title: Practical visualization of internal structure of white matter for image interpretation: staining a spin-echo T2-weighted image with three echo-planar diffusion-weighted images.
abstract: OBJECTIVE
  To our knowledge, no method satisfactory for clinical use has been developed to visualize white matter fiber tracts with diffusion-weighted MR imaging. The purpose of this study was to determine whether superposition of a spin-echo T2-weighted image and a color-coded image derived from three orthogonal diffusion-weighted images could show fiber tract architecture of the brain with an image quality appropriate for accurate reading with a computer monitor.
  
  
  METHODS
  MR images from 50 consecutive cases were reviewed. Three diffusion-weighted images per section were acquired with three orthogonal motion-probing gradients. These images were registered to a corresponding spin-echo T2-weighted image. A color-coded image was synthesized from three diffusion-weighted images by assigning red, green, or blue to each diffusion-weighted image and then adding a spin-echo T2-weighted image with a weighting factor. The ability of the superposed image to delineate the white matter pathways was evaluated on the basis of the known anatomy of these pathways and qualitatively compared with that of the spin-echo T2-weighted image.
  
  
  RESULTS
  The main white matter fiber pathways, in particular the superior longitudinal fascicle, corpus callosum, tapetum, optic radiation, and internal capsule, were more clearly and easily identified on the superposed image than on the spin-echo T2-weighted image. The time required to produce the superposed image was approximately 40 minutes.
  
  
  CONCLUSIONS
  Superposition of a spin-echo T2-weighted image and a color-coded image created from three orthogonal diffusion-weighted images showed structures of the brain that were not clearly visible on the spin-echo T2-weighted image alone. Such superposition presents images that are easy to interpret correctly.
authors.affiliation: Department of Radiology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Tamura
authors.forename: Shoki
authors.initials: S
authors.lastname: Takahashi
authors.forename: Noriko
authors.initials: N
authors.lastname: Kurihara
authors.forename: Shogo
authors.initials: S
authors.lastname: Yamada
authors.forename: Jun
authors.initials: J
authors.lastname: Hatazawa
authors.forename: Toshio
authors.initials: T
authors.lastname: Okudera
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology*; D001932:Brain Neoplasms / Q000175:diagnosis; D002561:Cerebrovascular Disorders / Q000175:diagnosis; D002648:Child; D002675:Child, Preschool; D038524:Diffusion Magnetic Resonance Imaging; D017352:Echo-Planar Imaging; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009434:Neural Pathways / Q000473:pathology*; D012016:Reference Values; D012680:Sensitivity and Specificity