma / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D008954:Models, Biological; D066127:White Matter / Q000473:pathology