title: Diffusion-weighted magnetic resonance imaging of symptomatic nerve root of patients with lumbar disk herniation.
abstract: BACKGROUND
  Diffusion-weighted imaging (DWI) can provide valuable structural information that may be useful for evaluating pathological changes of the lumbar nerve root. Diffusion-weighted magnetic resonance (MR) neurography has recently been introduced as an alternative way to visualize nerves, but to date, quantitative DWI and MR neurography have not been applied to evaluate the pathology of lumbar nerve roots.
  
  
  METHODS
  Our purpose was to visualize lumbar nerve roots and to analyze their morphology by MR neurography, and to measure the apparent diffusion coefficient (ADC) of lumbar nerve roots compressed by herniated disks using 1.5-T MR imaging. Ten consecutive patients (median age, 48.0 and range, 20-72 years) with monoradicular symptoms caused by a lumbar herniated disk and 14 healthy volunteers were studied. Regions of interests were placed on the lumbar roots at dorsal root ganglia (DRG) and distal spinal nerves on DWI to quantify mean ADC values. The spinal nerve roots were also visualized by MR neurography.
  
  
  RESULTS
  In the patients, mean ADC values were significantly greater in the compressed DRG and distal spinal nerves than in intact nerves. MR neurography also showed abnormalities such as nerve swelling at and below the compression in the symptomatic nerve root. Increased ADC values were considered to be because of edema and Wallerian degeneration of compressed nerve roots.
  
  
  CONCLUSIONS
  DWI is a potential tool for analysis of the pathophysiology of lumbar nerve roots compressed by herniated disks.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan. yawara_eguchi@yahoo.co.jp
authors.forename: Yawara
authors.initials: Y
authors.lastname: Eguchi
authors.forename: Seiji
authors.initials: S
authors.lastname: Ohtori
authors.forename: Masaomi
authors.initials: M
authors.lastname: Yamashita
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Yamauchi
authors.forename: Munetaka
authors.initials: M
authors.lastname: Suzuki
authors.forename: Sumihisa
authors.initials: S
authors.lastname: Orita
authors.forename: Hiroto
authors.initials: H
authors.lastname: Kamoda
authors.forename: Gen
authors.initials: G
authors.lastname: Arai
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Masayuki
authors.initials: M
authors.lastname: Miyagi
authors.forename: Nobuyasu
authors.initials: N
authors.lastname: Ochiai
authors.forename: Shunji
authors.initials: S
authors.lastname: Kishida
authors.forename: Gen
authors.initials: G
authors.lastname: Inoue
authors.forename: Yoshitada
authors.initials: Y
authors.lastname: Masuda
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Ochi
authors.forename: Takashi
authors.initials: T
authors.lastname: Kikawa
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Toyone
authors.forename: Masashi
authors.initials: M
authors.lastname: Takaso
authors.forename: Yasuchika
authors.initials: Y
authors.lastname: Aoki
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D019299:Decompression, Surgical / Q000379:methods; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007405:Intervertebral Disc Displacement / Q000473:pathology* / Q000601:surgery; D008159:Lumbar Vertebrae / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D013126:Spinal Nerve Roots / Q000473:pathology*; D055815:Young Adult
chemical_list: D003287:Contrast Media