title: Visualization of white matter tracts using a non-diffusion weighted magnetic resonance imaging method: does intravenous gadolinium injection four hours prior to the examination affect the visualization of white matter tracts?
abstract: OBJECTIVE
  Visualization of white matter (WM)-tracts such as the corticospinal tract (CST), medial lemniscus (ML), and superior cerebellar peduncle (SCP) using delayed enhanced (DE)-heavily T2-weighted three-dimensional fluid-attenuated inversion-recovery (hT2w-3D-FLAIR) imaging has recently been reported. In that report, all patients were clinically suspected of having Ménière's disease, because DE-hT2w-3D-FLAIR imaging of the inner ear has been reported to separately visualize perilymph and endolymph fluid and can identify the presence of endolymphatic hydrops. Therefore, the previous report could not rule out the possible effect of delayed enhancement. From this perspective, the purpose of this study was to elucidate if the use of gadolinium affects the visualization of WM-tracts on hT2w-3D-FLAIR.
  
  
  METHODS
  The records of nine patients with suspected Ménière's disease who underwent plain (P) and DE-hT2w-3D-FLAIR by 3-Tesla were retrospectively analyzed. The regions of interest were set on the CST, ML, and SCP, and on contiguous brain parenchyma: The thalamus (Th), pontine parenchyma (PP), and cerebellar parenchyma (CP), respectively. The signal intensity ratio between each WM-tract and the relevant contiguous brain parenchyma was calculated for both P- and DE-hT2w-3D-FLAIR images, and statistically compared using paired t-tests.
  
  
  RESULTS
  The CST/Th signal intensity ratio was 3.75±0.67 on P-hT2w-3D-FLAIR and 3.62±0.50 on DE-hT2w-3D-FLAIR (p = 0.24). The ML/PP signal intensity ratio was 2.19±0.59 on P-hT2w-3D-FLAIR and 2.08±0.53 on DE-hT2w-3D-FLAIR (p = 0.25). The SCP/CP signal intensity ratio was 4.08±0.91 on P-hT2w-3D-FLAIR and 4.04±0.96 on DE-hT2w-3D-FLAIR (p = 0.43). There were no significant differences in the signal intensity ratios between P- and DE-hT2w-3D-FLAIR images.
  
  
  CONCLUSIONS
  The use of gadolinium is not necessary for visualization of WM-tracts using hT2w-3D-FLAIR, and P-hT2w-3D-FLAIR without gadolinium may have future clinical applications as an imaging procedure.
authors.affiliation: Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamazaki
authors.affiliation: Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Naganawa
authors.affiliation: Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Kawai
authors.affiliation: Department of Radiological Technology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Ikeda
authors.affiliation: Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Kiminori
authors.initials: K
authors.lastname: Bokura
authors.affiliation: Department of Radiological Technology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Haruo
authors.initials: H
authors.lastname: Isoda
authors.affiliation: Department of Otorhinolaryngology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nakashima
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D005682:Gadolinium / Q000008:administration & dosage*; D006801:Humans; D021621:Imaging, Three-Dimensional; D007275:Injections, Intravenous; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008575:Meniere Disease / Q000175:diagnosis / Q000473:pathology; D008875:Middle Aged; D013997:Time Factors; D066127:White Matter / Q000473:pathology*
chemical_list: D003287:Contrast Media; D005682:Gadolinium