title: Neurite Orientation Dispersion and Density Imaging Color Maps to Characterize Brain Diffusion in Neurologic Disorders.
abstract: Neurite orientation dispersion and density imaging (NODDI) has recently been developed to overcome diffusion technique limitations in modeling biological systems. This manuscript reports a preliminary investigation into the use of a single color-coded map to represent NODDI-derived information.
  
  
  
  An optimized diffusion-weighted imaging protocol was acquired in several clinical neurological contexts including demyelinating disease, neoplastic process, stroke, and toxic/metabolic disease. The NODDI model was fitted to the diffusion datasets. NODDI is based on a three-compartment diffusion model and provides maps that quantify the contributions to the total diffusion signal in each voxel. The NODDI compartment maps were combined into a single 4-dimensional volume visualized as RGB image (red for anisotropic Gaussian diffusion, green for non-Gaussian anisotropic diffusion, and blue for isotropic Gaussian diffusion), in which the relative contributions of the different microstructural compartments can be easily appreciated.
  
  
  
  The NODDI color maps better describe the heterogeneity of neoplastic as well inflammatory lesions by identifying different tissue components within areas apparently homogeneous on conventional imaging. Moreover, NODDI color maps seem to be useful for identifying vasogenic edema differently from tumor-infiltrated edema. In multiple sclerosis, the NODDI color maps enable a visual assessment of the underlying microstructural changes, possibly highlighting an increased inflammatory component, within lesions and potentially in normal-appearing white matter.
  
  
  
  The NODDI color maps could make this technique valuable in a clinical setting, providing comprehensive and accessible information in normal and pathological brain tissues in different neurological pathologies.
authors.affiliation: Department of Neurology, University of California, San Francisco, CA.|Department of Medical Imaging, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada.|Biomedical Sciences Phd, Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Caverzasi
authors.affiliation: Department of Neurology, University of California, San Francisco, CA.
authors.forename: Nico
authors.initials: N
authors.lastname: Papinutto
authors.affiliation: Neuroradiology Unit and CERMAC, Vita-Salute San Raffaele University and IRCCS San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Castellano
authors.affiliation: Department of Neurology, University of California, San Francisco, CA.
authors.forename: Alyssa H
authors.initials: AH
authors.lastname: Zhu
authors.affiliation: Neuroradiology Unit and CERMAC, Vita-Salute San Raffaele University and IRCCS San Raffaele Scientific Institute, Milan, Italy.|Nuclear Medicine Department, IRCCS San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Scifo
authors.affiliation: Unit of Surgical Neuro-Oncology Humanitas Research Hospital, Rozzano, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Riva
authors.affiliation: Unit of Surgical Neuro-Oncology Humanitas Research Hospital, Rozzano, Italy.|Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Bello
authors.affiliation: Neuroradiology Unit and CERMAC, Vita-Salute San Raffaele University and IRCCS San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Falini
authors.affiliation: Department of Medical Imaging, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Aditya
authors.initials: A
authors.lastname: Bharatha
authors.affiliation: Department of Neurology, University of California, San Francisco, CA.|Graduate Program in Bioengineering, UC Berkeley/UC San Francisco, CA.
authors.forename: Roland G
authors.initials: RG
authors.lastname: Henry
mesh_terms: D001921:Brain / Q000473:pathology* / Q000503:physiopathology*; D001927:Brain Diseases / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D016501:Neurites / Q000473:pathology* / Q000502:physiology*; D059906:Neuroimaging
keywords: NODDI; color map; diffusion; glioma; neurite