title: High-resolution MRI predicts steroid injection response in carpal tunnel syndrome patients.
abstract: OBJECTIVE
  To correlate median nerve T2 signal and shape at the carpal tunnel with steroid injection (SI) response in carpal tunnel syndrome (CTS) patients.
  
  
  METHODS
  One hundred and sixty-three CTS wrists of 92 consecutive patients who were scheduled to undergo SI were prospectively evaluated with 3-T magnetic resonance imaging (MRI) and a nerve conduction study. All patients underwent axial high-resolution T2-weighted MRI (in-plane resolution of 0.25 × 0.25 mm). The CTS wrists were classified into three groups according to the nerve T2 signal and the flattening ratio at the hook of hamate level: group 1, high and oval; group 2, high and flat; group 3, low and flat. Clinical response to SI was evaluated at 6 months after injection.
  
  
  RESULTS
  One hundred and thirteen of the 163 wrists (69.3%) responded well to SI. The percentage of improvement was 81.7% (49/60) in group 1, 69.9% (51/73) in group 2, and 43.3% (13/30) in group 3 (P < 0.01). On stepwise logistic regression analysis high-resolution MRI was the only significant independent factor for SI response in CTS patients (P < 0.01).
  
  
  CONCLUSIONS
  High-resolution MRI correlates well with SI response in CTS patients and seems useful for predicting SI response.
  
  
  CONCLUSIONS
  • MRI may help determine appropriate care in carpal tunnel syndrome. • MRI helps in therapeutic decision-making whenever steroid injection is considered. • T2 signal decrease of the median nerve correlates with poor outcome. • T2 signal decrease of median nerve may reflect fibrosis and amyloid deposition.
authors.affiliation: Department of Radiology, University of Occupational and Environmental Health School of Medicine, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan, a-taka@med.uoeh-u.ac.jp.
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Aoki
authors.forename: Takahisa
authors.initials: T
authors.lastname: Oshige
authors.forename: Atsushi
authors.initials: A
authors.lastname: Matsuyama
authors.forename: Hodaka
authors.initials: H
authors.lastname: Oki
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Kinoshita
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takahashi
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Hayashida
authors.forename: Akinori
authors.initials: A
authors.lastname: Sakai
authors.forename: Masanori
authors.initials: M
authors.lastname: Hisaoka
authors.forename: Yukunori
authors.initials: Y
authors.lastname: Korogi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D002349:Carpal Tunnel Syndrome / Q000188:drug therapy* / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D005938:Glucocorticoids / Q000008:administration & dosage*; D006801:Humans; D007270:Injections, Intra-Articular; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008475:Median Nerve / Q000187:drug effects / Q000473:pathology*; D008875:Middle Aged; D009431:Neural Conduction / Q000187:drug effects*; D009460:Neurologic Examination; D010525:Peripheral Nerves / Q000187:drug effects / Q000473:pathology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D014955:Wrist Joint / Q000187:drug effects / Q000473:pathology
chemical_list: D005938:Glucocorticoids